Be able to recognize experimental vs survey vs case study vs
naturalistic observation research ?The essential differences are as
follows:
Experiments vs Observation and Survey:
With experiments you manipulate one variable then measure
another, this means you know how changing one variable causally
affects another and you can draw inferences about cause and effect.
In observational studies and surveys you are not manipulating any
variables so you can only draw correlational conclusions which
indicate associations between variables rather than causal
links.
Observation vs Survey:
In observational research you observe people in the natural
environment, unually with them being unaware of this so you see
their natural behaviour. e.g. If you see them use a candy machine
you know they eat candy. With surveys they know they are being
surveyed so you can get all sorts of things affecting the results
such as demand characteristics. e.g. They may say they don't eat
candy but how can you be sure?
Case Study Definition:A case study is an in-depth study of one
person. Much of Freud's work and theories were developed through
individual case studies.In a case study, nearly every aspect of the
subject's life and history is analyzed to seek patterns and causes
for behavior. The hope is that learning gained from studying one
case can be generalized to many others. Unfortunately, case studies
tend to be highly subjective and it is difficult to generalize
results to a larger population.Types of Case Studies Explanatory:
Used to do causal investigations.
Exploratory: A case study that is sometimes used as a prelude to
further, more in-depth research. This allows researchers to gather
more information before developing their research questions and
hypotheses.
Descriptive: Involves starting with a descriptive theory. The
subjects are then observed and the information gathered is compared
to the pre-existing theory.
Intrinsic: A type of case study in which the researcher has a
personal interest in the case.
Collective: Involves studying a group of individuals.
Instrumental: Occurs when the individual or group allows
researchers to understand more than what is initially obvious to
observers.Case Study Methods Prospective: A type of case study in
which an individual or group of people is observed in order to
determine outcomes. For example, a group of individuals might be
watched over an extended period of time to observe the progression
of a particular disease.
Retrospective: A type of case study that involves looking at
historical information. For example, researchers might start with
an outcome, such as a disease, and then backwards at information
about the individuals life to determine risk factors that may have
contributed to the onset of the illness.Know that research findings
of one study must be replicated in other studies for us to be
confident that the findings really are trustworthy ... test more
than once to be absolutely certain / 100% sureUnderstand the
concept of representsativeness of one's sample --Representative
sampling is a type of statistical sampling in which a researcher
attempts to select individuals which are representative of a larger
population. In statistical sampling, people gather data from a
small group and try to extrapolate the results to make
generalizations about a larger group. Truly representative sampling
is extremely hard to accomplish, and researchers may dedicate a
great deal of time and funding to getting the most representative
sample possible.As a research tool, statistical sampling is
extremely valuable. It allows people to study a population without
studying every single individual in that population. Average
individuals are quite familiar with statistical sampling, even
though they might not be aware of it; the next time you open a
newspaper, look for an article which talks about the result of a
study. A line like 67% of American pet owners sleep with their pets
is the result of a representative sample of pet-owning Americans.
Incidentally, that number comes from the Sealy Mattress Company.In
order to get a representative sample, the researchers must first
identify the population being sampled. In the example above, the
researchers wanted to collect data on how many Americans slept with
their animals, so the population was American pet owners. The next
step for the researchers is finding a way to randomly select people
from this population so that they can survey these individuals for
data.If the researchers collect too heavily from one segment of the
population, such as all American pet owners going to veterinary
clinics in the city of Chicago, the result is not a
representativesample of the population being studied. Therefore,
researchers must think of a multitude of methods for collecting
data to ensure that evenly samples all aspects of the population
being studied.When you read a study which has been conducted with
the use of representative sampling, it is a good idea to find out
which methods the researchers used. Sampling error can yield
incorrect results, and therefore you want to know how the data was
collected, who it was collected from, and what sort of controls
were in place to ensure that the sampling was representative. By
using critical thinking to look at statistics and representative
sampling, you will be able to determine whether or not they are
truly useful and applicable.Chapter 6 - Learning Classical
Conditioning Behaviorism is a school of thought in psychology based
on the assumption that learning occurs through interactions with
the environment. Two other assumptions of this theory are that the
environment shapes behavior and that taking internal mental states
such as thoughts, feelings and emotions into consideration is
useless in explaining behavior.One of the best-known aspects of
behavioral learning theory is classical conditioning. Discovered by
Russian physiologist Ivan Pavlov, classical conditioning is a
learning process that occurs through associations between an
environmental stimulus and a naturally occurring stimulus.It's
important to note that classical conditioning involves placing a
neutral signal before a naturally occurring reflex. In Pavlov's
classic experiment with dogs, the neutral signal was the sound of a
tone and the naturally occurring reflex was salivating in response
to food. By associating the neutral stimulus with the environmental
stimulus (the presentation of food), the sound of the tone alone
could produce the salivation response.In order to understand how
more about how classical conditioning works, it is important to be
familiar with the basic principles of the process.The Unconditioned
StimulusThe unconditioned stimulus is one that unconditionally,
naturally, and automatically triggers a response. For example, when
you smell one of your favorite foods, you may immediately feel very
hungry. In this example, the smell of the food is the unconditioned
stimulus.The Unconditioned ResponseThe unconditioned response is
the unlearned response that occurs naturally in response to the
unconditioned stimulus. In our example, the feeling of hunger in
response to the smell of food is the unconditioned response.The
Conditioned StimulusThe conditioned stimulus is previously neutral
stimulus that, after becoming associated with the unconditioned
stimulus, eventually comes to trigger a conditioned response. In
our earlier example, suppose that when you smelled your favorite
food, you also heard the sound of a whistle. While the whistle is
unrelated to the smell of the food, if the sound of the whistle was
paired multiple times with the smell, the sound would eventually
trigger the conditioned response. In this case, the sound of the
whistle is the conditioned stimulus.The Conditioned ResponseThe
conditioned response is the learned response to the previously
neutral stimulus. In our example, the conditioned response would be
feeling hungry when you heard the sound of the whistle.Classical
Conditioning in the Real WorldIn reality, people do not respond
exactly like Pavlov's dogs. There are, however, numerous real-world
applications for classical conditioning. For example, many dog
trainers use classical conditioning techniques to help people train
their pets.These techniques are also useful in the treatment
ofphobias or anxiety problems. Teachers are able to apply classical
conditioning in the class by creating a positive classroom
environment to help students overcome anxiety or fear. Pairing an
anxiety-provoking situation, such as performing in front of a
group, with pleasant surroundings helps the student learn new
associations. Instead of feeling anxious and tense in these
situations, the child will learn to stay relaxed and calm.More
About Classical ConditioningClassical conditioning can be used to
increase the amount of a behavior, but it can also be used to
decrease behavior. Learn more about classical conditioning
phenomena.Understand the basic process involved in acquiring a
classically conditioned response to something ---Behaviorists have
described a number of different phenomena associated with classical
conditioning. Some of these elements involve the initial
establishment of the response, while others describe the
disappearance of a response. These elements are important in
understanding the classical conditioning
process.AcquisitionAcquisition is the initial stage of learning
when a response is first established and gradually strengthened.
For example, imagine that you are conditioning a dog to salivate in
response to the sound of a bell. You repeatedly pair the
presentation of food with the sound of the bell. You can say the
response has been acquired as soon as the dog begins to salivate in
response to the bell tone. Once the response has been acquired, you
can gradually reinforce the salivation response to make sure the
behavior is well learned.ExtinctionExtinction is when the
occurrences of a conditioned response decrease or disappear. In
classical conditioning, this happens when a conditioned stimulus is
no longer paired with an unconditioned stimulus. For example, if
the smell of food (the unconditioned stimulus) had been paired with
the sound of a whistle (the conditioned stimulus), it would
eventually come to evoke the conditioned response of hunger.
However, if the unconditioned stimulus (the smell of food) were no
longer paired with the conditioned stimulus (the whistle),
eventually the conditioned response (hunger) would
disappear.Sponteneous RecoverySpontaneous Recovery is the
reappearance of the conditioned response after a rest period or
period of lessened response. If the conditioned stimulus and
unconditioned stimulus are no longer associated, extinction will
occur very rapidly after a spontaneous recovery.Stimulus
GeneralizationStimulus Generalization is the tendency for the
conditioned stimulus to evoke similar responses after the response
has been conditioned. For example, if a child has been conditioned
to fear a stuffed white rabbit, the child will exhibit fear of
objects similar to the conditioned
stimulus.DiscriminationDiscrimination is the ability to
differentiate between a conditioned stimulus and other stimuli that
have not been paired with an unconditioned stimulus. For example,
if a bell tone were the conditioned stimulus, discrimination would
involve being able to tell the difference between the bell tone and
other similar sounds.GO to page 237 in the book How can a
conditioned response become extinct ?? ----Extinction in Classical
ConditioningConsider this example of extinction in classical
conditioning.If the smell of food (the unconditioned stimulus) had
been paired with the sound of a whistle (the conditioned stimulus),
it would eventually come to evoke the conditioned response of
hunger. However, if the unconditioned stimulus (the smell of food)
was no longer paired with the conditioned stimulus (the whistle),
then the conditioned response (hunger) would eventually
disappear.Extinction in Operant ConditioningConsider this example
of extinction in operant conditioning:A teacher has been using
positive reinforcement to encourage good behavior in her classroom.
When a student raises his or her hand instead of shouting out the
answers, the teacher rewards the student with a fruit-flavored
candy. After several days of this, the children become sick of the
candy, and stop raising their hands. Because the children have
become satiated and the candy is no longer rewarding, extinction of
the trained behavior has occurred.Understand recovery and renewal
effects are pretty common, and what makes a renewal (relapse )
effect more likely ??? ---THE RENEWAL EFFECTAssociative learning
occurs when an organism links two or more items of information. The
simplest forms of associative learning are classical conditioning
and instrumental conditioning. Classical conditioning is also known
as Pavlovian conditioning in honor of Ivan Pavlov (18491936) who
was the first person to conduct extensive research of this nature.
In a typical experiment with dogs, Pavlov would present a neutral
auditory stimulus such as a metronome immediately before applying
sand or food powder to the dog's tongue, which produced salivation.
After a number of these pairings, Pavlov presented the metronome
alone, and the dog now salivated. Pavlov developed terminology for
these components of classical conditioning: The dog experienced a
relatively neutral stimulus or conditioned stimulus (CS, the
metronome) in conjunction with a biologically significant stimulus
or unconditioned stimulus (US, the food powder), which always
produces an unconditioned response (UCR, salivation). After
multiple CS-US pairings (i.e., acquisition), presentation of the CS
alone elicited a response, the conditioned response (CR, also
salivation), which is appropriate for its corresponding US.
Following acquisition of the CR to the metronome CS, Pavlov also
reported that presenting the CS alone a number of times would
eventually eliminate the salivation CR, a procedure termed
extinction.Although most classical conditioning experiments have
used nonhumans, classical conditioning readily occurs in humans
(e.g., Hermans, Craske, Mineka, & Lovibond, 2006). With
nonhumans, many model systems have been developed to explore
classical conditioning, including conditioned eyeblink, conditioned
taste aversion, and conditioned approach/avoidance (Domjan, 2003).
Clearly, these have little classroom application, but the most
common classical conditioning paradigm, conditioned emotional
response, is applicable. Conditioned emotional reactions can be
either positive or negative. A positive conditioned emotional
response is produced by pairing a relatively neutral stimulus with
a US that elicits a positive emotion such as happiness. For
example, a parent may use the preferred taste of cheese to cover
the flavor of broccoli. After a few meals of cheesy broccoli, a
child will be more willing to eat broccoli by itself (for a review
of food preference learning, see Capaldi, 1996). Although it is
possible to produce positive emotional reactions, broad application
of this methodology has not been implemented (other than in
advertising when an attractive model is paired with a product). In
practicality, it may be difficult for a teacher to spend
substantial time during the earliest portions of class to pair
their presence with a positively affective US. One can imagine only
the youngest of children would not see through an instructor plying
them with candy or treats on the first day of class.Instead, the
more commonly studied phenomenon, and the more likely classroom
occurrence, is the negative conditioned emotional response. A
classic example of conditioned fear in humans is the Little Albert
Study conducted by Watson and Rayner (1920). Watson and Rayner
examined if a phobia could be induced in a human, so they borrowed
nine-month-old Albert from the nursery at Johns Hopkins University.
After recording Albert's baseline responses to a range of stimuli
such as animals and neutral objects, conditioning began two months
later. During acquisition, a white rat was paired with a loud noise
US (Watson clanged a steel bar with a hammer) seven times. Five
days later, Albert was tested with a range of stimuli, including
the white rat. Albert cringed and cried in response to the rat,
behaviors that were quite different from his curiosity about the
rat during the baseline phase. They tested long-term retention of
fear 30 days later, and Albert was still scared of the white rat
and other white objects such as a rabbit, white fur coat, and Santa
Claus mask. In addition to demonstrating conditioned fear in
humans, Watson and Rayner planned to examine the conditions
necessary to extinguish Albert's fear. Unfortunately, on the day
prior to the implementation of the extinction phase, Albert was
released from the hospital with his fear intact.Understand the Role
of classical or evaluative conditioning in political and product
ads--- you should be able to diagram the US, UR, CS and CR for
example ads ---Classical Conditioning in AdvertisingAdvertisers are
always looking for new ways to push their products onto the average
citizen. Ads can be seen and heard everywhere from television and
the Internet to blimps and clothing. For decades, advertisers have
been using classical conditioning in advertising to influence
consumers on a subconscious level into buying the advertised
product. Clear examples of this marketing technique is particularly
prominent in ads for foods and drinks, and perhaps even more
obviously so in political campaign ads.Foods and drinks depicted in
ads on television, billboards, and other visual media are known for
being exceptionally deceptive in their tantalizing, refreshing
appearances. (When was the last time you received a Big Mac that
looked as good as the ones you see on TV?) However, altering the
appearance of their products is not the only trick that the
marketing divisions of major food and drink companies use to make
consumers buy their products; they often pair their product in ads
with upbeat music and feel-good imagery. Take, for example, the
Coca-Cola commercial that debuted during 2012s Super Bowl game.
(http://www.youtube.com/watch?v=S2nBBMbjS8w) NE_Bear is very
visibly distraught about his teams performance in the game, but he
clearly is much happier once he gets his paws on an ice-cold bottle
of Coca-Cola. The emotional imagery presented serves as an
unconditioned stimulus which is meant to condition the consumer to
associate Coca-Cola, the conditioned stimulus, with positive
feelings. Perhaps the stronger UCS in the ad is the use of
Beethovens Fifth Symphony, which is a very well-known and respected
piece of classical music. Another commercial which uses similar
techniques is the Budweiser commercial revolving around
prohibition, which also debuted during the 2012 Super Bowl.
(http://www.youtube.com/watch?v=RGgosT-v5sw) The commercial depicts
a massive celebration to commemorate the end of prohibition, which,
just like the Coca-Cola commercial, aims to associate positive
feelings of celebration (the UCS) with the product for sale, in
this case Budweiser (the CS). The Budweiser commercial features
well known, triumphant music, which further mirrors the Coca-Cola
ad.Examples of classical conditioning are even more blatantly
obvious in political ads, specifically in ads aiming to defame
opposing candidates. Ironically, the aspects of classical
conditioning in these ads are often so obvious that many people
consider the ads to be counterproductive, even laughable. One
strong example of classical conditioning in political advertising
is an anti-Obama ad marketed toward women and focusing on
Obamacare. (http://www.youtube.com/watch?v=iys1BWUf-Nc) The entire
video is structured and formatted like a Nazi public announcement.
The Orwellian context and grim color scheme serve as unconditioned
stimuli that are supposed to connect Obama, the conditioned
stimulus, with oppressive, totalitarian government. Another ad,
which targets Mitt Romney, does a better job of showing the more
common stimuli that are used for classical conditioning through
poltial advertising. (http://www.youtube.com/watch?v=PtSeLTOeXBs)
The majority of the ad is simply quotes and statistics about
Romneys career as a businessman, but the presentation of these
statements is where conditioning comes into play. The entire ad
features dull, dark colors like gray and brown, without any music
or any other appetitive stimulus. This is the model followed by
most negative campaign ads.In conclusion, modern advertisements
rely heavily on classical conditioning to influence consumers.
Through the use of visual depiction of emotion, as well as other
audiovisual stimuli, advertisers form a connection between the
advertised product and positive feelings, or in some cases negative
ones.Ope-rant Conditioning What Is Operant Conditioning?Operant
conditioning (sometimes referred to as instrumental conditioning)
is a method of learning that occurs through rewards and punishments
for behavior. Through operant conditioning, an association is made
between a behavior and a consequence for that behavior.Operant
conditioning was coined by behaviorist B.F. Skinner, which is why
you may occasionally hear it referred to as Skinnerian
conditioning. As a behaviorist, Skinner believed that internal
thoughts and motivations could not be used to explain behavior.
Instead, he suggested, we should look only at the external,
observable causes of human behavior.Skinner used the term operant
to refer to any "active behavior that operates upon the environment
to generate consequences" (1953). In other words, Skinner's theory
explained how we acquire the range of learned behaviors we exhibit
each and every day.Examples of Operant ConditioningWe can find
examples of operant conditioning at work all around us. Consider
the case of children completing homework to earn a reward from a
parent or teacher, or employees finishing projects to receive
praise or promotions.In these examples, the promise or possibility
of rewards causes an increase in behavior, but operant conditioning
can also be used to decrease a behavior. The removal of an
undesirable outcome or the use of punishment can be used to
decrease or prevent undesirable behaviors. For example, a child may
be told they will lose recess privileges if they talk out of turn
in class. This potential for punishment may lead to a decrease in
disruptive behaviors.Components of Operant ConditioningSome key
concepts in operant conditioning:Reinforcement is any event that
strengthens or increases the behavior it follows. There are two
kinds of reinforcers:1. Positive reinforcers are favorable events
or outcomes that are presented after the behavior. In situations
that reflect positive reinforcement, a response or behavior is
strengthened by the addition of something, such as praise or a
direct reward.
2. Negative reinforcers involve the removal of an unfavorable
events or outcomes after the display of a behavior. In these
situations, a response is strengthened by the removal of something
considered unpleasant.In both of these cases of reinforcement, the
behavior increases.Punishment, on the other hand, is the
presentation of an adverse event or outcome that causes a decrease
in the behavior it follows. There are two kinds of punishment:1.
Positive punishment, sometimes referred to as punishment by
application, involves the presentation of an unfavorable event or
outcome in order to weaken the response it follows.
2. Negative punishment, also known as punishment by removal,
occurs when an favorable event or outcome is removed after a
behavior occurs.In both of these cases of punishment, the behavior
decreases.Understand the processes involved in learning through
operant conditioning --Psychologists use several key terms to
discuss operant conditioning principles, including reinforcement
and punishment.ReinforcementReinforcement is delivery of a
consequence that increases the likelihood that a response will
occur. Positive reinforcement is the presentation of a stimulus
after a response so that the response will occur more often.
Negative reinforcement is the removal of a stimulus after a
response so that the response will occur more often. In this
terminology, positive and negative dont mean good and bad.
Instead,positive means adding a stimulus, and negative means
removing a stimulus.PunishmentPunishment is the delivery of a
consequence that decreases the likelihood that a response will
occur. Positive and negative punishments are analogous to positive
and negative reinforcement. Positive punishment is the presentation
of a stimulus after a response so that the response will occur less
often. Negative punishment is the removal of a stimulus after a
response so that the response will occur less often.Reinforcement
helps to increase a behavior, while punishment helps to decrease a
behavior.Primary and Secondary Reinforcers and PunishersReinforcers
and punishers are different types of consequences: Primary
reinforcers, such as food, water, and caresses, are naturally
satisfying. Primary punishers, such as pain and freezing
temperatures, are naturally unpleasant. Secondary reinforcers, such
as money, fast cars, and good grades, are satisfying because theyve
become associated with primary reinforcers. Secondary punishers,
such as failing grades and social disapproval, are unpleasant
because theyve become associated with primary punishers. Secondary
reinforcers and punishers are also calledconditioned reinforcers
and punishers because they arise through classical conditioning.Is
It Primary or Secondary?To distinguish between primary and
secondary reinforcers, people can ask themselves this question:
Would a newborn baby find this stimulus satisfying? If the answer
is yes, the reinforcer is primary. If the answer is no, its
secondary. The same idea can be applied to punishers by asking
whether a baby would find the stimulus unpleasant.ShapingShaping is
a procedure in which reinforcement is used to guide a response
closer and closer to a desired response.Example: Lisa wants to
teach her dog, Rover, to bring her the TV remote control. She
places the remote in Rovers mouth and then sits down in her
favorite TVwatching chair. Rover doesnt know what to do with the
remote, and he just drops it on the floor. So Lisa teaches him by
first praising him every time he accidentally walks toward her
before dropping the remote. He likes the praise, so he starts to
walk toward her with the remote more often. Then she praises him
only when he brings the remote close to the chair. When he starts
doing this often, she praises him only when he manages to bring the
remote right up to her. Pretty soon, he brings her the remote
regularly, and she has succeeded in shaping a
response.Reinforcement SchedulesA reinforcement schedule is the
pattern in which reinforcement is given over time. Reinforcement
schedules can be continuous or intermittent. In continuous
reinforcement, someone provides reinforcement every time a
particular response occurs. Suppose Rover, Lisas dog, pushes the
remote under her chair. If she finds this amusing and pats him
every time he does it, she is providing continuous reinforcement
for his behavior. In intermittent or partial reinforcement, someone
provides reinforcement on only some of the occasions on which the
response occurs.Types of Intermittent Reinforcement SchedulesThere
are four main types of intermittent schedules, which fall into two
categories: ratio or interval. In a ratio schedule, reinforcement
happens after a certain number of responses. In an interval
schedule, reinforcement happens after a particular time interval.
In a fixed-ratio schedule, reinforcement happens after a set number
of responses, such as when a car salesman earns a bonus after every
three cars he sells. In a variable-ratio schedule, reinforcement
happens after a particular average number of responses. For
example, a person trying to win a game by getting heads on a coin
toss gets heads every two times, on average, that she tosses a
penny. Sometimes she may toss a penny just once and get heads, but
other times she may have to toss the penny two, three, four, or
more times before getting heads. In a fixed-interval schedule,
reinforcement happens after a set amount of time, such as when an
attorney at a law firm gets a bonus once a year. In a
variable-interval schedule, reinforcement happens after a
particular average amount of time. For example, a boss who wants to
keep her employees working productively might walk by their
workstations and check on them periodically, usually about once a
day, but sometimes twice a day, or some-times every other day. If
an employee is slacking off, she reprimands him. Since the
employees know there is a variable interval between their bosss
appearances, they must stay on task to avoid a reprimand.Response
PatternsThese different types of reinforcement schedules result in
different patterns of responses: Partial or intermittent schedules
of reinforcement result in responses that resist extinction better
than responses resulting from continuous reinforcement.
Psychologists call this resistance to extinction the partial
reinforcement effect. Response rate is faster in ratio schedules
than in interval schedules. Ratio schedules depend on number of
responses, so the faster the subject responds, the more quickly
reinforcement happens. A fixed-interval schedule tends to result in
a scalloped response pattern, which means that responses are slow
in the beginning of the interval and faster just before
reinforcement happens. If people know when reinforcement will
occur, they will respond more at that time and less at other times.
Variable schedules result in steadier response rates than fixed
schedules because reinforcement is less predictable. Responses to
variable schedules also cannot be extinguished easily.ExtinctionAs
in classical conditioning, extinction in operant conditioning is
the gradual disappearance of a response when it stops being
reinforced. In the earlier example, Lisas dog, Rover, started to
put the remote under her chair regularly because she continuously
reinforced the behavior with pats on his head. If she decides that
the game has gone too far and stops patting him when he does it,
hell eventually stop the behavior. The response will be
extinguished.Stimulus DiscriminationIf Lisa enjoys Rovers antics
with the TV remote only in the daytime and not at night when she
feels tired, Rover will put the remote under her chair only during
the day, because daylight has become a signal that tells Rover his
behavior will be reinforced. Daylight has become a discriminative
stimulus. A discriminative stimulus is a cue that indicates the
kind of consequence thats likely to occur after a response. In
operant conditioning, stimulus discrimination is the tendency for a
response to happen only when a particular stimulus is
present.Stimulus GeneralizationSuppose Lisas dog, Rover, began to
put the remote under her chair not only during the day but also
whenever a bright light was on at night, thinking she would
probably pat him. This is called stimulus generalization. In
operant conditioning, stimulus generalization is the tendency to
respond to a new stimulus as if it is the original discriminative
stimulus.---- Know that " reinforcement" , whether pos or neg (1)
has to do with the pay-off or reward the person recieves and ( 2)
increases the behavior that leads to that pay off ---Reinforcement
Choosing a ScheduleKnowing what shaping means ??ShapingShaping
modifies behavior byreinforcingbehaviors that progressive
approximate the target behavior (operant response). Shaping can be
used to train organisms to perform behaviors that would rarely if
ever occur otherwise.
For example, to teach a child to write his or her first name,
you initially give praise for writing the first letter correctly.
After the child has mastered that first step, letter-by-letter you
give praise until the entire name is correctly written.
Shapingis aconditioningprocedure used primarily in
theexperimental analysis of behavior. The method used
isdifferential reinforcementof successive approximations. It was
introduced byB.F. Skinner[1]with pigeons and extended to dogs,
dolphins, humans and other species. In shaping, the form of an
existing response is gradually changed across successive trials
towards a desired target behavior by rewarding exact segments of
behavior. Skinner's explanation of shaping was this:
We first give the bird food when it turns slightly in the
direction of the spot from any part of the cage. This increases the
frequency of such behavior. We then withhold reinforcement until a
slight movement is made toward the spot. This again alters the
general distribution of behavior without producing a new unit. We
continue by reinforcing positions successively closer to the spot,
then by reinforcing only when the head is moved slightly forward,
and finally only when the beak actually makes contact with the
spot. ... The original probability of the response in its final
form is very low; in some cases it may even be zero. In this way we
can build complicated operants which would never appear in the
repertoire of the organism otherwise. By reinforcing a series of
successive approximations, we bring a rare response to a very high
probability in a short time. ... The total act of turning toward
the spot from any point in the box, walking toward it, raising the
head, and striking the spot may seem to be a functionally coherent
unit of behavior; but it is constructed by a continual process of
differential reinforcement from undifferentiated behavior, just as
the sculptor shapes his figure from a lump of clay.[2]Difference
between negative reinforcement and punishment psychology
Definition:Punishment is an important part of B. F. Skinner's
theory operant conditioning. According to Skinner, punishment
involves applying a stimulus after a behavior in order to reduce
likelihood that the behavior will occur again in the future.
People often confuse punishment withnegative reinforcement. One
of the easiest ways to remember the difference between the two is
to note that punishmentalwaysinvolves reducing a behavior while
negative reinforcementalwaysinvolves increasing a behavior.
Learn more about this concept including the types, effectiveness
and potential drawbacks in this definition ofpunishment.
Negative Reinforcementstrengthens a behavior because anegative
conditionis stopped or avoided as a consequence of the behavior.ex:
a rat is shocked until it presses a lever in the cage, the shock
stops. when it lets go of the lever, the shock starts again.
therefore, the rat learns to hold the lever down in order to avoid
being shocked.
Punishment, on the other hand, weakens a behavior because a
negative condition is introduced or experienced as a consequence of
the behavior.Example: a rat is in a cage and when it presses the
lever, it is shocked. When it lets go, the shock stops. It learns
not to press the lever so it wont get punished.
Understand that punishment tends to decrease the punished
behavior How to extinguish operantly conditioned responses ?
Extinctionis observed in bothoperantly conditionedandclassically
conditionedbehavior. When operant behavior that has been previously
reinforced no longer produces reinforcing consequences the behavior
gradually stops occurring.[1]In classical conditioning, when a
conditioned stimulus is presented alone, so that it no longer
predicts the coming of the unconditioned stimulus, conditioned
responding gradually stops. (For example, afterPavlov'sdog was
conditioned to salivate at the sound of a bell, it eventually
stopped salivating to the bell after the bell had been sounded
repeatedly but no food came.)
Extinction
In operant conditioning,extinction(the cessation of a particular
response) occurs when a response no longer results in
reinforcement; it occurs in classical conditioning, as discussed
earlier, when the CS no longer produces a CR. One way to measure
the strength of the learning that has occurred (calledresponse
strength)is to see how many unreinforced trials must occur before
extinction takes place, (calledresistance to extinction).Sometimes,
in both classical and operant conditioning,spontaneous
recoveryoccurs; that is, the response in question begins again even
though there has been no reinforcement (for example, a rat presses
the bar even though the action no longer produces a food
pellet).
InPositive Reinforcementa particular behavior is strengthened by
the consequence of experiencing a positive condition. For
example:
A hungry rat presses a bar in its cage and receives food. The
food is a positive condition for the hungry rat. The rat presses
the bar again, and again receives food. The rat's behavior of
pressing the bar is strengthened by the consequence of receiving
food.InNegative Reinforcementa particular behavior is strengthened
by the consequence of stopping or avoiding a negative condition.
For example:
A rat is placed in a cage and immediately receives a mild
electrical shock on its feet. The shock is a negative condition for
the rat. The rat presses a bar and the shock stops. The rat
receives another shock, presses the bar again, and again the shock
stops. The rat's behavior of pressing the bar is strengthened by
the consequence of stopping the shock.InPunishmenta particular
behavior is weakened by the consequence of experiencing a negative
condition. For example:
A rat presses a bar in its cage and receives a mild electrical
shock on its feet. The shock is a negative condition for the rat.
The rat presses the bar again and again receives a shock. The rat's
behavior of pressing the bar is weakened by the consequence of
receiving a shock.InExtinctiona particular behavior is weakened by
the consequence of not experiencing a positive condition or
stopping a negative condition. For example:
A rat presses a bar in its cage and nothing happens. Neither a
positive or a negative condition exists for the rat. The rat
presses the bar again and again nothing happens. The rat's behavior
of pressing the bar is weakened by the consequence of not
experiencing anything positive or stopping anything
negative.Schedules ofReinforcementInoperant conditioning, schedules
of reinforcement are an important component of the learning
process. When and how often we reinforce a behavior can have a
dramatic impact on the strength and rate of the response.
A schedule of reinforcement is basically a rule stating which
instances of a behavior will be reinforced. In some case, a
behavior might be reinforced every time it occurs. Sometimes, a
behavior might not be reinforced at all. Eitherpositive
reinforcementornegative reinforcementmight be used, depending on
the situation. In both cases, the goal of reinforcement is always
tostrengthenthe behavior and increase the likelihood that it will
occur again in the future.
In real-world settings, behaviors are probably not going to be
reinforced each and every time they occur. For situations where you
are purposely trying to train and reinforce an action, such as in
the classroom, in sports or in animal training, you might opt to
follow a specific reinforcement schedule. As you'll see below, some
schedules are best suited to certain types of training situations.
In some cases, training might call for starting out with one
schedule and switching to another once the desired behavior has
been taught.
Certain schedules of reinforcement may be more effective in
specific situations. There are two types of reinforcement
schedules:
1. Continuous Reinforcement
In continuous reinforcement, the desired behavior is
reinforcedevery single timeit occurs. Generally, this schedule is
best used during the initial stages of learning in order to create
a strong association between the behavior and the response. Once
the response if firmly attached, reinforcement is usually switched
to a partial reinforcement schedule.
2. Partial Reinforcement
In partial reinforcement, the response is reinforced onlypart of
the time. Learned behaviors are acquired more slowly with partial
reinforcement, but the response is more resistant toextinction.
There are four schedules of partial reinforcement:
1. Fixed-ratio schedulesare those where a response is reinforced
only after a specified number of responses. This schedule produces
a high, steady rate of responding with only a brief pause after the
delivery of the reinforcer.
2. Variable-ratio schedulesoccur when a response is reinforced
after an unpredictable number of responses. This schedule creates a
high steady rate of responding. Gambling and lottery games are good
examples of a reward based on a variable ratio schedule.
3. Fixed-interval schedulesare those where the first response is
rewarded only after a specified amount of time has elapsed. This
schedule causes high amounts of responding near the end of the
interval, but much slower responding immediately after the delivery
of the reinforcer.
4. Variable-interval schedulesoccur when a response is rewarded
after an unpredictable amount of time has passed. This schedule
produces a slow, steady rate of response.
Choosing a Schedule
Deciding when to reinforce a behavior can depend upon a number
of factors. In cases where you are specifically trying to teach a
new behavior, a continuous schedule is often a good choice. Once
the behavior has been learned, switching to a partial schedule is
often preferable.
Realistically, reinforcing a behavior every single time it
occurs can be difficult and requires a great deal of attention and
resources. Partial schedules not only tend to lead to behaviors
that are more resistant to extinction, they also reduce the risk
that the subject will become satiated. If the reinforcer being used
is no longer desired or rewarding, the subject may stop performing
the desired behavior.
GO OVER CONCEPT CHECK P 250 256
Observational Learning
Observational LearningByGILLIAN FOURNIERReplicating others novel
behavior through observation and imitation; also known asvicarious
learning, modeling, orsocial learning. This theory was proposed by
Albery Bandura.
Basically, to learn in an observational manner someone must
notice something someone else is doing, remember it or record it in
their mind, and finally replicate the behavior. The behavior may or
may not happen again. The choice to continue exhibiting the
behavior depends on the outcome (positive or negative, reward etc).
The only things that limit this type of learningare the
intelligence level and the level of ability to copy the person well
that the learner possesses.
Example: In a famous experiment, social psychologist Al Bandura
showed young children a video of a woman hitting and kicking an
inflatable Bobo doll. When left alone with a similar doll, children
copied the womans aggressive gestures.I think this site
demonstrates the ideas of social learning theory/observational
learning theory quite well:
Observational Learning
People and animals dont learn only by conditioning; they also
learn by observing others.Observational learningis the process of
learning to respond in a particular way by watching others, who are
called models. Observational learning is also called vicarious
conditioning because it involves learning by watching others
acquire responses through classical or operant conditioning.
Example:Brian might learn not to stand too close to a soccer
goal because he saw another spectator move away after getting
whacked on the head by a wayward soccer ball. The other spectator
stopped standing close to the soccer goal because of operant
conditioninggetting clobbered by the ball acted as positive
punishment for standing too close. Brian was indirectly, or
vicariously, conditioned to move away.
Bandura and the Bobo DollsThe person best known for research on
observational learning is psychologist Albert Bandura, who did some
landmark experiments showing that children who watched adults
behaving aggressively were more likely to behave aggressively
themselves. His most famous experiment was the Bobo doll study.
Bandura let a group of kindergarteners watch a film of an adult
violently attacking an inflatable plastic toy shaped like Bobo the
Clown by hitting it, sitting on it, hammering it, and so forth. He
then let the children into a room with Bobo dolls. The children
precisely imitated the adults behavior, gleefully attacking Bobo.
Their behavior was a type of observational learning.
Featured Study p 259 Did filmed aggression influence childrens
aggressive acts ????? check that book Violent Behavior: SummaryThe
research evidence shows clearly that media violence is a causal
risk factor for aggressive and violent behavior. There is
considerably less evidence concerning violent crimes, but the few
cross-sectional and longitudinal studies that included violent
crime measures also found similar links with media violence. The
size of the media violence effect is as large as or larger than
that of many factors commonly accepted by public policymakers and
the general public as valid risk factors for violent behavior.
Figure 7 illustrates the current best estimates of several risk
factors for youth violence. The figure does not include the
longitudinal violent video game effect because the one relevant
study did not include a specific measure of violence that is
comparable to the other factors. However, several studies have
directly compared video game and TV violence using the same
participants and the same measures; they generally find a somewhat
larger effect for video games. Thus, we expect that the effect of
violent video games on long-term violence will be larger than that
of TV violence and smaller than that of gang membership.
Furthermore, it is likely that overall media violence exposure has
a somewhat larger effect than any individual type of media
violence. In any case, the figure makes clear that media violence
exposure has a larger effect on later violent behavior than does
substance use, abusive parents, poverty, living in a broken home,
or having low IQ.132
Findings
Virtually since the dawn of television, parents, teachers,
legislators, and mental health professionals have been concerned
about the content of television programs and its impact,
particularly on children. Of special concern has been the portrayal
of violence, especially given psychologistAlbert Bandura's workon
social learning and the tendency of children to imitate what they
see. As a result of 15 years of consistently disturbing findings
about the violent content of children's programs, the Surgeon
General's Scientific Advisory Committee on Television and Social
Behavior was formed in 1969 to assess the impact of violence on the
attitudes, values and behavior of viewers. The resulting Surgeon
General's report and a follow-up report in 1982 by the National
Institute of Mental Health identify these major effects of seeing
violence on television:
Children may become less sensitive to the pain and suffering of
others
Children may be more fearful of the world around them
Children may be more likely to behave in aggressive or harmful
ways toward others
Research by psychologists L. Rowell Huesmann, Leonard Eron and
others found that children who watched many hours of violence on
television when they were in elementary school tended to also show
a higher level of aggressive behavior when they became teenagers.
By observing these youngsters into adulthood, Drs. Huesmann and
Eron found that the ones who'd watched a lot of TV violence when
they were eight years old were more likely to be arrested and
prosecuted for criminal acts as adults. Interestingly, being
aggressive as a child did not predict watching more violent TV as a
teenager, suggesting that TV watching may more often be a cause
rather than a consequence of aggressive behavior.
Violent video games are a more recent phenomenon; therefore
there is less research on their effects. However, research by
psychologist Craig A. Anderson and others shows that playing
violent video games can increase a person's aggressive thoughts,
feelings and behavior both in laboratory settings and in actual
life. In fact, a study by Dr. Anderson in 2000 suggests that
violent video games may be more harmful than violent television and
movies because they are interactive, very engrossing and require
the player to identify with the aggressor.
Dr. Anderson and other researches are also looking into how
violent music lyrics affect children and adults. In a 2003 study
involving college students, Anderson found that songs with violent
lyrics increased aggression related thoughts and emotions and this
effect was directly related to the violent content of the lyrics.
"One major conclusion from this and other research on violent
entertainment media is that content matters," says Anderson. "This
message is important for all consumers, but especially for parents
of children and adolescents."
Significance
A typical child in the U.S. watches 28 hours of TV weekly,
seeing as many as 8,000 murders by the time he or she finishes
elementary school at age 11, and worse, the killers are depicted as
getting away with the murders 75% of the time while showing no
remorse or accountability. Such TV violence socialization may make
children immune to brutality and aggression, while others become
fearful of living in such a dangerous society.
With the research clearly showing that watching violent TV
programs can lead to aggressive behavior, The American
Psychological Association passed a resolution in 1985 informing
broadcasters and the public of the potential dangers that viewing
violence on television can have for children. In 1992, the APA's
Task Force on Television and Society published a report that
further confirmed the link between TV violence and aggression.
Practical Application
In 1990, Congress passed the Children's Television Act (CTA),
which outlined new regulations for commercial broadcast stations.
As a result of the CTA (which was updated in 1996), stations are
required to air at least three hours of programming "that furthers
the education and informational needs of children 16 years and
under in any respect, including children's intellectual/cognitive
or social/emotional needs." These programs must be labeled with the
designation "E/I" and have clearly stated, written educational
objectives. These educational programs generally contain both
direct and indirect messages fostering cooperation and compassion
rather than aggression. Parents now have positive options when it
comes to choosing TV programs for their children. Research on
television and violence has also led to the development of
content-based rating systems that allow parents to make judgments
about the programs' content before allowing their children to watch
a show.
Besides warning of the harmful effects of violent media content,
psychology has a strong history of bringing out the best in
television. For example, Daniel R. Anderson, a professor of
psychology at the University of Massachusetts, has worked with
producers of children's programs like Sesame Street and Captain
Kangaroo to help TV shows educate children.
Chapter 11 Development
Understand why we view development as a polygenic,
multi-factorial process of Nature and nurture, not nature vs
nurtureThe term polygenic inheritance is used to refer to the
inheritance of quantitative traits, traits which are influenced by
multiple genes, not just one. In addition to involving multiple
genes, polygenic inheritance also looks at the role of environment
in someone's development.
Because many traits are spread out across a continuum, rather
than being divided into black and white differences, polygenic
inheritance helps to explain the way in which these traits are
inherited and focused. A related concept ispleiotropy, an instance
where one gene influences multiple traits.
Early Mendeliangeneticsfocused on very simple genetic traits
which could be explained by a single gene. For example, a flower
might appear in either orange or yellow form, with no gradation
between the colors. By studying plants and the ways in which they
mutated, early researchers were able to learn more about the gene
which determined flower color. However, by the early twentieth
century, people were well aware that most traits are far too
complex to be determined by a single gene, and the idea of
polygenic inheritance was born.
One easily understood example of polygenic inheritance is
height. People are not just short or tall; they have a variety of
heights which run along a spectrum. Furthermore, height is also
influenced by environment; someone born with tall genes could
become short due to malnutrition or illness, for example, while
someone born with short genes could become tall through genetic
therapy. Basic genetics obviously wouldn't be enough to explain the
wide diversity of human heights, but polygenic inheritance shows
how multiple genes in combination with a person's environment can
influence someone'sphenotype, or physical appearance.
Skin color is another example of polygenic inheritance, as are
many congenital diseases. Because polygenic inheritance is so
complex, it can be a very absorbing and frustrating field of study.
Researchers may struggle to identify all of the genes which play a
role in a particular phenotype, and to identify places where such
genes can go wrong. However, once researchers do learn more about
the circumstances which lead to the expression of particular
traits, it can be a very rewarding experience.
In pleiotropy, on the other hand,onegene is responsible for
multiple things. Several congenital syndromes are examples of
pleiotropy, in which a flaw in one gene causes widespread problems
for a person. For example, sickle cellanemiais a form of
pleiotropy, caused by a distinctive mutation in one gene which
leads to a host of symptoms. In addition to causing mutations,
pleiotropy also occurs in perfectly normal genes, although
researchers tend to use it to track and understand mutations in
particular.
Genes versus Environment
When researchers analyze the origins of disease, the terms used
to describe causation are "genetic" versus "environmental," but the
issues are the same as those in the nature-versus-nurture debate.
Conditions considered to be primarily genetic are ones in which the
presence or absence of genetic mutations determines whether an
individual or population will develop a disease, independent of
environmental exposures or circumstances. A disease considered to
be primarily environmental is one in which people of virtually any
genetic background can develop the disease when they are exposed to
the specific environmental factors that cause it.
Even the conditions and diseases once believed to be at either
end of the continuumcaused by either purely genetic or purely
environmental factorsmay not be exclusively attributable to one or
the other. For example, an automobile accident that results in an
injury might be deemed entirely environmentally caused, but many
geneticists would contend that risk-taking behaviors such as the
propensity to exceed the speed limit are probably genetically
mediated. Furthermore, the course and duration of rehabilitation
and recovery from an injury or illness is also very likely
genetically influenced.
At the other end of the continuum are diseases believed to be
predominantly genetic in origin, such as sickle-cell anemia. While
this disease does not have an environmental cause, there are
environmental triggers that may determine when and how seriously
the disease will strike. For example, sickle-cell attacks are more
likely when the body has an insufficient supply of oxygen, so
people who live at high altitudes or those who engage in intense
aerobic exercise may be at increased risk of attacks. There are
many more conditions for which the risk of developing the disease
is strongly influenced by both genetic and environmental factors.
Multiple genes and environmental factors may be involved in causing
a given condition and its expression.
Understand why it is not the case the one gene or one
environmental factor can account for everything about a certain
developmental process or outcome
Look Above
Gene Expression Many genes play an important role in what you
look like, how intelligent you may become, and perhaps even aspects
of your personality. Increasingly, as work on the human genome
continues, researchers are linking specific genes to psychological
functioning and behavior. Linking, however, is an important
qualifier. In many cases, your genotype, which is your genetic
makeup, does not entirely determine your phenotype, which is who
and what you actually are. The link between genotype and phenotype
can range from simple to exceedingly complex.
Simple Dominance-Recessiveness
Some characteristics are determined by a single gene and are
affected little if at all by the environment of an individual. An
example is the texture of your hair, which is directly determined
by a single gene. The allele for curly hair let's call it C is
dominant over the recessive allele for straight hair call this S.
This means that whenever either or both of the alleles for hair
texture are C, the person will have curly hair, and only when both
alleles are S will a person have straight hair.
Suppose both parents are CS for hair texture. Thus, their child
can be CC, CS, SC, or SS for these alleles. The child will then
have a 75 percent chance of having curly hair (3 combinations out
of 4) and only a 25 percent chance of straight hair (1 out of 4).
If either parent is CC, no SS combination is possible.
Partial Dominance-Recessiveness
Allele combinations can also display partial dominance and
recessiveness. A classic example is the sickle-cell trait, which
occurs primarily among people of African ancestry and is believed
to have developed originally because it enhanced the chances of
survival. Here, the partially recessive gene that produces
sickle-shaped red blood cells which are less efficient than normal
ones at transporting oxygen are at the same time highly resistant
to the mosquito-transmitted malaria that is rampant in Africa's wet
regions. Thus, a person in these regions who has one allele for
normal red blood cells and the other for sickled ones has a better
chance of survival than does a person who has all normal blood
cells. A mix of the two works best in an environment where malaria
is a strong possibility.
Alleles that fall in the category of codominance are neither
dominant nor recessive. The result is a blend of the two, which
happens in certain blood types. If a person has one allele for A
positive and the other for B positive, the person's blood type will
be AB positive.
People with the mix of red blood cells tend to experience joint
pains from time to time and need to avoid high altitudes where the
oxygen content of the air is low. But they survive. In contrast,
those who have all sickled cells as a result of both alleles being
the recessive for the trait have much more severe symptoms and
cannot survive without regular transfusions of normal blood.
Genotype, Phenotype, and Polygenic Expression
Even where one pair of genes is concerned, genotype doesn't
always determine phenotype. Hair type, blood traits, and blood type
aren't affected by environmental factors, but many other physical
characteristics are. For example, genes may set the stage for how
tall or heavy or muscular a person may be, but environmental
considerations such as nutrition and exercise are important factors
too. Malnutrition, especially during early childhood, can make the
phenotype much less than what it was genetically set to be.
Exceptionally good nutrition, exercise, and so on can instead
enhance the phenotype.
An additional complication is polygenic expression, which is
characteristic of psychological traits such as intelligence and
personality. The prevailing view is that a multitude of yet-to-be
identified genes are responsible for complex characteristics such
as these, and in turn that these are strongly affected by the
environment in which a person grows up. The interaction between
heredity and environment will be further examined at various points
in this book.
Can genes be turned on and off in cells?
Each cell expresses, or turns on, only a fraction of its genes.
The rest of the genes are repressed, or turned off. The process of
turning genes on and off is known as gene regulation. Gene
regulation is an important part of normal development. Genes are
turned on and off in different patterns during development to make
a brain cell look and act different from a liver cell or a muscle
cell, for example. Gene regulation also allows cells to react
quickly to changes in their environments. Although we know that the
regulation of genes is critical for life, this complex process is
not yet fully understood.
Gene regulation can occur at any point during gene expression,
but most commonly occurs at the level of transcription (when the
information in a genes DNA is transferred to mRNA). Signals from
the environment or from other cells activate proteins called
transcription factors. These proteins bind to regulatory regions of
a gene and increase or decrease the level of transcription. By
controlling the level of transcription, this process can determine
the amount of protein product that is made by a gene at any given
time.
Epigenetic marks can be inherited, understand why this
underscores an interactionist view of development
Epigeneticinheritance is the transmittance of information from
one generation to the next that affects the traits of offspring
without alteration of theprimary structureofDNA(i.e., the sequence
of nucleotides) or from environmental cues. The term "epigenetic
inheritance" is used to describe both cellcell and organismorganism
information transfer, whiletransgenerational epigeneticstypically
refers only to the latter. Although these two levels of epigenetic
inheritance are equivalent in unicellular organisms, they may have
distinct mechanisms and evolutionary distinctions in multicellular
organisms.
Genetically identical mice with different DNA methylation
patterns causing kinks in the tail of one but not the other.[1]Four
general categories of epigenetic modification are known:[2]1.
self-sustaining metabolic loops, in which amRNAorproteinproduct of
a gene stimulatestranscriptionof the gene; e.g.Wor1gene inCandida
albicans[3]2. structural templating in which structures are
replicated using a template or scaffold structure on the parent;
e.g.prions, proteins that replicate by changing the structure of
normal proteins to match their own
3. chromatinmarks, in which methyl or acetyl groups bind to
DNAnucleotidesorhistonesthereby altering gene expression patterns;
e.g.Lcycgene inLinaria vulgarisdescribed below
4. RNA silencing, in which small RNA strands interfere (RNAi)
with the transcription of DNA or translation of mRNA; known only
from a few studies, mostly inCaenorhabditis elegans[4]For some
epigenetically influenced traits, the epigenetic marks can be
induced by the environment and some marks are heritable, leading
some to view epigenetics as a relaxation of the rejection ofsoft
inheritanceof acquired characteristics.
EPIGENETICS AND INHERITANCE
We used to think that a new embryo's epigenome was completely
erased and rebuilt from scratch. But this isn't completely true.
Some epigenetic tags remain in place as genetic information passes
from generation to generation, a process called epigenetic
inheritance.
Epigenetic inheritance is an unconventional finding. It goes
against the idea that inheritance happens only through the DNA code
that passes from parent to offspring. It means that a parent's
experiences, in the form of epigenetic tags, can be passed down to
future generations.
As unconventional as it may be, there is little doubt that
epigenetic inheritance is real. In fact, it explains some strange
patterns of inheritance geneticists have been puzzling over for
decades.
Overcoming the Reprogramming Barrier
Most complex organisms develop from specialized reproductive
cells (eggs and sperm in animals). Two reproductive cells meet,
then they grow and divide to form every type of cell in the adult
organism. In order for this process to occur, the epigenome must be
erased through a process called "reprogramming."
Reprogramming is important because eggs and sperm develop from
specialized cells with stable gene expression profiles. In other
words, their genetic information is marked with epigenetic tags.
Before the new organism can grow into a healthy embryo, the
epigenetic tags must be erased.
At certain times during development (the timing varies among
species), specialized cellular machinery scours the genome and
erases its epigenetic tags in order to return the cells to a
genetic "blank slate." Yet, for a small minority of genes,
epigenetic tags make it through this process and pass unchanged
from parent to offspring.
Reprogramming resets the epigenome of the early embryo so that
it can form every type of cell in the body. In order to pass to the
next generation, epigenetic tags must avoid being erased during
reprogramming.
Inheritance Is Not Just about the GenesTraditional genetics goes
far in explaining how unique biological traits are passed on from
parents to children. DNA from each parent mixes together in a child
and this DNA contains discrete stretches of coded
instructionsgenesthat are used to make all the proteins we are made
of. A child is basically a mixed amalgam of proteins half from the
genes of each parent. However, biology is rarely so neat. Genes
only provide the bits of information that make an organism. Like
words that make up a story, genes need to be used at the right
place and right time to produce a meaningful result. Context is key
and cells have several controls to activate and shut down genes at
the right times as needed.
Sometimes genes are not just turned on or off temporarily but
more permanently shut down, folded up, and put in a type of
long-term storage. The controls that shut down, and occasionally
resuscitate genes, are "epigenetic controls" meaning "over and
above the genes." Recently, it has been discovered that some of the
epigenetic patterns of shut down and reactivated genes can be
passed from parents to children. This idea of epigenetic
inheritance has lead to general reevaluation of how inheritance
works and whether some traits, especially those associated with
certain life experience and environmental diseases, can be passed
from generation to generation.
Why Is Epigenetic Inheritance Important?It is the observation
that the patterns of genes that are shut down or activated in
response to our experience, combined with the discovery that gene
expression patterns can be passed on to our children, that makes
epigenetics so interesting. These two observations suggest the
surprising conclusion that our life experience may be able to
affect intrinsic inherited traits we pass on to our children. First
seen in bacteria and individual cells where certain "learned"
responses to chemicals in the environment were passed to their
progeny. Now, it seems that individuals may also inherent certain
traits based on their parents or grandparents experience.
According to classical genetics, although we are each the result
of an interaction of our genes and our environment, the way we live
shouldn't directly affect the genetic traits passed to our
children. The understanding derived from Darwinian evolution is
that we pass on one fresh unmarked variant of each of our
approximately twenty three thousand genes to our progeny. Except in
the extreme sense where there is physical DNA damage from toxics or
radiation, our environment or life experience should not alter the
basic characteristics of these genes. The idea that inheritable
gene changes occur in response to our environment or experience was
abandoned almost as soon as it was first proposed byLaMarck(a rival
of Darwin). However, it appears that Lamarck may have been at least
little right and we may, in fact, pass on genes that are marked up
based on our own experience.
Examples of Epigenetic InheritanceThere are very clear examples
of epigenetic inheritance in lower animals. Fruit flies exposed to
certain chemicals have baby flies with bristly outgrowths on their
eyes. More interesting examples in higher animals, though, suggest
how life experiences may shape the genetic deck of cards children
receive. For example, with rats, it has been shown that stressed
mothers have more anxious rat babiesthe hormonal difference and
anxious behaviors can be reliably measured in the progeny through
adulthood. Although this tendency can be explained by nurture, it
turns out that, even when the rat babies are transferred to a less
stressful environment with an unstressed adoptive mother, the
progenystill grow up just as apprehensive. It seems the genetics
have been reprogrammed as a result of the mother's experience. In
another example, researchers found that, in an isolated community
in Northern Sweden, people whose parents and grandparents gorged
themselves through a few rare years when an overabundant amount of
food was available havemuch shorter livesthan people whose
ancestors consistently struggled to get enough to eat and
occasionally were near starvation due to crop failures.
Although not as well established as the studies above, there is
also some evidence to suggest that the tendency forsome
psychological disorders to run in familiesmay be a result of
epigenetic inheritance and some researchers even go so far as to
suggest thatsome lifestyle behaviors or habits may develop into
inheritable traits. While a few of these conclusions may be far
reaching based on current data, there does seem to be a strong link
betweenhealth, including metal health, and epigenetic changesin
DNA. This observation has made epigenetics a very hot topic in many
areas of medical research.
understand that risk and protective factors are negative and
positive life ingredients that influence development and be able to
identify them in case examples; understand that they are
probabilistic, not deterministicChapter 4Risk and Protective
Factors
Neglect occurs to children of all races, socio-economic classes,
religions, family structures, and communities. However, there are
some factors that appear to make children more or less likely to be
neglected. Having one or more risk factors does not necessarily
mean that a child will be neglected; families and children react to
personal and societal factors differently. But they are warning
signs, nevertheless.
One or two major risk factors for neglect may have little effect
on a child's development, but having three or more risk factors
exponentially increases the potential for developmental problems.
Risk factors may be cumulative so that the more risk factors a
child or family is exposed to over the course of the child's
development, the greater the potential for problems to arise.98The
risk and protective factors in a child or family's life also may
interact with each other.Exhibit 4-1provides a conceptual model of
the interplay of various risk and protective factors related to
child neglect.
An instance of possible neglect may be related to one or more
contributing factors. For example, if a child is exposed to lead
paint in the home, there may be many contributing factors to the
neglect. The parent may be unwilling or unable to move to a home
where lead paint is not present, the landlord may be unwilling to
remove the lead paint from the walls, the city may not have an
adequate lead abatement program, or the community may not have
placed enough emphasis on making sure that low-income housing is
safe.99The caseworker would need to assess the situation to
determine if this is a case of neglect by the parent.
Child welfare professionals and others who interact regularly
with children and families should be able to recognize risk factors
so that they can identify situations where neglect is likely and
determine the most effective interventions. This chapter highlights
several types of risk and protective factorsenvironmental, family,
parent or caregiver, and childfor neglect.
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Environmental Factors
Neglectful families do not exist in a vacuum; numerous
environmental factors can contribute to child neglect. Some of
these include poverty, community and society characteristics, and
access to social supports. These factors may be interrelated (e.g.,
families who are poor often live in high-risk or unsafe communities
or lack social supportsD-link
Poverty
The level of child well-being in a State is strongly associated
with its rate of child poverty.100While child poverty has declined
over the past decade, it currently stands at 17.6
percent.101Compared to other types of child maltreatment, neglect
is more directly associated with poverty.102Of course, most poor
people do not neglect or otherwise maltreat their children, but
poverty, when combined with other risk factors, such as substance
abuse, social isolation, financial uncertainty, continual family
chaos, or a lack of available transportation and affordable child
care can put a child at greater risk for neglect.104Another study
found that within an economically disadvantaged sample, particular
aspects of poverty are more strongly correlated with physical
neglect reports than others.105For example, theperceptionby the
caregiver of economic hardship was positively correlated with child
neglect, even more than actual variations in household incomes.
Therefore, self-reports of economic hardship may be an important
signal for engaging in interventions with families to prevent
subsequent neglect. In contrast, employment had an inverse
relationship to reports of physical neglect. No difference existed
between income groups for rates of fatal injury or emotional
neglect.106It is important to note that many poor families are well
adjusted and competent; they have healthy marriages and do not
express their stress in violent or otherwise hurtful ways. Many
children who live in poverty are able to perform well in school,
are socially well-adjusted, do not engage in illegal activities,
and are not poor as adults. These children may have protective
factors, such as affectionate parents, high self-esteem, or a role
model, that help them to achieve these positive outcomes.107As
discussed inChapter 2,Definition and Scope of Neglect, many States
include an exception for poverty in their definitions of neglect.
There is usually a distinction between a caregiver's inability to
provide the needed care based on the lack of financial resources
and a caregiver's knowing reluctance or refusal to provide care,
even though the initial effect on the child is the same.108For
example, a family may not be able to afford food for their
children; therefore, their children's basic nutritional needs will
not be met. If the parents do not know about food assistance, they
would not be considered neglectful, but if they have been told
about a food assistance program and failed to use it, they may be
guilty of neglect.
Risk & Protective Factors
Research has shown that there are a variety of factors that
influence whether or not a young person will struggle with problems
such as underage drinking, drug abuse, delinquency or violent
behavior. Risk factors may increase the probability that a youth
will engage in such risky behaviors. Protective factors, on the
other hand, may decrease the probability a youth will engage in
risky and unhealthy behaviors.
Both risk factors and protective factors are complex and
cumulative. Their impact on a persons future behavior depends on
how many risk or protective factors occur at the same time, how
intense they are and how long they persist.
For example, having positive relationships with caring adults is
a powerful protective factors for youth in avoiding a variety of
risky and unhealthy behaviors. A strong relationship with an adult
role model over a number of years will have a more protective
impact than a positive, but short-term, connection with the same
adult over the course of a single event (e.g. a guest speaker at a
school assembly).
While a child may be exposed to certain risk factors over his or
her whole life (such as the negative impact of growing up in a poor
neighborhood), the negative influence of such risk factors may be
lessened by other protective factors such as a structured and
nurturing home environment, and a connection to religious or
community groups.
know what a turning point is and the common reasons for positive
turning points in peoples lives ??? STILL DONT KNOW
know the list of things that matter for development from
lecture; understand the concept of linked lives
Both in Notebook
know that we develop all our major organ systems and limbs in
the first 2 months of our gestational life (embryonic phase)The
embryonic period comprises thefirst 8 weeksof pregnancy. It is
divided into apreembryonic phase(from the 1rst to the 3rd week), in
which the three germinal layers arise, and into theembryonic
phaseproper (from the 4th to 8th week), in which the embryonic
organ anlagen arise.Development takes place thanks to
thegeneticprogram andenvironmentalfactors that are precisely tuned
to each other.
During the embryonic periodthe risk of congenital
abnormalitiesis the greatest. Before, spontaneous miscarriages
mostly occur. Later, the frequency of abnormalities and their
effects are smaller.The most important teratogenic factors
areinfectious diseases,chemical substances, medications,
andionizing radiation.
know how tobacco, alcohol & other drug use by mothers and
fathers affect pre- and post-natal development; know that there is
no safe level of alcohol during pregnancy or safe phase of
pregnancy in which to drinkThe lives of millions of children are
touched by substance use disorders (SUDs). The 2007 National Survey
on Drug Use and Health reports that 8.3 million children live with
at least one parent who abused or was dependent on alcohol or an
illicit drug during the past year. This includes 13.9 percent of
children aged 2 years or younger, 13.6 percent of children aged 3
to 5 years, 12.0 percent of children aged 6 to 11 years, and 9.9
percent of youths aged 12 to 17 years.48These children are at
increased risk for abuse or neglect, as well as physical, academic,
social, and emotional problems.49A predictable, consistent
environment, coupled with positive caregiver relationships, is
critical for normal emotional development of children. Parental
substance abuse and dependence have a negative impact on the
physical and emotional well-being of children and can cause home
environments to become chaotic and unpredictable, leading to child
maltreatment. The children's physical and emotional needs often
take a back seat to their parents' activities related to obtaining,
using, or recovering from the use of drugs and alcohol.50This
chapter discusses how prenatal and postnatal substance use by
parents affects fetal and early childhood development. It is
intended to help child protective services (CPS) caseworkers
understand the behaviors and problems that some children in the
child welfare system may exhibit and that hold implications for
their potential need for services.
A Definition of Child Maltreatment
The Child Abuse Prevention and Treatment Act, reauthorized in
the Keeping Children and Families Safe Act of 2003 (P.L. 108-36),
provides the minimum standards for defining child physical abuse,
neglect, and sexual abuse that States must incorporate into their
statutory definitions in order to receive Federal funds. Under this
Act, child maltreatment is defined as:
"Any recent act or failure to act on the part of a parent or
caregiver, which results in death, serious physical or emotional
harm, sexual abuse or exploitation, or an act or failure to act
which presents an imminent risk of serious harm."51A "child" under
this definition generally means a person younger than age 18 or who
is not an emancipated minor. In cases of child sexual abuse, a
"child" is one who has not attained the age of 18 or the age
specified by the child protection law of the State in which the
child resides, whichever is younger.52
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The Impact on Prenatal Development
In 2006 and 2007, an average of 5.2 percent of pregnant women
aged 15 to 44 years used an illicit drug during the month prior to
being surveyed, and 11.6 percent had consumed alcohol.53Nationwide,
between 550,000 and 750,000 children are born each year after
prenatal exposure to drugs or alcohol.54These children often are
medically fragile or born with a low birth weight. Some are born
prematurely and require intensive care.
Identifying the effects of drugs and alcohol on fetuses has
posed challenges for researchers. While there has been some success
researching the effects of alcohol on fetal development, securing
accurate information regarding the use of illicit drugs from
pregnant women or women who have given birth has proven to be very
difficult. In addition, women who abuse substances often have other
risk factors in their lives (e.g., a lack of prenatal care, poor
nutrition, stress, violence, poor social support) that can
contribute significantly to problematic pregnancies and births.
The sections that follow summarize some of what is known about
the effects of substance use on prenatal development.
know the risks that STIs pose to infantsWhat Effects Can STDs
Have on My Baby?
Different STDs pose different health risks for pregnant women
and their babies. Here is a list of some of the more common STDs
and the threats they pose to a healthy pregnancy:
Herpes/Genital Herpes:Herpesis one of the most common STDs a
pregnant woman can be infected with; fortunately, however, herpes
do not pose any major risks to a developing fetus. However, any
lesions that are exposed near the vaginal opening during delivery
could cause the disease to be passed on to the infant. That is why
many women with herpes or other genital warts choose to deliver via
a cesarean section.
Chlamydia:For mothers affected by chlamydia, you should be aware
that you are at an increased risk of miscarriage and preterm
delivery. Furthermore, if the baby is exposed to the disease during
delivery, he or she could be at risk for eye infections or
pneumonia.
HPV:Genital warts resulting from HPV usually take the form of
itchy cauliflower-like clusters. These warts may enlarge during
pregnancy due to hormones. Unlike some other STDs, treatment for
HPV will likely be postponed until after giving birth. If the warts
are large enough, however, they could present an obstacle to
delivery, resulting in a cesarean section.
Syphilis:Because syphilis is a viral infection, it can be easily
passed along from mother to child, which can pose a variety of very
serious risks including fatality. Babies that do survive are often
born prematurely and tend to have birth defects affecting their
brain, eyes, ears, skin, heart and bones.
Gonorrhea:If gonorrhea is contracted during pregnancy it will
likely become noticeable in the form of vaginal discharge and a
burning sensation during urination. Left untreated, pregnant women
with gonorrhea are at an increased risk of miscarriage and
premature birth. If the infection is present at the time of birth
the baby may be born blind, or with a joint or blood infection.
HIV/AIDS:Due to recent medical advancements in HIV/AIDS
research, transmission of HIV/AIDS from mother to child has become
almost completely preventable. That said, without treatment it is
likely the baby will be born with the virus.
Hepatitis B:Hepatitis B is disease that affects the liver, and
as such it can be passed to the baby through the placenta during
pregnancy as well as childbirth. Women with hepatitis B are also
more likely to give birth prematurely. With screening and vaccines
now available, however, it is hoped that the disease will soon
become a thing of the past.
Trichomoniasis:Symptoms of trichomoniasis include yellowish
vaginal discharge and painful sex and urination. Having this STD
during pregnancy can increase your risk of preterm birth and, more
rarely, cause the newborn to contract the disease during
delivery.Other harmful effects of STDs in babies may include
stillbirth, neurological damage (such as brain damage or lack of
coordination in body movements), deafness, acute hepatitis,
meningitis, and chronic liver disease.
How Can STDs be Treated During Pregnancy?
Treatment for STDs generally includes a combination of
medications, including antiviral pills and antibiotics. Treatment
is especially promising for bacterial infections such as herpes,
gonorrhea, syphilis and Chlamydia, as these can almost always be
cured through the use of antibiotics. Recently, natural cures for
herpes have become popular as well.
Certain diseases may require postponed treatment due to possible
risks treatment may pose to the fetus, as is the case for HPV
(genital warts).
But as is the case with any STD, the best treatment is
prevention, so be sure to undergo routine screening for STDs and
always practice safe sex. For more information on STDs, check out
thisguideprovided byepigee.org.
know what Rene Spitz found re: infants and toddlers who were fed
and housed, but not given any nurturance/close human contact and
holdingknow that infants/toddlers form attachments to both mothers
and fathers; know that we form attachments to various close others
across our lifespan; understand that our sense of attachment,
secure or insecure/avoidant, both reflects the realities of a
particular relationship and influences the quality of our (usually
future) close relationships (as well as influencing a range of
other long-term outcomes)Attachment is the emotional bond of infant
to parent or caregiver. It is described as apattern of emotional
and behavioural interactionthat develops over time, especially in
contexts where infants express a need for attention, comfort,
support or security. Parents ability to perceive, interpret and
react promptly to their infants needs and attention, in turn
influence thequality of their attachment relationships. Based on
Bowlbys attachment theory, the relationship developed with primary
caregivers is the most influential in childrens lives. A secure
relationship fosters not onlypositive developmental outcomesover
time, but also influences the quality of future relationships with
peers and partners.
Secure parent-child relationships help children to a) regulate
their emotion in stressful situations, b) explore their environment
with confidence, and c) foster their cognitive, emotional and
language development. Furthermore, children who are securely
attached are predisposed to display positive social behaviours
(e.g., empathy and cooperative behaviours) helping them todevelop
future positive relationships. On the other hand, insecure and
disorganized attachment put children at increasing risk ofproblem
behaviours and psychopathologies. Examples include preschool and
school-aged aggression, depression and emotional dysregulation.
So far, we have seen that there is a link between the quality of
infant attachment and the quality of care an infant receives during
the first year of life. Although interesting, this research would
be less important if the effects applied only to the first year.
They do not. Alan Sroufe, a psychologist at the University of
Minnesota, and his colleagues continue to report on a longitudinal
study of a large group of low-income families who were originally
recruited in Minneapolis in the early 1970s (Sroufe, Egeland,
Carlson, & Collins, 2005). Researchers observed these families'
infants with their mothers in the Strange Situation when the
infants were 12 and 18 months of age, and they then collected
information on these children as they grew older. During the
preschool years, teachers and observers rated children who had been
securely attached as infants as happier and more socially skilled,
competent, compliant, and empathetic than children who were
insecurely attached as infants. Preschoolers with secure
attachments also were more popular with their peers, had higher
self-esteem, and were less dependent and negative.
By age 10 years, children in the securely attached
classification were still less dependent and received higher
ratings on self-esteem, self-confidence, social skills, and
emotional health. They made more friends than did children who had
been insecurely attached as infants, and they spent more time with
their friends.
Adolesce