Psychology 3051 Psychology 305A: Theories of Personality Lecture 8 1.

Psychology 305 1

Psychology 305A: Theories of Personality

Lecture 8

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Scoring Your Questionnaire: BAS/BIS

1. Reverse score items 10 and 19.

2. Sum the following items:

• 1, 4, 7, 10, 12, 15, 19 • 2, 3, 5, 6, 8 • 9, 11, 13, 18 • 14, 16, 17, 20

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Announcements

1. The meetings for the Peer Learning Community (PLC) for Psychology 305A will be held on:

Mondays, 4:00-5:00 PMThursdays, 4:00-5:00 PM

in room 2563 of the Kenny Building. Please see the e-mail circulated to PLC members on October 4th.

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2. There has been a delay in the posting of the grades for the first exam due to an error in the processing of the multiple choice responses by the scantron machine.

I will post the grades when I receive them from the Teaching Assistants and notify the class via e-mail.

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The Biological Perspective

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1. What are heritability and environmentality and how are they assessed? (continued)

2. What personality characteristics are heritable?

3. Who was Phineas Gage?

1. contrast adoption studies and twin studies.

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By the end of today’s class, you should be able to:

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2. discuss the shortcomings of adoption studies and twin studies.

3. identify distinct temperaments and discuss their heritability.

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5. discuss the heritability of diverse personality characteristics.

4. distinguish between antisocial personality disorder and psychopathy.

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• Heritability and environmentality are assessed using 2 methods:

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What are heritability and environmentality and how are they assessed? (continued)

1. Adoption Studies

Examine whether adopted children are more similar to their biological parents than their adoptive

parents with respect to a given characteristic.

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For a given personality characteristic, two correlations are calculated:

r2: The correlation between participants’ scores and the scores of their adoptive parents on the characteristic (reflects the influence of shared environment).

r1 > r2 indicates that the personality characteristic is heritable.

r1: The correlation between participants’ scores and the scores of their biological parents on the characteristic (reflects the influence of shared genes).

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2. Twin Studies

Examine whether monozygotic (MZ) twins are more similar than dizygotic (DZ) twins with respect to a given characteristic.

A more powerful means by which to assess heritability and environmentality.

MZ twins share 100% of the same genes; DZ twins share 50% of the same genes.

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For a given personality characteristic, two correlations are calculated:

r2: The correlation between DZ twins on the characteristic (reflects a small degree of genetic overlap).

r1 > r2 indicates that the personality characteristic is heritable.

r1: The correlation between MZ twins on the characteristic (reflects a large degree of genetic overlap).

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E.g., Dominance:

r1 = .57 (MZ twins)

r2 = .12 (DZ twins)

Heritability = 2 (r1–r2)

Environmentality = (1.00–heritability)

= 2 (.57–.12) = .90

= 1.00-.90 = .10

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What personality characteristics are heritable?

Temperaments

• Temperaments: Personality characteristics that appear during the 1st year of life, persist across the lifespan, have a pervasive influence on behaviour, and are highly heritable.

• Buss and Plomin (1984) identified 3 temperaments:

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1. Activity level: Degree to which an individual expends physical energy through motor activity (i.e., intensity of behaviour, speed of action).

2. Sociability: Degree to which an individual prefers to be with others rather than be alone.

3. Emotionality: Degree to which an individual becomes physiologically aroused in upsetting situations. Comprised of 3 components: anger, distress, and fear.

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EAS Temperament Survey

Score on items:

• 2, 7, 10, 17 = Activity Level

• 1, 6, 15, 20 = Sociability

• 5, 8, 13, 18 = Emotionality: Anger

• 4, 9, 11, 16 = Emotionality: Distress

• 3, 12, 14, 19 = Emotionality: Fear

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EAS Temperament Survey Means and Standard Deviations (Naerde et al., 2004), N = 939

Mean SD

Activity level 3.10 .69

Sociability 3.76 .60

Emotionality: Anger 2.94 .69

Emotionality: Distress 2.33 .72

Emotionality: Fear 2.22 .60

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• Heritability statistics (Wlodzimierz et al.,2003):

Activity level: .58

Sociability: .42

Emotionality—Anger: .62

Emotionality—Distress: .54

Emotionality—Fear: .70

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• Other temperaments proposed in the literature:

Effortful control/Impulsivity (e.g., Kochanska & Knaack, 2003).

Approach/avoidance (e.g., Rothbart et al., 2001; Eisenberg et al., 2004).

Intelligence (e.g., Plomin, 1989).

Behavioural inhibition (i.e., shyness; e.g., Kagan, 2011; Kagan & Snidman, 1991).

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The Big 5 Dimensions

• Heritability statistics (Jang et al., 1998; see also Yamagata et al., 2006):

Extraversion: .50

Agreeableness: .48

Conscientiousness: .49

Neuroticism: .49

Openness to Experience: .48

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Personality Disorders

• Heritability statistics (Coolidge et al., 2001):

Avoidant personality disorder: .61

Borderline personality disorder: .76

Histrionic personality disorder: .79

Narcissistic personality disorder: .66

Obsessive-compulsive personality disorder: .77

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• Hare Psychopathy Checklist-Revised (PCL-R)

Assesses 20 symptoms associated with psychopathy. Each symptom is scored from 0 – 2 (0 = definitely does not apply to the person, 2 = definitely does apply to the person).

Maximum score: 40. A score of 30 is indicative of the presence of psychopathy.

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Personality Characteristics Related to Psychopathy

Consists of 2 factors:

A. Affective/interpersonal features: Glibness/superficial charm, grandiose sense of self-worth, need for stimulation/proneness to boredom, pathological lying, manipulative, lack of remorse or guilt, shallow affect, callous/lack of empathy.

B. Behavioural features: Parasitic lifestyle, poor behavioural control, promiscuous sexual behaviour, early behaviour problems, lack of realistic long-term goals, impulsivity, irresponsibility, failure to accept responsibility for actions, juvenile delinquency, criminal versatility.

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• Heritability statistics (Blonigen et al., 2003; Bouchard et al., 1990; Tellegen et al., 1988):

Fearlessness ………………………………………… > .95

Carefree Nonplanfulness (i.e., impulsiveness)……... .94

Machiavellianism (i.e., enjoys manipulating others)... .74

Social potency (i.e., skilled at influencing others) …. .66

Aggressiveness ……………………………………….. .67

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• Heritability statistics (Bouchard et al., 1990; Tellegen et al., 1988)

Creativity or imagination ………………………..… .74

Sense of alienation ………………………….......... .59

Traditionalism ………………………………….…... .59

Low risk taking …………………………………….. .45

Achievement orientation …………………............. .38

Other Personality Characteristics

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Who was Phineas Gage?

• Phineas Gage was a 19th century rail worker involved in construction in Vermont.

• In 1848, an accidental explosion blew an iron rod through his head.

• The rod entered under his left cheek and passed through his frontal lobes, ultimately exiting through the top of his

head.

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The Skull of Phineas Gage, 1823 - 186026

Reconstruction of the Path of the Iron Rod Through Gage’s Skull

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• According to Gage's physician, Gage’s personality radically changed after the accident:

Gage was fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was “no longer Gage.” (Harlow, 1848)

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• Neurologist Antonio Damasio has written extensively on Gage. According to Damasio, Gage's story marks the historical beginnings of the scientific study of the physiological basis of personality.

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• Today, the study of the physiological basis of personality is a dominant area in personality psychology, reflecting a “biological revolution.”

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The Biological Perspective

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1. What are heritability and environmentality and how are they assessed? (continued)

2. What personality characteristics are heritable?

3. Who was Phineas Gage?