SN- Lecture 9

Social Capital & Network Characteristics

Lecture 9

Aims Lecture 9To understand:

To study characteristics of networks

Networks as social capital

The problem of only a structuralist approach+

+

+Homophily

Reciprocity

Centrality

Some Questions

Social network research requires general theories to answer:

In Network Research

Some Questions


Can the effects of networks (i.e., on behavior) be generalized across situations?

In Network Research

a.

Some Questions


Can the effects of networks (i.e., on behavior) be generalized across situations?

In Network Research

a.

Why certain network effects sometimes occur and sometimes not?b.

and if not,

i.e., Why is there more clustering in some networks than in others?

Structure & Social Capital

Structuralism

Structure overrides preferences

A first approach

You can explain people’s actions by only knowing the structure of their social network

Claims:

+

+

Structuralism

Structure overrides preferences

A first approach

You can explain people’s actions by only knowing the structure of their social network

Claims:

+

+

Give me the network & I will tell you what the actors will do

Selling Point

Labor markets (Granovetter, 1974)

Of this perspective

Illegal services: Abortion (Lee, 1969)

All markets:

+

+

Are socially organized in networks

Selling Point


Of this perspective


All markets:

+

+


Role equivalence:Persons are tied not to the same persons but to similar persons

(Wasserman & Faust, 1994)

Selling Point


Of this perspective


All markets:

+

+


Role equivalence:Persons are tied not to the same persons but to similar persons

(Wasserman & Faust, 1994)

Two positions in the aggregate: an elite person (well-connected) & a hanger-on (not well-connected)

Main ProblemsOf structuralism

It lacks a theory of individual behavior

Main Problems

Think about the micro-macro link

Of structuralism


+

Main Problems


Of structuralism


+

Rational Choice Perspective:

Conceives networks as social resources

Main Problems


Of structuralism


+

Rational Choice Perspective:

Personal networks can be treated as social capital that is instrumental in reaching our goals

Conceives networks as social resources

Not a new ideaSince Hobbe’s Leviathan:

Not a new idea

Thomas HobbesEnglish philosopher1588-1679

To have friends is to have power: for they are strengths united

Since Hobbe’s Leviathan:

Networks as Social Capital

Networks are treated as a specific resource important for most goals people have in life.


Two main propositions in S.C. Theory





1 Social Resource Hypothesis: people better equipped with social capital will be better able to attain their goals




1 Social Resource Hypothesis: people better equipped with social capital will be better able to attain their goals

2 Investment Hypothesis: people will invest in social capital according to its instrumental value in producing their ends

Networks as S.C.It explains the emergence as well as the

effects of social networks



A person’s social capital promotes her goal achievement



She will invest in it depending on its instrumental value

&




Macro-micro link

She will invest in it depending on its instrumental value

&




Macro-micro link

She will invest in it depending on its instrumental valueMicro-macro link

&


Homophily

Practical 11Choose links & Actions

Homophily

If instead of just looking at the network

We keep track of characteristics of the nodes (i.e., attributes)

Lazarsfeld & Merton (1954)

Homophily



We tend to find that link nodes are similar to each other


Homophily



We tend to find that link nodes are similar to each other

Birds of a feather flock (will fly) together

Philemon Holland, 1960


Real-life networksHomophily

Race & friendship networks US:

Interracial marriages US:

Gender & friendship networks


Only 8% of people have any people of another race that they discuss important matters with (Marsden, 1987)







1% of white marriages, 5% of black marriages, 14% of asian marriages (Fryer, 2006)








Closest friends: 10% of men name a woman, 32% of women name a man (Verbrugge, 1977)







Closest friends: 10% of men name a woman, 32% of women name a man (Verbrugge, 1977)


In all cases lower than if ignoring attributes

Possible ExplanationsReasons for Homophily

Opportunity (Contact Theory):

Benefits/Costs:


The possibility that you meet people could be biased by attributes (i.e, race)


Benefits/Costs:

More of a chance of meeting your own type




Benefits/Costs:


Common attributes (i.e., language, culture, knowledge) make it easier




Benefits/Costs:

Also social pressure or social competition


Important:





Benefits/Costs:

Also social pressure or social competition



Important:

The structure of the network depends on the characteristics

i.e., why communication might circulate among one group and not another?

Quick Summarytwo points

From Structuralism:

From Homophily (Segregation Patterns):


From Structuralism:

The characteristics of the network matter. They affect the individuals



From Structuralism:

The characteristics of the network matter. They affect the individuals


The characteristics of the individuals matter. They affect the structure of the network

Reciprocity

ReciprocityLocal Patterns


Directed Networks


Directed Networks

A node can be linked to another without the second being linked to the first (i.e., webpages)


Directed Networks


ij in g does not imply ji in g


Directed Networks


Reciprocity

There is a tendency to dyadic reciprocation in most directed networks



Directed Networks


Reciprocity

There is a tendency to dyadic reciprocation in most directed networks


if ij in g it is more likely ji in g

ReciprocityExplanation


Mutual Dependence


Mutual DependenceActors (i.e., players, people) depend on each other for valued outcomes, and benefits will be received from another actor only if they are also given in return

(Emerson, 1972)



Think aboutCooperation: if relations are not reciprocated they are likely to be terminated more rapidly

(Emerson, 1972)



Think aboutCooperation: if relations are not reciprocated they are likely to be terminated more rapidly

(Emerson, 1972)

Keeping a non-reciprocated relation implies status deference

tend to be eliminated

Node Centrality

Node CentralityPositions in Networks


Who are influential, powerful (Think of our Facebook Example with Ana)

How different nodes are positioned in the network?




Many social networks show a fair extent of centralization




Many social networks show a fair extent of centralizationdifferentiation between social actors with

respect to their centrality

Node CentralityExample

Ways of measuring centrality

Node Centrality

2

1 4

1 24

1 3

3 2

3 2

2

2

Example


Node Centrality

2

1 4

1 24

1 3

3 2

3 2

2

2

Both white nodes have degree 2 (degree centrality)

The first seems more central - neighbors (3) & (4): (betweenness)

Better connected in another sense

Example


Node Centrality

2

1 4

1 24

1 3

3 2

3 2

2

2

There are many other measures of centrality

Both white nodes have degree 2 (degree centrality)

The first seems more central - neighbors (3) & (4): (betweeness)

Better connected in another sense

Example


Node CentralityWhy do we observe it?

It reflects social organization and opportunities


It reflects social organization and opportunitiesA strongly centralized network increases the likelihood of collective action in mobilizations - easier contact to others

(Marwell, Oliver & Prahl, 1988)


Result of feedback processesFavoring the creation of links to nodes that are already highly connected







Unto him that hath is given and from him that hath not is taken away, even that which he hath

The Matthew effect (Merton, 1968)





Unto him that hath is given and from him that hath not is taken away, even that which he hath

The Matthew effect (Merton, 1968)

However, centralization is most likely in physical networks: Internet hubs

Checklist

Both structure of the network & individual behavior (and characteristics) influence each other

Checklist


Checklist

People use their social networks as a form of capital that helps them achieve what they want

Checklist


Social networks portray different properties:


Checklist


Social networks portray different properties:

Individuals with common traits are likely to be related (Homophily)

Most relationships are reciprocal (both parts aim for it)

We can look locally at who is influential (centrality)Important for diffusion of information


Questions?

SN- Lecture 9

Technology

social capital networks

effects of networks

persons social capital

theory networks

structure social capital

social resources

personal networks

social network claims