Birds of
a
Feather,
or Friend of a Friend? Using Exponential Random Graph Models
Investigate
Adolescent Social Networks
by Steven M. Goodreau, James A. Kitts, and Martina Morris
Forthcoming in Demography.
Click to Download Final Draft of Paper
ABSTRACT
This paper uses
newly
developed statistical methods to examine the generative processes
that
give rise to wide-spread patterns in friendship networks.
The
methods incorporate both traditional demographic measures on
individuals (age, sex, and race) and network measures for
structural
processes operating on individual, dyadic, and triadic
levels. We
apply the methods to the adolescent friendship networks in
fifty-nine
US schools from the National Longitudinal Survey of Adolescent
Health
(Add Health). We model friendship formation as a selection
process constrained by individuals’ sociality (propensity to make
friends), selective mixing in dyads (friendships within race,
grade, or
sex categories are more likely), and closure in triads (a friend’s
friends are more likely to become friends), given local population
composition. Whites and Blacks are the most consistently
cohesive
racial categories and, when Whites are in the minority, they
display
stronger selective mixing than do Blacks when Blacks are in the
minority. Hispanics exhibit disassortative selective mixing
under
certain circumstances; in other cases they exhibit assortative
mixing
but lack the higher-order cohesion common in other groups. Grades
are
always highly cohesive, while females form triangles more than
males. We conclude with a discussion of how network analysis
may
contribute to our understanding of sociodemographic structure and
the
processes that create it.