Roommate's race and the racial composition of white college students' ego networks.

We develop and test a new hypothesis about how the race of a college freshman's roommate affects the racial composition of the student's ego network. Together, three principles of social structure-proximity, homophily, and transitivity-logically imply that college students assigned a roommate of a given race will have more friends (other than their roommate) of that race than will students assigned a roommate not of that race. A test with data collected from 195 white freshmen at Stanford University in the spring of 2002 supports this prediction. Our analysis advances earlier work by predicting and providing evidence of race-specific effects: While students assigned a different-race roommate of a given race have more friends (other than their roommate) of their roommate's race, they do not have more different-race friends not of their roommate's race.