homophily

Homophily: The extent to which actors form ties with similar versus dissimilar others.

Homophily (i.e., "love of the same") is the tendency of individuals to associate and bond with similar others.

Birds of a Feather: Homophily in Social Networks.

Researchers at M.I.T. even published "Homophily in Online Dating: When Do You Like Someone Like Yourself?"

This dilemma has been considered by Aguiar and Parravano in Tolerating the Intolerant: Homophily, Intolerance, and Segregation in Social Balanced Networks, modeling a community of individuals whose relationships are governed by a modified form of the Heider balance theory.

"Similarity breeds connection," the sociologists Miller McPherson, Lynn Smith-Lovin and James Cook wrote in their classic 2001 paper on the subject, "Birds of a Feather: Homophily in Social Networks," and "the result is that people's personal networks are homogeneous."

In "Homophily in Social Software," Nat Torkington, a trend spotter for O'Reilly Media, argued that "homophily raises the question for social-software designers of how much they should encourage homophily and how much they want to mix it up."