Do "Birds of a Feather Flock Together?" Gender Differences in Decision-making Homophily of Friendships

Homophily the tendency of individuals to associate with others who are similar is considered as a key determinant of friendships. Most studies focus on the homophily of friendships as measured by demographic characteristics. In this paper, we explore patterns of homophily as measured by risk preferences and social preferences, both of which are elicited from a large-scale laboratory experiment. Our focus is on gender differences in homophily, which are examined by testing for behavioral gaps in friendship formation within a pair of same-gender friends in a series of decision-making tasks. We find significant gender differences in homophily: among males, friendship appears along with similar patterns in social decision-making, while females are more likely to become friends with those who exhibit different patterns of decision-making. Our findings are consistent across various robustness checks. We conclude by proposing potential explanations for these gender differences.