Culture and Mobility Determine the Importance of Similarity in Friendship

We test whether the ability to start friendships-and end them-determines what we look for in friends. We hypothesized that individual differences in beliefs about relationship choice would translate into differences in similarity of relationship partners. To test the constructs across their spectrum, we sampled both American and Korean relationships (N = 1,603). Study 1 field-sampled naturally occurring relationship pairs in the United States and Korea; independent self-construal was positively correlated with relational mobility and similarity within relationship pairs. Using the entire data set, relational mobility was positively correlated with similarity, but the two were negatively correlated within nations. Study 2 identified two components of relational mobility, entry and exit. Easy entry to relationships correlated with high importance of similarity; easy exit from relationships correlated with low importance of similarity. An experiment (Study 3) manipulating both ease of entry to and exit from friendship found the belief that people are relatively free to end an unsatisfying friendship reduced the importance of similarity for friendship selection.