  Social ties are the invisible glue that keeps together human ecosystems.
Despite the massive amount of research studying the role of social ties in
communities (groups, teams, etc.) and society at large, little attention has
been devoted to study their interplay with other human behavioral dynamics. Of
particular interest is the influence that social ties have on human performance
in collaborative team-based settings. Our research aims to elucidate the
influence of social ties on individual and team performance dynamics. We will
focus on a popular Multiplayer Online Battle Arena (MOBA) collaborative
team-based game, Defense of the Ancients 2 (Dota 2), a rich dataset with
millions of players and matches. Our research reveals that, when playing with
their friends, individuals are systematically more active in the game as
opposed to taking part in a team of strangers. However, we find that increased
activity does not homogeneously lead to an improvement in players' performance.
Despite being beneficial to low skill players, playing with friends negatively
affects performance of high skill players. Our findings shed light on the mixed
influence of social ties on performance, and can inform new perspectives on
virtual team management and on behavioral incentives.
