The structure of communication networks is an important determinant of the
capacity of teams, organizations and societies to solve policy, business and
science problems. Yet, previous studies reached contradictory results about the
relationship between network structure and performance, finding support for the
superiority of both well-connected efficient and poorly connected inefficient
network structures. Here we argue that understanding how communication networks
affect group performance requires taking into consideration the social learning
strategies of individual team members. We show that efficient networks
outperform inefficient networks when individuals rely on conformity by copying
the most frequent solution among their contacts. However, inefficient networks
are superior when individuals follow the best member by copying the group
member with the highest payoff. In addition, groups relying on conformity based
on a small sample of others excel at complex tasks, while groups following the
best member achieve greatest performance for simple tasks. Our findings
reconcile contradictory results in the literature and have broad implications
for the study of social learning across disciplines