Evolution & Human Behavior
Humans form and maintain friendships across long distances, which can provide access to non-local resources and support against large shocks that affect the entire local community. However, there may be a greater risk of free-riding in long-distance friendships, as monitoring for defection is more difficult at greater distances; accordingly, help between long-distance friends may be more explicitly contingent than between close-distance friends. We interviewed 918 participants from 21 fishing villages in Tanzania about whether they had received help in the form of a gift or loan from a friend living in their village and a friend living in a neighboring village. As there are local expectations that loans will be repaid but gifts will not, we predicted that close-distance friends would be more likely to help with gifts, whereas long-distance friends would be more likely to help with loans. Contrary to our predictions, gifts and loans between close- and long-distance friends were similar in kind and amount, though close-distance friends provided help more frequently, possibly because close-distance friends are more likely to meet frequently and belong to the same religious congregation. These results indicate that long-distance friendships are an important, and likely robust, strategy for managing risk and accessing more resources.