Signaling benefits of partner choice decisions.

When deciding whom to choose for a cooperative interaction, two features of prospective partners are especially relevant: ability to provide benefits, and willingness to provide those benefits. Often, these traits are correlated. But, when ability and willingness are in conflict, people often indicate that they value willingness over ability, even when doing so results in immediate losses. Why would such behavior be favored by natural selection acting at the level of the individual? Across nine experimental studies (seven preregistered) and a mathematical model we explore one way of explaining this costly choice, demonstrating that choosing a willing over an able partner affords one a moral reputation and makes one more likely to be chosen as a cooperation partner. In fact, even people who choose an able over a willing partner for themselves prefer others who choose a willing over an able partner. Crucial to our model, we find that valuing willingness over ability is an honest signal of both higher levels of generosity in an economic game and lower levels of trait Machiavellianism. These findings provide the first extensive exploration of the signaling benefits of partner choice decisions. Furthermore, this work provides one explanation for why we choose those who are willing over those who are able, even at a cost to ourselves: By doing so, we in turn look like good potential partners. (PsycInfo Database Record (c) 2022 APA, all rights reserved).