“Three is better than two”: The Attraction effect in donation decisions

Three experiments (N=1,207 total) tested the attraction effect in the context of helping behavior. Participants could donate by choosing one alternative in a set of either two or three alternatives. The three alternatives set included a decoy - an alternative that resembled, but was clearly inferior to, a target (i.e., the most beneficial) alternative. In line with the attraction effect, we found that people chose the target alternative more often when the decoy was included to the set. We further suggest that the perceived benefits of the donation mediate this effect. Specifically, we found that adding a decoy increased the extent to which the target alternative is perceived as beneficial to the needy, which in turn increased its choice share. Importantly, our results are robust to the order of presentation of the alternatives, and extended to ecological settings in which participants could refuse to help at all, or could donate any amount they wanted.