Helping Others to Find Long-Term and Short-Term Mates: A Test of Inclusive Fitness, Reciprocal Altruism, and Parental Investment Theories

Abstract

Individuals prefer helping some people more that others when it comes to finding a mate, and these preferences depend on whether long- or short-term mates are considered. Study 1 ( N = 108) examined three theoretical frameworks (inclusive fitness, reciprocal altruism, and parental investment) for understanding why individuals would be more willing to help some individuals find mates instead of others. College participants reported how willing they were to help different types of individuals (e.g., sister, stranger) find a mate. When considering willingness to help others find a long-term mate, people preferred kin over nonkin, supporting an inclusive fitness model. However, when considering willingness to help others find short-term mates, people preferred helping people their own age, supporting a reciprocal altruism model. Study 2 ( N = 143) replicated this age-cohort effect. Although rates of willingness to help others find mates were generally low, people were more likely to help others find a long-term mate than a short-term one.