Distress in response to infidelity committed by the partners of close others: Siblings versus friends

Bohner G, Echterhoff G, Glaß C, Patrzek J, Lampridis E. Distress in response to infidelity committed by the partners of close others: Siblings versus friends. Social Psychology. 2010;41(4):223-229.To test rival explanations for sex differences in distress over sexual vs. emotional infidelity, evolutionary psychologists have studied people's reactions to the infidelity suffered by close relatives, claiming that sex-of-target effects would support an evolutionary explanation but refute a sociocultural explanation. This paradigm was extended by comparing genetically related and unrelated targets in two cultures. Students (N = 566) in Greece and Germany reported how much infidelity committed by the partners of siblings versus friends would distress them. Sex-of-target effects were found, though they were limited to Greek participants and to genetically unrelated targets. Across targets, a sex-of-participant effect emerged, with men being more distressed by sexual (vs. emotional) infidelity than women. The results are discussed with respect to evolutionary and sociocultural theorizing