Women and Men React Differently to Infidelity, Study Shows.

A Norwegian study from the Norwegian University of Science and Technology, involving over 1,000 participants and published in Personality and Individual Differences (November 2015), reveals stark gender differences in jealousy triggers, with men most distressed by sexual infidelity and women by emotional infidelity, despite Norway’s high gender equality. Conducted by Associate Professor Mons Bendixen, Professor Leif Edward Ottesen Kennair, and Professor David Buss, the research contrasts cultural gender role theories—suggesting equality minimizes differences—with evolutionary psychology, which attributes these reactions to reproductive challenges over generations. Men’s jealousy, linked to paternity uncertainty, drives monitoring of sexual infidelity, while women, assured of maternity, react to emotional infidelity threatening resource investment from partners. Using both forced-choice and continuous-measure questionnaires, the study found consistent sex differences unaffected by prior infidelity experiences or relationship status, supporting an evolved psychological mechanism over learned behavior. This persists in a society with strong paternal involvement, highlighting deep-rooted evolutionary influences on jealousy.