Although prior research has examined the relationship between genetic relatedness and helping behavior (Burnstein, Crandall, and Kitayama, 1994), less is known about its role in aggressive responses to insults ( Fitzgerald and Ketterer, 2011 ).Drawing on inclusive fitness theory ( Hamilton, 1964 ) and the Kinship, Acceptance, and Rejection Model of Altruism and Aggression (KARMAA; Webster, Drain Outlet Hose 2008 ; Webster et al., 2012 ), we designed a 2 (participant gender) × 2 (target gender) × 2 (insult: status vs.reproductive) × 3 (relatedness: stranger vs.
cousin vs.sibling) between-person experiment in which 489 participants (a) read vignettes in which a stranger, cousin, or sibling was insulted Supplements - Juice and (b) reported their emotional reaction and retaliation likelihood (six-item α=.91) in response to the insult.Consistent with theory and prior research, men were significantly more aggressive than women, and people were significantly more aggressive responding to insults against kin than non-kin.
These findings support theoretically-derived, dynamic, and domain-specific links among insults, gender, relatedness, and aggression.