highly significantp<0.001
Age difference remained a highly significant predictor of aggression (p<0.001).
Age difference remained a highly significant predictor of aggression (p<0.001).
Interactions between relatedness categories and sex makeup weakened and were no longer significant (for play: P =0.555; for grooming: p=0.243); sex category×age difference interactions remained highly significant for grooming (p<0.001) and were marginally significant for play (p=0.070).