Coalitional mate retention is correlated positively with friendship quality involving women, but negatively with male–male friendship quality

Friendship solved adaptive problems over human evolutionary history, including cooperative hunting and alloparenting. Pham, Barbaro, and Shackelford (in press) investigated another potential function of friendship: the provision of coalitional mate retention, whereby individuals ask an ally to assist with thwarting their romantic partner’s infidelity. In the current research, 387 participants (176 women) reported how often they requested or received coalitional mate retention from a male friend and from a female friend and reported on the quality of each friendship. The results indicate that the deployment of coalitional mate retention is positively associated with the quality of friendships with women (female–female friendships, male–female friendships, female–male friendships), but negatively associated with the quality of male–male friendships.