Indeed, if females weren't unfaithful, why would male jealousy have evolved? And, that men so often are caring and giving suggests that cuckoldry hasn't been rampant. So, as men become better at detecting signs of infidelity, women should do one better by seeming more devoted. Says Wright: "It could be expedient for a married woman to not feel chronically concerned with sex, even if her unconscious is keeping track of prospects."
