Shadow Wolf
Certified People sTabber & Business Owner
I believe it is an evolved mechanism for social animals to aid in group cohesion. Social animals do not fare well on their own, while group living and cooperation greatly increases individual survival odds. And we see a sense of morality in general (including guilt and shame) in all human cultures, and we even see behaviors that suggest these things in other animals. Most dog owners, for example, know their dog's posture and demeanor changes when they have done something that upsets or angers us, knowing they did something wrong. We also see "time out" being used in bonobo troupes. And it works because isolation and rejection are painful and destructive to social animals.