Why did the Hutu and Tutsi tribes fight? Why is the Cheyenne tribe important to understanding Native American history? Why was the American Indian Movement important? Why is Wounded Knee remembered by the Lakota tribe? Why did the Lakota reside in the Northwest?
When the Hutu's killed the Tutsi's in Rwanda, they vastly enjoyed themselves. They were happy; it's one mode of human collective action. That sort of happiness will be on the upswing, and it may not be dysfunctional from a biological standpoint. But hey, it's the pursuit of happiness...