хорошая статья -
http://www.nytimes.com/2011/07/05/science/05angier.html?_r=1&ref=science объясняет, например, почему палестинцы кидаются камнями -
Early humans also needed ways to control would-be bullies, and our exceptional pitching skills - which researchers speculate originally arose to help us ward off predators - probably helped. “We can throw much better than any other primate,” Dr. Wilson said, “and once we could throw things at a distance, all of a sudden the alpha male is vulnerable to being dispatched with stones. Stoning might have been one of our first adaptations.”