Ever since human beings first delved into caves for shelter, from both animals and the weather, sharing has been a part of life as we know it. As far back as these cavemen, sharing was used to both promote friendship, and also occasionally to promote survival of the group. Keep in mind however, that this was back when food was scarce, and involved a large expenditure of energy to acquire, such that should one tribe member have a large amount of food, he could be expected, as a member of the tribe, to share this food with the other members, and in this way prevent the tribe from dying of starvation. Sharing was also used as a way to secure a mate, by sharing his or her food with another, singular tribe member, that same tribe member would feel indebted towards the provider, while also seeing him as powerful, because not only does he hold the food, he also has the will to share it. Nowadays though, although in first world countries food is no longer an issue, and does not play such la...