The sharing of meat from hunting was a kind of tribal insurance. Meat wouldn't keep for long anyway, and in sharing your catch with others, there was an expectation that they would return the favor. This system of sharing did not mean that the hunter was being especially altruistic.
原住民的分享也是一種「保險」的行為，過去因為獸肉無法久藏，與他人分享，等於將自己的份託給別人保管，別人自然會給予回饋，它的分配規矩，讓獵物主不至因為分享而吃虧。