At the worst extreme, many traditional societies get rid of their elderly in one of four increasingly direct ways: by neglecting their elderly and not feeding or cleaning them until they die, or by abandoning them when the group moves, or by encouraging older people to commit suicide, or by killing older people. In which tribal societies do children abandon or kill their parents? It happens mainly under two conditions. One is in nomadic, hunter-gatherer societies that often shift camp and that are physically incapable of transporting old people who can't walk when the able-bodied younger people already have to carry their young children and all their physical possessions. The other condition is in societies living in marginal or fluctuating environments, such as the Arctic or deserts, where there are periodic food shortages, and occasionally there just isn't enough food to keep everyone alive. Whatever food is available has to be reserved for able-bodied adults and for children. To us Americans, it sounds horrible to think of abandoning or killing your own sick wife or husband or elderly mother or father, but what could those traditional societies do differently? They face a cruel situation of no choice. Their old people had to do it to their own parents, and the old people know what now is going to happen to them.