Care of the Infirm and Elderly
In most human societies, care of the infirm and elderly is part of the social system. While some cultures may allow the infirm and elderly to die for the greater good of the group, most cultures see caring for those weaker members as not only necessary, but meritorious. In contrast, great apes do not provide much care to the elderly or infirm. Generally, when apes are too weak to keep up and stay with the group, they end up being left behind to fend for themselves, usually resulting in their death. Apes depend on constant movement for foraging of dispersed food resources. Chimpanzee group members have been observed returning to visit with injured/sick group members (documenting the existence of concern for others), but transfer of food to the infirm has not been observed or documented.