These monkeys don't make eye contact with each other, and they avoid physical contact except with family members. This living situation creates an "every monkey for himself" attitude, where macaques steal one another's food and act aggressively towards their neighbors.

Apes and monkeys in the wild live in close-knit families, generally isolated from other groups. They can be extremely territorial and aggressive if threatened. Recently, biologists studying chimpanzees in western Africa noticed a huge decline in the chimps' numbers as logging operations neared their home range. It seems that the loggers' machines chase chimps across territorial borders, resulting in a deadly conflict between opposing chimp groups.

In the case seen on NATURE, a chimp named Nsaba, a would-be leader of the troop, is vanquished by the older male Kalunde and his supporters. Defeated, Nsaba shows his submission by grooming Kalunde. Grooming, a behavior common to every primate species, serves to reinforce the connection between family and troop members. Later, Nsaba builds up support for his cause among the troop by grooming other chimps. After he gains his followers' trust, Nsaba is able to rally them together and oust Kalunde. His coup successful, Nsaba now reigns.