ABSTRACT
Modern human behavior can be linked to behavior observed in other primates. Thus human behavior can be better understood through the use of the comparative method. Some similarities may be analogous and others homologous. The descriptions of primate behavior are arranged under four headings: ecology, sociality, life cycle, and cognition. Touching in human life may be derived from primate grooming. Grooming diminished in humans with the rise of language for social communication. Primates give birth during the inactive part of the daily cycle, which means at night for anthropoids. Humans follow the same pattern, due to the same mechanisms. Only children above the age of four years could display some ability to reason by non-causal similarity. Chimpanzees and bonobos shared this ability, but gorillas and orangutans did not. The stimulus elicited activity in several homologous regions of the human and monkey brains, which suggests a neural basis for tool use that goes back beyond the chimpanzee-human lowest common ancestor (LCA).
