Humans (Homo sapiens) are the most abundant and widespread species of primates, characterized by bipedality and large, complex brains enabling the development of advanced tools, culture and language.

Innate behavior is behavior that occurs naturally in all members of a species. Instinct is the ability of an animal to perform a particular behavior in response to a given stimulus the first time the animal is exposed to the stimulus. In other words, an instinctive behavior does not have to be learned or practiced.