ABSTRACT
The order of primates appeared 80 million years ago and includes more than 400 species divided into prosimians, real apes and anthropomorphic apes. Almost all primates have five digits on hand and foot with opposable thumbs, a non-specialized set of teeth (omnivorous diet) and binocular vision capable of perceiving colors. About 5 to 7 million years ago the Hominina sub-tribe from which the Australopithecine branch and the genus Homo evolved from the group of apes. Both are characterized by complete bipedal gait that freed the hands for manipulation of instruments. Numerous species have evolved within the genus Homo (Homo habilis, Homo ergaster, Homo erectus, Homo heildebergensis, Homo Neanderthalensis, Homo sapiens), which, over time, have shown a progressive increase in the volume of the cerebral cortex associated with greater skills in the social and technological fields. Studies in evolutionary psychology have shown that the evolutionary drive that led to the increase in brain volume in the different species of the genus Homo was mainly of a social nature. The increase in the cerebral cortex and in particular the frontal lobe has been related to the increase in the size of the fundamental social group. This group in chimpanzees is about 40 to 60 individuals; in Homo erectus of 80 individuals, in Homo heildebergensis of 100 individuals, in Homo Neanderthalensis of 110 individuals and in Homo sapiens of 150 individuals. The great ability to cooperate, which is characteristic of human beings, is supported by cognitive functions such as joint attention, shared intentionality and mind-reading. These are mental functions that are present only in rudimentary form in chimpanzees. These abilities, together with mental imagination, have been considered essential cognitive prerequisites for the development of language.
