Why did humans surpass all other primates? Are our brains so different? Part 1.

Abstract

This review is based on a conference presented in June 2023. Its main objective is to explain the cognitive differences between humans and non-human primates (NHPs) focusing on characteristics of their brains. It is based on the opinion of a clinical neurologist and does not intend to go beyond an overview of this complex topic. As language is the main characteristic differentiating humans from NHPs, this review is targeted at their brain networks related to language. NHPs have rudimentary forms of language, including primitive lexical/semantic signs. Humans have a much broader lexical/semantic repertory, but syntax is the most important characteristic, which is probably unique to Homo sapiens. Angular gyrus, Broca's area, temporopolar areas, and arcuate fascicle, are much more developed in humans. These differences may explain why NHPs did not develop a similar language to ours. Language had a profound influence on all other higher nervous activities.