Evolution of mental traits linked to cultural development in modern humans and Neanderthals

Abstract

A cumulative process of cultural evolution occurred globally alongside the spread of anatomically modern humans (AMHs). This process of evolution was likely accompanied by global changes in mental and behavioral phenotypes, resulting in cultural differences between AMHs and Neanderthals. Globally, selective increases of frequencies were detected in alleles, which contributed to the suppression of neuroticism and advanced learning. This finding indicates that neuroticism was suppressed and learning behaviors developed through the global spread of AMHs. It suggests that global adaptation to psychosocial stress occurred, which contributed to cumulative cultural evolution by increasing cooperative learning. A comparison of phenotypic trends at the population level indicates that such globally occurring adaptive evolution, entailing neuroticism suppression and increased learning behaviors has been more significant in AMHs than in Neanderthals. However, adaptive evolution toward greater intelligence was more significant in Neanderthals than in AMHs. These findings suggest that mental traits involved in cultural development evolved differently in AMHs and Neanderthals, and that learning behaviors such as cooperative learning, rather than intelligence, played an important role in AMH evolution.