This article discusses the emergence of modern human behavior during the Late Pleistocene, focusing on the transition from the Middle Stone Age (MSA) to the Late Stone Age (LSA) in Africa and its spread to other regions. The study highlights the role of demography in the maintenance and spread of cultural complexity. It shows that regional population densities and migratory activity influence the spatial structuring of cultural skill accumulation. Genetic estimates indicate that early Upper Paleolithic Europe had similar population densities to sub-Saharan Africa when modern behavior first appeared. The article also explores the timing of the appearance of modern behavior in different regions, noting that it varied geographically and temporally. The study uses a transmission model to demonstrate how demographic factors can affect the accumulation of culturally inherited skills. The results suggest that increased population size or migratory activity can enhance the accumulation of cultural skills, similar to increasing the size of a single population. The study also addresses the delay between the emergence of anatomically modern humans (AMH) and the appearance of modern behavioral traits, proposing that demographic factors played a key role in this delay. The article cites numerous references and provides links to supporting materials, including online resources and additional articles related to the topic.This article discusses the emergence of modern human behavior during the Late Pleistocene, focusing on the transition from the Middle Stone Age (MSA) to the Late Stone Age (LSA) in Africa and its spread to other regions. The study highlights the role of demography in the maintenance and spread of cultural complexity. It shows that regional population densities and migratory activity influence the spatial structuring of cultural skill accumulation. Genetic estimates indicate that early Upper Paleolithic Europe had similar population densities to sub-Saharan Africa when modern behavior first appeared. The article also explores the timing of the appearance of modern behavior in different regions, noting that it varied geographically and temporally. The study uses a transmission model to demonstrate how demographic factors can affect the accumulation of culturally inherited skills. The results suggest that increased population size or migratory activity can enhance the accumulation of cultural skills, similar to increasing the size of a single population. The study also addresses the delay between the emergence of anatomically modern humans (AMH) and the appearance of modern behavioral traits, proposing that demographic factors played a key role in this delay. The article cites numerous references and provides links to supporting materials, including online resources and additional articles related to the topic.