Recent theories around Prefrontal Synthesis are useful to consider with regard to the evolution of the "modern mind". ".. the existence of a strong critical period for PFS acquisition creates an evolutionary barrier for behavioral modernity"[1]. In short, the PFS acquisition theory explains functionality of recursive language and imagination. These adaptations are thought to occur about 70k years ago.

[1] https://www.biorxiv.org/content/10.1101/166520v8.full, 2019