We know from embryonic development, and Darwin has stressed in great detail that

Parade, Cusco, Peru, 27. 8. 1989
conclusions about phylogenesis can be drawn from the ontogenesis of individuals of today. Why shouldn’t this line of reasoning be applied to brain and mind?
Every infant already has a human brain before it can absorb cultural stimulation from its environment. This should also apply for phylogeny, the tribal history of humans. The chronological sequence of brain and mind development is basic but raises new questions about the development of the brain.
From the moment the human brain exists in its present form, there is the possibility of the emergence of the human mind and human culture – but only the possibility.
What mechanism actually led to the development of culture and spirit, how the change of function of the brain – which, in addition to its previous functions, became the biological seat of the mind – took place, are exciting questions. Through its change of function, the brain became an evolutionary innovation in terms of the theory of evolution.