The idea that Darwin himself presents in the Descent of Man,
that the growth of the human brain in evolution to its present size was stimulated by spiritual achievements of prehistoric and early humans, and that there is something like a co-evolution of the brain and culture, cannot be right, because these concepts are tied to a deterministic view of evolution.
However, one issue cannot be denied: Today’s theories of human evolution all follow the wrong Darwinian concept. Not only Merlin Donald but also Michael Tomasello and everyone else assign a decisive role to the mind, language, and culture of man in the development of the human brain.
In addition to language, the concepts of work, the production of stone tools and cooperation in the prehistoric and early human social groups are regarded as decisive factors on the way to becoming human beings.
On the other hand, it is quite clear: The development of the human brain cannot be explained as co-evolution of brain and mind because the human mind that could have done this did not yet exist.
Even language and culture, typical human forms of cooperation, cannot have arisen through co-evolution with the brain. The human spirit is an evolutionary innovation that cannot have arisen through co-evolution.