Learning
"The brain did not evolve for culture, but culture evolved to be learnable by the brain."

"A classical, although often implicit, view in social science is that the human brain, unlike that of other animals, is a learning machine which can adapt to essentially any novel cultural task, however complex. We humans would be liberated from our past instincts and free to invent entirely new cultural forms. 

"What I am proposing is that the human brain is a much more constrained organ than we think, and that it places strong limits on the range of possible cultural forms. Essentially, the brain did not evolve for culture, but culture evolved to be learnable by the brain. Through its cultural inventions, humanity constantly searched for specific niches in the brain, wherever there is a space of plasticity that can be exploited to 'recycle' a brain area and put it to a novel use. Reading, mathematics, tool use, music, religious systems -- all might be viewed as instances of cortical recycling." - Stanislas Dehaene

Interview: Your Brain on Books