Richerson and Boyd have been spokesmen for explaining how culture transformed human evolution. Their book: Not by Genes Alone is the source of the quotations below. The “evolutionary properties of symbolically marked subgroups (tribes, religions, universities, etc) give rise to many problems and conflicts in complex societies.” However, without the tribal social instincts, we cannot explain why our societies are so different from other primates. The institutions of our complex societies are built on ancient and tribal instincts that have imperfections coming from cultural evolutionary processes.
“Impressionable observers risk imitating poorly adapted cultural variants, while conservative observers may miss out on valuable new techniques and social arrangements…We have various forms of fast and frugal transmission biases that give us a good chance of sweeping up good ideas and rejecting bad ones.”
“Modern societies by vastly enlarging the scope of non-parental transmission, have also magnified the chance of choosing maladaptive memes. Culture is sometimes adaptive, sometimes maladaptive, and sometimes neutral… Natural selection directly on genes never favored large scale cooperation.”
“Reversal of the correlation between wealth and reproductive success in the last two centuries.”
“As humans, we are unusually active agents in our own evolution, because we each choose which cultural variants to adopt and which to neglect”
“Much of the objection to applying Darwinian tools to the human case seems to come from a “visceral” dislike of picturing us as just “another unique species.”
Boyd and Richerson continue to argue strongly for the cultural niche over the cognitive niche. Their arguments are made especially strong by their discussion of the Inuits north of the Arctic Circle. We are not that much smarter than other creatures, but we have a unique ability to learn from others, especially using grammatical language. They suggest that the large amounts of valuable cultural information would have favored the evolution of bigger brains and of specialized cognitive abilities such as: overimitation, a functional understanding of artifacts, selective social referencing, and the use of “taxonomic inheritance and category-based induction for living kinds. The presence of culturally derived techniques and products such as fire, cooking, weapons, and other tools created new selection pressures acting on our bones, muscles, teeth, and guts. Our genetic and cultural inheritance interact to produce how we act.
Boyd, R & Richerson, P.J.(2005) Not by Genes Alone -How Culture Transformed Human Evolution. Chicago: University of Chicago Press.
Boyd, R, Richerson, P.J. & Henrich, J (2011). The cultural niche: Why social learning is essential for human adaptation. PNAS June 28, 2011, vol 108, suppl 2, pp 10918-10925.