“Cultural Evolution: How Darwinian Theory Can Explain Human Culture and Synthesize the Social Sciences” by Alex Mesoudi

Darwin posited that three factors were needed for successful biological evolution: variation, competition, and inheritance. Mesoudi makes the case that these same factors are necessary to effectively transmit traits culturally. However, “two societies living in the same environment can have entirely different behavioral practices,” especially the more limited their amount of inter-group contact. Cultural adaptation is favored over innate change in environments that are rapidly transforming because genes cannot adapt as quickly in the span of one biological generation. Cultural learning is also favored over individual learning because one does not need to bear all the costs of trial and error and one can benefit from piggybacking on new inventions and techniques not developed by oneself. Evolution, biological and cultural, however, is not a predetermined path that is ever progressing. “Humans are not at the top of the evolutionary ladder, because there is no ladder of which to be at the top. There is only local adaptation to local environments, which does not necessarily translate into global increases in fitness, and does not result in inevitable and entirely predictable evolutionary change along a prespecified course.”

Richard Dawkins coined the term “meme” to refer to a discreet unit of cultural inheritance or a cultural replicator, akin to a gene in biological evolution. “In culture, on the other hand, one can learn beliefs, ideas, skills, and so forth, not just from one’s biological parents (termed “vertical cultural transmission”) but also from other members of the parental generation (“oblique cultural transmission”) and from members of one’s own generation (“horizontal cultural transmission”)…. People might preferentially copy very prestigious models who have high social status or excel in a particular skill (prestige bias). Alternatively, they might preferentially copy models who are similar to them in dress, dialect, or appearance (similarity bias) or preferentially copy older models (age bias).”

Finally, when looking at a particular set of cultures “within-group diversity and between-group diversity should be inversely correlated.” One specific area where Mesoudi stresses cultural evolution is language. In fact, Darwin stated, “a struggle for life is constantly going on amongst the words and grammatical forms in each language. The better, the shorter, the easier forms are constantly gaining the upper hand.” There is also an interplay back and forth between biological and cultural adaptation and evolution. “The social brain hypothesis holds that the large brains of primates, including and especially humans, evolved to deal not primarily with ecological problems such as finding food or using tools, but rather to solve social problems…. Social interactions give rise to a range of particularly challenging problems, such as coordinating actions with others, successfully communicating intentions, forming coalitions and alliances, deception, trying not to be deceived by others, and so on, which demand quite sophisticated cognitive abilities.” The more social interactions and bigger the social group of a particular species of primate the bigger the brain, with humans having the biggest brains of all. We are the paramount social animal and we have achieved our primacy through a cultural inheritance that was the work of human cooperation without any explicit human design.