Cultural Evolution of Human Cooperation: Summaries and Findings

Summary of: Cultural Evolution of Human Cooperation: Summaries and Findings

Innate human propensities for cooperation with strangers, shaped during the Pleistocene in response to rapidly changing environments, could have provided highly adaptive social instincts that more recently coevolved with cultural institutions; although the biological capacity for primate sociality evolved genetically, the authors propose that channeling of tribal instincts via symbol systems has involved a cultural transmission and selection that continues the evolution of cooperative human capacities at a cultural rather than genetic level — and pace.

Publication Reference

Published in/by
Genetic and Cultural Evolution of Cooperation, ed. Peter Hammerstein, MIT Press, in cooperation with Dahlem University Press
Date
2003

Findings

  • Genetically-evolved human capacities to invent and communicate led to social institutions that favored genotypes better able to live in cooperative groups — human nature is, to a large degree, defined by our social capabilities -- but the invention of culture took the evolution of cooperation into the symbolic and out of the genetic level. Authors call this the "social instincts hypothesis."
  • Culture is an inheritance system that uses symbols, imitation, norms, and learning to transmit behaviors, which are channeled by institutional workarounds that "take advantage of a psychology evolved to cooperate with distantly related and unrelated individuals belonging to the same symbolically marked 'tribe.'"
  • "Humans are prone to cooperate, even with strangers; cooperation is contingent on many things, institutions matter, institutions are the product of cultural evolution, variation in institutions is huge."
  • "We propose that group selection on cultural variation is at the heart of human cooperation, but we certainly recognize that our sociality is a complex system that includes many linked components. Surely, without punishment, language, technology, individual intelligence and inventiveness, ready establishment of reciprocal arrangements, prestige systems, and solutions to games of coordination, our societies would take on a distinctly different cast….Thus, a major constraint on explanations of human sociality is its systemic structure."
  • "People are innately prepared to act as members of tribes, but culture tells us how to recognize who belongs to our tribes, what schedules of aid, praise, and punishment are due to tribal fellows, and how the tribe is to deal with other tribes: allies, enemies, and clients."
  • Cultural evolution uses the same mechanisms as biological evolution, mobilizing capacities such as tribal cooperation for new purposes – ideologies such as religions and empire became possible through symbolic media such as ritual and scripture, and organized larger and more complex institutions.
  • Nationalism on the scale of modern states taps tribal social instincts of populations by means of literate communities and the institutions they enable. These are Benedict Anderson's "imagined communities." Anderson pointed to the newspaper in particular as the vehicle of mass media that enabled literate people to organize around shared cultural, economic, political interests.

Although Darwin's 19th century advocates stressed the role of competition in natural selection, Darwin established speculation about cultural evolution in regard to human cooperation: "It must not be forgotten that although a high standard of morality gives but slight or no advantage to each individual man and his children over other men of the tribe, yet that an increase in the number of well-endowed men and an advancement in the standard of morality will certainly give an immense advantage to one tribe over another. A tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to aid one another, and to sacrifice for the common good, would be victorious over most other tribes; and t his would be natural selection."

The authors note that human social complexity is far beyond that of other social animals, and that biological mechanisms of kin selection and reciprocity are not adequate to fully explain human social behavior. Culture, defined as "information stored in individual brains (or in books and analogous media) that was acquired by imitation of, or teaching by others," has the properties of transmission forward through time and selection of successful strategies in common with genetic evolution. As Homo sapiens evolved, the mental and social capacity for cooperative work was highly adaptive for groups of small, relatively weak creatures with neither fangs nor claws nor wings. "Social instincts" enabled humans to band together in groups larger than the 50 individuals that our brain size allows in other primates. But that made cultural transmission of learning possible, which over-rode genetic group selection.

Although the Pleistocene era, with its radical climate changes, could have exerted long-term pressure on genetic group selection, the rapid evolution of social complexity over the past 10,000 years has not been long enough for significant genetic selection. Culture is both enabled by genetically-shaped human sociality, and is a means of progressively ratcheting mutually beneficial social cooperation. Once sociality, learning, and symbolic media make it possible to externalize and transmit individual learning, cooperative invention changes the game. Individual innovators can gain advantage through prestige and reputation, but only by displaying what they know, while learning and innovation enable the entire tribe to benefit from their innovations.

Culture harnesses and channels social instincts, enabling the creation of institutions. Norms enable the diffusion of enforcement of altruistic punishment through the population, leveraging emotions such as anger and shame to guard against free-riding, defection, and exploitation.