Cultural Evolution of Human Cooperation: Summaries and Findings

Title:  Cultural Evolution of Human Cooperation: Summaries and Findings
Pub:  Genetic and Cultural Evolution of Cooperation,  ed. Peter Hammerstein, MIT  Press, in cooperation with Dahlem University Press
Publication Date:  2003
URL:  http://www.des.ucdavis.edu/faculty/richerson/Dahlem%209%2029%2002.prn.pdf

Authors:

Boyd, Robert,Henrich, Joseph, Richerson, Peter

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 caste.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.

One Sentence:

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.

One Paragraph:

Culture  -- “the capability of human groups to transmit and decode knowledge  across time and space, through the individual capacities of learning and  imitation and via communication media such as speech and writing“  -- has driven the evolution of cooperation over the past 250,000 years. "We  believe that the human capacity to live in larger-scale forms of tribal  social organization evolved through a coevolutionary ratchet generated  by the interaction of genes and culture. Rudimentary cooperative  institutions favored genotypes that were better able to live in more  cooperative groups." The willingness and toolset for cooperation with  strangers helped our species evolve from lower primates and shaped human  nature with a predisposition to cooperate with tribemates, but  human-created (i.e., cultural) institutions used innate capacities as  levers to overcome other limitations to human social cooperation. The  capacity for "moral emotions" such as shame, for example, enable  cultural workarounds such as the institutionalization of norms through  altruistic punishment, that harmonize self-interest with group benefits.

One Page:

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.