Overview

This is part 1 of "14 lessons from A Cooperative Species, Human Reciprocity and Its Evolution" This part gives the highlights of evolutionary biology and places cooperative economics in context with competing theories.

Part i presents the key takeaways.

Part 0 explores each of the 14 lessons.

Evolution of sociobiology

“I shall argue that a predominant quality to be expected in a successful gene is ruthless selfishness. This gene for selfishness will usually give rise to selfishness in individual behavior.” -- Richard Dawkins, The Selfish Gene (1976)

“Selfish and contentious people will not cohere, and without coherence, nothing can be effected. … social and moral qualities would tend … be diffused throughout the world. Charles Darwin, The Descent of Man (1873)

With which do you think they agree? Yes, Darwin.

Numerous advances in sociobiology also inform social behavior:

• In 1971 Edward O. Wilson showed the central importance of social structure in The Insect Societies. He followed this in 1975 with Sociobiology: The New Synthesis.
• In 1970, George Price provided an ingenious method for the analysis of selection processes operating at multiple levels, providing a way to study the evolution of social behavior in group-structured populations.
  • This shows how behaviors can emerge at a group level that are not evident at the lower level.
  • Even though genes are selfish, groups can behave altruistically.
  • This is known as “multi-level selection”
• In 1973, Cavalli-Sforza and Feldman published “Cultural versus Biological Inheritance”, arguing for gene-culture coevolution
• in 1973, John Maynard Smith and George Price published “The Logic of Animal Conflict”. This paper launched the field of evolutionary game theory.

Multi-level selection may be of considerably greater importance among humans than among other animals given the following characteristics:

• Advanced cognitive and linguistic abilities.
• Capacity to maintain group boundaries.
• Ability to formulate general rules of behavior for large groups.
• Substantial influence of cultural inheritance.

Among the consequences of these are minimizing within-group differences through egalitarianism, consensus decision making and conformist behaviors.

Other animals do some of these things, but no animal does all of these as well as people do. These caused groups to win out over other groups, favoring the individual characteristics within groups that won.

Competing alternative explanations

A rather different interpretation of human altruism and its evolution is that, behaviors that seem to be altruistic are just self-interest with a long time horizon.

• This approach takes reciprocal altruism as its starting point and shows how, when interactions are frequently repeated, individuals may enhance their fitness by a mutualistic form of helping based on the expectation of reciprocation in the future.
• Variants of this approach developed in models of indirect reciprocity and costly signaling show that helping others may be repaid not only by the targets of one’s help but also by others wishing preferentially to be associated with the helpful.

Competing models for explaining cooperation

1. Inclusive Fitness -- 1930, 1964

   • Kin-based Altruism -- 1964
   • Group-based Altruism (multi-level selection) -- 1977 , 1982, 1990
   • Network-based Altruism -- 2006

2. Reciprocal Altruism & Mutualism -- 1971

   • Signaling Reputation -- 1973 , 1990 , 1975
   • Indirect Reciprocity -- 1987 , 1986
   • Repeated Games Folk Theorem -- 1981 , 1986

An important parameter in these models is what economists term the rate of time preference. For example, reciprocal altruism could have gotten started by piggybacking on kin-based altruism.

Perhaps humans are simply able to mentally simulate the future better. Perhaps we simply have a longer time preference parameter. After all, non-human animals are relatively more impatient. Behaviors that at first appeared to be reciprocal have on further study been better explained as simple mutualism in which the benefit to the actor compensates for the cost of the action regardless of the action taken by the other.

Reciprocal Altruism in Large Groups

To illustrate the consequences of extending the reciprocal altruism model to groups larger than two, we will develop an agent-based model. A large population consists of N groups of n members each, and each group plays a public goods game repeatedly d times. We will call this series of d rounds an encounter.

Reputation: Indirect Reciprocity

Here they steel man a competing theory, called the standing model. This is an alternative mechanism of cooperation where individuals remember who cooperated with their partners in the previous round and those who did not.

• An individual who cooperated in the previous round is considered to be “in good standing”.
• The only way an individual can fall into bad standing is by defecting on a partner who is in good standing.
• An individual can always defect when his partner is in bad standing without losing his good standing status.

The “standing strategy” is :

1. cooperate if and only if your current partner is in good standing,
2. except that if you accidentally defected the previous period, then
3. cooperate in this period unconditionally, thereby restoring your status as a member in good standing.

Indirect reciprocity and signaling models are similar in that the payback for the individual’s cooperative action comes from third parties.

The two models differ in a subtle way.

• In the signaling model the third party responds favorably because the signal is correlated with some desirable but unobservable property of the actor.
• In the indirect reciprocity model the signal (cooperating with those in good standing) is the desirable property itself.

Example of indirect reciprocity: I want to associate with the hunter who shares his ample prey with other members of the group because I too would like a share of meat.

Example of the signaling model: I want to associate with the hunter because the fact that he has lots of meat to share indicates that he is physically able and would be a good mate or coalition partner. In other words, having meat to share is correlated with some other desirable quality.

Part i : Introduction.

Part 0 : Overview of 14 key lessons of cooperative economics.

Part 2 : Failures of non-cooperative theory.

Part 3 : Evolutionary economics, rise of institutions, and the co-evolution of genes and culture.