The Interdependence Hypothesis: How Human Evolution Evolved

Previous hypotheses:

(1) Big Mistake Hypothesis  --   collaboration evolved when humans lived in small groups. It is possible that collaboration had an advantage because it benefited kin and increased chances of reciprocity in the community. Reciprocity is critical because it determines an individual's reputation.

(2) Cultural Group Selection Hypothesis -- collaboration evolved in larger social groups. The hypothesis states that culture breads and individual's sense of altruism. The more altruistic a population is, the more successful it will be. Since humans tend to mimic one another, altruism becomes valorized by the community.

The Interdependence hypothesis is a new hypothesis of human evolution stating that at some point humans began to collaborate to survive and procreate. Collaboration first began in small populations and then spread to be a large societal norm.

When thinking about collaboration and altruism, people tend to use the prisoners dilemma as an example. However, there is also the "Stag Hunt Game," which states that individuals must collaborate with others to benefit; the benefits of collaboration are greater than those of any solo alternatives; and all solo alternatives must be forsaken in order to collaborate. Basically, if an individual can hunt a rabbit, but the group can hunt a deer (at the cost of losing the rabbit), then the group will collectively hunt the deer and have more food for the group. This is exhibited in human populations. It is not, however, exhibited in chimpanzees.

Since small communities benefited from working together, the community exhibited behaviors of altruism and collaboration. Once human populations began to grow and encounter other populations, collaboration allowed human sub-populations to better survive against increasing competition. Thus, collaboration was exhibited not only in individuals and small populations, but also in large communities and societies.

It is important to note that this explanation is a hypothesis, not a theory.

Source: http://americainclass.org/wp-content/uploads/2012/06/Tomasello-Michael-2012-Two-Key-Steps-in-the-Evolution-of-Human-Cooperation.pdf

http://www.eurekalert.org/pub_releases/2012-11/uocp-wit111612.php