Foundations of Human Sociality (Introduction and Overview) The self-regarding and outcome oriented picture of human behavior presented in traditional economics does not explain why humans care so much about each other and about how social interaction is carried out, not just the end goals. The Ultimatum Game, designed by Werner Guth, is just one illustration of how real people will not always follow the dictates of self-interested rationality. Two subjects are given a sum of money, one is given the power to divide the sum, and the other can either accept or reject (in which case neither get any money).
Robin Dunbar Professor Robin Ian MacDonald Dunbar (born 28 June 1947) is a British anthropologist and evolutionary psychologist and a specialist in primate behaviour. He is currently head of the Social and Evolutionary Neuroscience Research Group in the Department of Experimental Psychology at the University of Oxford and is best known for formulating Dunbar's number, a measurement of the "cognitive limit to the number of individuals with whom any one person can maintain stable relationships". Education
Dunbar's number is a suggested cognitive limit to the number of people with whom one can maintain stable social relationships. These are relationships in which an individual knows who each person is and how each person relates to every other person. This number was first proposed by British anthropologist Robin Dunbar, who found a correlation between primate brain size and average social group size. By using the average human brain size and extrapolating from the results of primates, he proposed that humans can only comfortably maintain 150 stable relationships. Proponents assert that numbers larger than this generally require more restrictive rules, laws, and enforced norms to maintain a stable, cohesive group.
Symbiogenesis Symbiogenesis is the merging of two separate organisms to form a single new organism. The idea originated with Konstantin Mereschkowsky in his 1926 book Symbiogenesis and the Origin of Species, which proposed that chloroplasts originate from cyanobacteria captured by a protozoan. Ivan Wallin also supported this concept in his book "Symbionticism and the Origins of Species". He suggested that bacteria might be the cause of the origin of species, and that species creation may occur through endosymbiosis. Today both chloroplasts and mitochondria are believed, by those who ascribe to the endosymbiotic theory, to have such an origin. A fundamental principle of modern evolutionary theory is that mutations arise one at a time and either spread through the population or not, depending on whether they offer an individual fitness advantage.