We’re nice to our families. From an evolutionary perspective, that makes sense. But what makes us deal fairly with strangers? One theory holds that the development of large societies necessitated the creation of fairness, through institutions such as markets and religion that extend fairness to a so-called ‘anonymous other.’
In a study published in the journal Science , anthropologists and economists around the world spent 15 years studying communities of 2,000 to 10,000 individuals with highly variable social systems.