Our species’ ecological success is supported by our ability to selectively learn beneficial social information, resulting in the accumulation of innovations over time. Population size affects the social information available to subsequent generations of learners and constrains cumulative culture.
Population structure constrains the flow of social information and can promote the accumulation of innovations by bringing culturally distinct groups into contact. Effective population structure results from a combination of structural barriers (e.g., lack of contact between individuals) and behavioral barriers (e.g., unwillingness to share social information).
Compared with non-human primates, humans live in large networks of unrelated individuals that might be conducive to the accumulation of cultural innovations. This social structure might partly result from selection pressures linked to our extensive reliance on culturally accumulated knowledge.