Increasing population size can inhibit cumulative cultural evolution.

Area of Science:

• Cognitive Science
• Evolutionary Psychology
• Human Behavior

Background:

• Cumulative cultural evolution (CCE) is the process by which innovations are built upon over generations.
• The impact of population size on CCE, particularly in technological development, remains a subject of debate.
• Understanding how social learning and population dynamics influence cultural transmission is crucial.

Purpose of the Study:

• To experimentally investigate the relationship between population size and the cumulative cultural evolution of technology.
• To determine if larger social learning groups enhance the development and adaptation of artifact performance.
• To explore the mechanisms by which population size might affect CCE.

Main Methods:

• A large-scale experiment (n=543) using a transmission-chain design to study paper plane construction and flight distance.
• Manipulation of population size: participants learned from 1, 2, or 4 models from the previous generation (social learning).
• Comparison with an individual learning condition (asocial learning) and analysis of flight distance improvement over generations.

Main Results:

• Larger populations generated greater variation in paper plane performance but did not enhance CCE.
• An inverse relationship was observed: flight distance improved in the 1-model condition but not in 2- or 4-model conditions.
• Individual learning showed improvement comparable to the 1-model social learning condition, highlighting trial-and-error importance.

Conclusions:

• Larger populations do not automatically enhance artifact performance through cumulative cultural evolution.
• Potential cognitive overload from excessive variation in larger groups may impede selective copying of optimal solutions.
• CCE enhancement by larger populations may be contingent on specific conditions, not a universal outcome.