A model balancing cooperation and competition explains our right-handed world and the dominance of left-handed athletes

TL;DR

This paper presents a mathematical model explaining the predominance of right-handedness in humans as an evolutionary balance between cooperation and competition, supported by data from elite athletes and animal behavior.

Contribution

It introduces a minimal evolutionary model that accounts for population-level handedness and its variation across social and competitive contexts.

Findings

Population-level right-handedness explained by the model

Model predicts strong lateralization in social species with limited combat

Explains rarity of pawedness in animals

Abstract

An overwhelming majority of humans are right-handed. Numerous explanations for individual handedness have been proposed, but this population-level handedness remains puzzling. Here we use a minimal mathematical model to explain this population-level hand preference as an evolved balance between cooperative and competitive pressures in human evolutionary history. We use selection of elite athletes as a test-bed for our evolutionary model and account for the surprising distribution of handedness in many professional sports. Our model predicts strong lateralization in social species with limited combative interaction, and elucidates the rarity of compelling evidence for "pawedness" in the animal world.