Overview
- A peer-reviewed PLOS Biology study led by Oxford anthropologist Thomas Püschel analyzed 2,025 individuals across 41 primate species to test rival explanations for hand preference.
- The model finds that two traits best account for why about 90% of people are right-handed: bipedal locomotion that freed the hands and later increases in brain size that strengthened lateralization.
- Researchers used arm-to-leg length as a standard anatomical marker of bipedalism and combined it with brain size to estimate likely handedness in extinct ancestors.
- Ancestral reconstructions suggest a slight right bias in early hominins, a stronger bias within Homo (including H. ergaster, H. erectus, and Neanderthals), and a modern extreme in H. sapiens.
- Homo floresiensis stands out with weaker hand preference, consistent with its small brain and mixed walking-and-climbing locomotion, while most other primates show no population-level hand bias.