Overview
- The peer-reviewed PLOS Biology study released Monday by researchers at Oxford and Reading examines why about 90% of people worldwide prefer the right hand.
- The team tested competing ideas using data on 2,025 individuals from 41 primate species analyzed with Bayesian models that account for evolutionary relationships.
- Humans stopped looking like outliers once the models included brain size and the arm-to-leg length ratio, a standard marker of upright walking.
- Reconstructed timelines indicate a mild rightward bias in early bipedal hominins that grew stronger across the Homo lineage, including in Homo erectus and Neanderthals.
- One predicted exception is Homo floresiensis, which shows a weaker bias consistent with its small brain and mixed climbing and walking, and the authors call for follow-up work on why left-handedness persists and how culture might shape hand use.