Scientists link right-handedness in humans to bipedalism and brain size

Among the many quiet signatures of what makes us human, the simple preference for one hand over the other has long puzzled scientists. Now, Oxford researchers tracing handedness across 41 primate species and 2,025 individuals have found that two ancient turning points — the rise of bipedalism and the expansion of the brain — together explain why roughly nine in ten humans are right-handed. The finding suggests that our dominant hand is not a trivial anatomical quirk but a visible trace of the neural reorganization that gave rise to language, tool-making, and the cognitive depth that distinguis