# NuseReal
Miscellaneous news
Scientists may have finally cracked why 90% of humans are right-handed — and the answer has nothing to do with our hands, it has to do with our legs (LINK) — 22 May 2026
— Space Daily: An Oxford team's approach was to test all the major hypotheses simultaneously against data from 41 different species, looking for which combination of factors actually explained the cross-species pattern in which humans are the extreme outlier. No single factor explained the pattern. No other primate species shows population-level handedness anywhere close to this scale. Chimpanzees, our closest relatives, show only mild handedness preferences, and the preferences are roughly evenly split between left and right across the population.
— The Oxford team found that two factors together accounted for the human anomaly. The first factor was brain size, specifically the dramatic expansion of brain size that occurred in the human lineage over the last several million years. The second factor was the ratio between arm length and leg length, which is a standard anatomical marker of bipedal locomotion. The 90 percent right-handedness figure was what their model predicted for an animal with our specific combination of brain size and bipedal commitment. The other primates, with smaller brains and more arboreal locomotion, were predicted by the model to have weaker handedness preferences, which is what the data show. The proposal is that bipedalism freed the hands from the task of locomotion. The specialization could include, among other things, the development of strong handedness, in which one hand becomes the dedicated tool-using and fine-manipulation hand while the other becomes the assisting hand.
