Why 90% of humans are right-handed may trace back to walking on two legs

An Oxford study suggests human right-handedness did not arise from one genetic switch, but evolved gradually alongside bipedal walking.

Researchers found humans look unusual in handedness models only after accounting for upright locomotion and larger brain size.

The pattern implies right-handedness may have emerged first with bipedalism and later been reinforced by encephalization.

The finding offers a broader evolutionary explanation for why about 90% of people are right-handed.