Scientists just cracked a mystery that's puzzled researchers for centuries; why are 90% of humans right-handed?

Why are 90% of humans right-handed? A new study published in PLOS Biology suggests that human right-handedness may have evolved because of two major evolutionary changes: upright walking and larger brains. Researchers from the University of Oxford analyzed data from over 2,000 primates across 41 species and tested multiple theories related to handedness.