One of the biggest mysteries in human evolution has long puzzled scientists: Why are humans so overwhelmingly right-handed? Around 90% of people across cultures prefer using their right hand, a level of dominance not seen in any other primate species. Researchers have spent decades studying the brain, genetics, and development behind handedness, but the reason humans became so strongly right-handed has remained unclear.
Now, a new study led by researchers at the University of Oxford points to two major evolutionary milestones: walking upright and the dramatic growth of the human brain.
The research, published in PLOS Biology, was conducted by Dr. Thomas A. Püschel and Rachel M. Hurwitz from Oxford's School of Anthropology and Museum Ethnography, together with Professor Chris Venditti from the University of Reading. The team analyzed data from 2,025 monkeys and apes representing 41 different primate species.
Using Bayesian modeling that considered how species are evolutionarily related, the researchers tested several major theories about the origins of handedness. They examined factors including tool use, diet, habitat, body size, social structure, brain size, and movement patterns.
Upright Walking and Brain Expansion
