Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. What do Lady Gaga, Barack Obama, Bill Gates, Paul McCartney and Justin Bieber have in common with Ronald Reagan, Jimi Hendrix, Judy Garland, Fidel Castro and David Bowie? They are all left-handed, a trait shared by roughly 10% of people. But why are some people left-handed while most are righties?

Our brains could have more in common with our ape cousins than previously thought, which might require us to rethink ideas on the evolution of brain specialism in our early human ancestors. The left and right sides of our brains aren't symmetrical; some areas on one side are larger or smaller, while other parts protrude more. The pattern of these anatomical differences, or asymmetries, was thought to be uniquely human, originating when our brain hemispheres became specialised for certain tasks, such as processing language with the left side. Now, it seems the pattern came first – before humans evolved. Brain pattern comparisons between humans, chimpanzees, gorillas and orangutans reveal that our brains' left-right differences aren't unique, but shared with great apes.