Humans have almost always been predominantly right-handed — at least for the past 500,000 years, it is believed. Researchers found that fossilized human teeth show marks that suggest that more than 90 percent of prehistoric humans were right-handed, which is about the same percentage of right-handed people today.
More facts about handedness:
- Though there is evidence that handedness is genetic in humans, scientists are still simply not sure of exactly how it works.
- Humans aren't the only ones who are mostly right-handed: cockroaches and horses are generally right-handed as well.
- Studies show that right-handed people have, on average, a lifespan that is nine years longer than that of left-handed people, partially because left-handed people appear to be slightly more prone to accidents.