Neanderthals had big right arms. Scientists think they now know why.
Up until recently, it was the accepted hypothesis that Neanderthals had unusually large biceps and triceps on their right arms because of the use (thrusting) of spears; however, new research suggests that it was not the act of killing game that resulted in their disproportionately large right arm muscles but rather the scraping of the animal skin (to be used for shelter or clothing) after it was killed.
“Neanderthals have really interesting upper bodies,” says researcher Colin Shaw, a biological anthropologist at the University of Cambridge in England. “If you and I are both right-handed, you’d expect 4 to 13 percent asymmetry between our arms. Neanderthals have up to 50 percent or more asymmetry. They were doing something with their dominant arms that were either more intense or repetitive or both than we do today. The only population of modern people that we see who are similar are tennis players, who hit tennis balls many, many years aggressively.” (Live Science)
It’s funny how scientists will bend over backwards to outdo each other when it comes to explaining things that they have scant proof for, but refuse to acknowledge the most reasonable explanations.
In this case, Neanderthals did likely develop large arm muscles on their right arms due to scraping of skin, but it probably wasn’t that of an animal they killed. The scraping of skin happened due to overly zealous autoerotic activities, as their wives (cavemates?) were too busy browsing the local woods for the latest berries.