A strange scientific debate that has gone on for the better part of the century, right alongside why men have nipples, may have been solved: why are humans the only species with a chin?

Researchers at the University of Iowa delved into the question, comparing modern human jaws with the jaws of early humans and Neanderthals. One theory has our chins developing due to mechanical forces, such as chewing. But lead researcher and assistant professor in the Department of Orthodontics Nathan Holton explained in a paper published in the Journal of Anatomy that mechanical forces actually discouraged chin growth. Analyzing 40 people from toddlers to adults and using facial and biomechanical analyses, they found that chewing simply did not give enough