Men's noses are an average of 10 percent bigger than women's noses due to differences in their physical builds and energy demands, researchers report.
The investigators tracked the nose size and growth of 38 people of European descent from the age of 3 until they were in their mid-20s. In general, boys and girls had the same nose size from birth until puberty began. After that, males had bigger noses than females.
Males tend to have more lean muscle mass, which requires more oxygen for muscle tissue growth and maintenance. Having a large nose means that more oxygen can be inhaled and transported in the blood to nourish the muscle, according to the University of Iowa researchers.
"This relationship has been discussed in the literature, but this is the first study to examine how the size of the nose relates to body size in males and females in a longitudinal study [where a group of people is followed over a long period of time]," study author Nathan Holton, an assistant professor in the College of Dentistry, said in a university news release.
The findings, published recently in the American Journal of Physical Anthropology, likely apply to most racial/ethnic groups, the researchers added.
The study also helps explain why modern humans have smaller noses than their ancestors did. Ancient humans had more muscle mass and required large noses to bring oxygen to that extra muscle tissue, Holton explained. He also noted that the rib cages and lungs of modern humans are smaller, which reinforces the idea that modern humans don't require as much oxygen as ancient humans did.
The American Academy of Otolaryngology -- Head and Neck Surgery has more about your nose.