Why do men have bigger schnozes than women do? A new study suggests the answer to that question has its roots in our evolutionary history.
The study showed that men's noses are 10 percent bigger than women's, and the researchers behind the study pin the difference on the fact that men's bodies need to bring in more oxygen to feed their greater muscle mass. Bigger noses, better oxygenation, the theory goes.
This study was published Oct. 31 in the American Journal of Physical Anthropology.
Male noses (shown at bottom) grow disproportionately larger than female noses (shown at top) beginning at puberty, a University of Iowa study has found. The reason: Males need to breathe in more oxygen to feed muscle mass than females.
The finding may also help explain why the noses of Neanderthals -- the closest extinct relatives of modern humans and even more heavily muscled than we are -- were much bigger than those of modern humans.
"The large noses in groups like Neanderthals may be constrained to be large because they had greater mass and therefore required more oxygen," study author Nathan Holton, an assistant professor at the University of Iowa College of Dentistry, told LiveScience. "With the reduction in body mass seen in modern humans, these constraints would be lifted and noses would reduce in size."
The researchers noted that differences in nasal size between boys and girls become apparent around age 11, according to a written statement released by the university. That's when males start to grow more lean muscle mass and females develop more fat mass.
"We have shown that as body size increases in males and females during growth, males exhibit a disproportionate increase in nasal size," Holton said in the statement.
The research was based on the noses of 18 men and 20 women, all of European descent. Holt said he believed the finding would also hold true for other ethnic groups but acknowledged that more research would need to be done to confirm that.
No matter what, bigger noses may not mean a better sense of smell. A 2002 study showed that women tend to have a keener sense of smell than men. The scientists behind that study linked women's better ability to smell to the hormone estrogen, which has a role in increasing odor sensitivity.
Evidently, size doesn’t always matter.