Men's noses are, on average, 10 percent bigger than women's (at least for populations of European descent). This can be pretty easily observed. The fascinating part is why.
Researchers now say schnoz size relates to a person's physique, and the energy required to maintain it. As explained on Phys.org
Males in general have more lean muscle mass, which requires more oxygen for muscle tissue growth and maintenance. Larger noses mean more oxygen can be breathed in and transported in the blood to supply the muscle.
Obviously this is a generalization---the body types and noses of men and women show plenty of variation between individuals. But the hypothesis consistently rang true in a recent study that tracked the nose size and growth of 38 Iowans, from the age of 3 to about 25. During childhood, the boys and girls had comparably sized sniffers, as evaluated by X-rays and physical examinations. Nasal growth kicks in around age 11, with the onset of puberty. At this point, the boys' metabolisms sped up, their energy consumption rose, and both their nasal cavities and their nose itself grew faster than the girls'. This idea of correlating nose size with muscle oxygenation could also explain why modern humans have smaller noses than, say, Neanderthals. Early hominids had more muscle mass and therefore needed bigger noses to bring in more oxygen, according to the study
published in the American Journal of Physical Anthropology. This is further supported by the fact that our predecessors' lungs and rib cages were also larger than today's average European. Keep that in mind before bemoaning a big nose in the mirror. Image credit: auremar/Shutterstock