What Is the Purpose of Armpit Hair?

Though some subscribe to creationist beliefs, it is fairly common scientific belief that Homo sapiens evolved from earlier homonids that had copious amounts of body hair, not just in their armpits and pubic regions but all over every inch of skin. Over many millennia, less and less hair seems to be the path that natural selection has taken, though some believe the hair that remains serves some purposes. Armpit hair, it is believed, not only nurtures a heated, musty nest of mate-attracting pheromones, but also offers protection from chafing. Women who regularly shave their armpits and other regions in 2011, however, do not seem to mind its absence.

Though it could easily be considered conjecture, some scientists believe that armpit hair has continued to be part of the human package mostly due to pheromones. The apocrine glands of the armpits are a major producer of these secretions, which many animals and humans emit to attract mates. More hair present results in a more protein-rich environment for chemical communication via pheromones. It is actually the bacteria of the armpit hair that breaks down sweat into something stinky, since pheromones are considered odorless.

Several perfume and cologne manufacturers claim to include human pheromones in their recipes to give an added appeal. Some scientists dispute whether it is possible to distill these odorless hormones, stating that many of these concoctions contain synthetic versions of the body's natural hormones. Regardless of the scent attraction debate, some speculate that oil-rich armpit hair is useful for lessening the amount of friction that is produced between between the upper arm and torso during movement. Others, however, insist that the bristly hairs actually add to the friction and do not provide any lubrication at all.

Researchers started suspecting and investigating the existence of hormonal pheromones more than 100 years ago. It was not until 1959 however, that it was named as such, by two scientists, the Swiss entomologist Martin Luscher and the German chemist Peter Karlson. The word "pheremone," means in Greek, "carrier of excitement." The discovery, however, was made with termites instead of humans and their armpit hair.

According to the National Academy of Sciences, pheromone research has largely focused on insect attraction, primarily in the pest management field rather than the pheromone content of human armpit hair. In 1980 for instance, 4,000,000,000 beetles were lured by pheromones to traps in Norway and Sweden to stem an infestation that threatened crops. The technology has spread worldwide, though an understanding of human pheromones is still largely elusive in 2011.