Body Odor Gives Away Age

It might not be just your looks or attitudes that give away your age. In fact, something more subtle is at play. It seems that humans can identify another human's age based on simply body odor.

The "old-person smell" is a constant theme found in many cultures. The Japanese even have a word for it - kareishū.

Interestingly enough, in the study, the smell of older people was rated as less intense and more neutral than the body odors of younger people.

Scientists theorize that body odors play an important role for animals in the selection of a mate, and the same thing could be happening to us.

"Similar to other animals, humans can extract signals from body odors that allow us to identify biological age, avoid sick individuals, pick a suitable partner, and distinguish kin from non-kin," said senior author Johan Lundström, a sensory neuroscientist at the Monell Center.

Older males, signaled by their body odor, might make more desirable mates due to their genes and social standings. On the other hand, older females are less attractive because their reproductive systems are not as fertile.

Although our sense of smell is not as advanced as many animals, odors play a strong, nuanced role in our perception. The sense most connected with our memories is smell. Thousands of dollars are spent on exotic perfumes and colognes to make us more attractive to others. And even though we do not navigate by our smell, or use it to identify one another, an overwhelming stench can cause even the stoutest of hearts to flee a room.

"Elderly people have a discernible underarm odor that younger people consider to be fairly neutral and not very unpleasant," said Lundström. "This was surprising given the popular conception of old age odor as disagreeable. However, it is possible that other sources of body odors, such as skin or breath, may have different qualities."