Study Finds People Can Identify People's Ages Based on Body Odors
Posted on May 31, 2012
A study, published here in PLoS One, has determined that people can identify other people's ages based on their body odors. Much of this ability is based on identifying odors of elderly individuals. However, the study found that the so-called 'old-person smell' is less intense and less unpleasant than body odors of middle-aged and young individuals.
Human body odors contain chemical components and the composition of these odors changes as a person ages. To test whether people can intuitively sense these changes, the researchers, led by Johan Lundstrom of the Monell Chemical Senses Center in Philadelphia, Pennsylvania, collected body odors for testing. The body odor was collected in the form of a t-shirt with underarm pads slept in for five nights, from young, middle-aged, and elderly participants.
The underarm pads were then cut into quadrants and placed in glass jars. Odors were assessed by 41 young (20-30 years old) evaluators, who were given two body odor glass jars in nine combinations and asked to identify which came from the older donors. Evaluators also rated the intensity and pleasantness of each odor. Finally evaluators were asked to estimate the donor's age for each odor sample.
The participants were able to discriminate between the three donor age categories, and the researchers found that it was odors from the old-age group that were driving this ability. However, evaluators rated body odors from the old-age group as less intense and less unpleasant than odors from the other two age groups.
Lundstrom says, "Elderly people have a discernible underarm odor that younger people consider to be fairly neutral and not very unpleasant. 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."