Identification of self through olfaction.

To study olfactory communication in humans, 100 undergraduates ranging from age 18 to 45 yr. wore freshly washed, identical T-shirts continuously for 24 hr. During this time, the participants did not bathe or shower or apply any scent producing substance to their bodies, i.e., deodorants, perfumes. Upon retrieval, each shirt was placed in an identical brown bag. In groups of 10, each participant attempted to identify the T-shirt he had worn the previous 24 hr. The task was administered separately for each individual so that no participants knew the choice by a previous colleague. Analysis shows that the participants were able to identify correctly their own shirts on the first try three-quarters of the time. Furthermore, sex, age, smoking habit of the participant, and menstrual cycle phase in the women were factors in successful outcomes.