Men's perspiration contains a substance called androstenone, a derivative of testosterone.

But when you smell it, your genes determine what you sense. Some people perceive androstenone like vanilla. For others, in smells like urine, according to research at Rockefeller University and Duke University.

Others can't smell it at all.

The study of the single gene that controls how you smell the substance will be published in the journal Nature.

For the research, 400 people were asked to smell 66 different odors at different strengths. Genetic blueprints of the participants were then checked against their responses to find the exact gene that controls how people smell androstenone.

The authors said that many animals use the scent to convey social and sexual information. It is not known how the gene variations could affect perceptions and behavior in people.