The Smell of Fear, or, How Donald Trump Decides Who to Fire

Scientists have long known that mammals, as well as invertebrates and fish, communicate fear through changes in their body odors. Recent studies at Rice now confirm for the first time that natural human body odors also provide information about human emotions that is detectable by other people.

Focusing on the emotions of fear and happiness, Rice psychologist Denise Chen and Jeannette Haviland-Jones from Rutgers University gathered data from university student and staff volunteers—40 women and 37 men. The subjects were asked to view excerpts from a comedy and from a film of snakes, bugs, and crocodiles that were menacing people. Afterward, they were rated on how happy or afraid they felt during the movies.

They were instructed to shower the night before the session, but to refrain from bathing or using deodorant or fragrance on the day of the session. The subjects wore gauze pads in each armpit while viewing the films. The subjects’ cotton pads were later grouped by movie and sex. One week later, the same subjects were asked twice to identify each of type of odor within six bottles, two of which contained unused cotton pads.

The researchers found that humans generally can distinguish between odors of happy people and those of fearful people, although women appear to have a greater capacity for doing so. Women in their study were able to discriminate between the odors of both happy and fearful men and women. Male subjects, on the other hand, more easily recognized the odor of happy women than happy men and the odor of fearful men than fearful women.

While women don’t necessarily have a better absolute sense of smell, earlier studies have shown they do exhibit a greater sensitivity to differences in smells than men. “Together with previous research,” Chen explains, “our findings suggest that women may be better able to perceive differences associated with emotionally and sociobiologically significant signals.”

The study’s findings also are consistent with prior findings that indicate women are better than men at making fine distinctions between the hand odors of two individuals of the same sex, and they’re better able to identify the sex of individuals based on differences in intensity of breath odors. Women also have been found to better recognize and identify synthetic commercial odors.

The researchers’ study was published in Perceptual and Motor Skills. Currently, Chen is conducting studies of other kinds of emotions and their accompanying odors as well as what may be contributing to individual differences in sensitivity to smell between men and women.