Studies suggest that humans have the ability to smell disease, which researchers believe could be a mechanism designed to help healthy individuals avoid people who are contagious. A 2014 study found that the T-shirts worn by participants who had been injected with a bacterial toxin were rated as smelling worse than those worn by participants who had been injected with salt water. The researchers found that it took about four hours to activate the immune system enough to be able to smell disease and that participants whose immune systems were the most sensitive to the toxin also rated the fabric as smelling the worst.
More about humans’ sense of smell:
- About 80% of the sense of taste is thought to be determined by smell.
- Yellow fever has been found to give off a scent similar to that of a butcher shop, and research as found that men who have gonorrhea are rated as smelling less favorable than those who do not have the disease.
- The sense of smell is generally more accurate than other senses over time. For example, after three months, smells can be remembered with 65% accuracy, compared with 50% for sights.