A new study could help explain why you find the smell of a perfume so pleasing, while your friend finds it unbearable.
Researchers from Duke University found that the odor receptors in our noses don't work exactly the same from one person to another.
"There are many cases when you say you like the way something smells and other people don't. That's very common," study researcher Hiroaki Matsunami, Ph.D., an associate professor of molecular genetics and microbiology at Duke's School of Medicine, said in a statement. "We found that individuals can be very different at the receptor levels, meaning that when we smell something, the receptors that are activated can be very different (from one person to the next) depending on your genome."
For the study, published in the journal Nature Neuroscience, researchers examined 500 odor receptors taken from 20 people, each. All of the participants had very, very small variations in their DNA (just one or two amino acids, on a gene) that encode for the odor receptors. The researchers cloned these odor receptors, and then exposed the receptors to different concentrations of different smells, such as vanillin. They found that there were 27 receptors that responded to at least one of the smells. (Researchers noted that this means there are now 40 identified receptors that are activated by odors.)
Researchers found that between two people, about 30 percent of the odor receptors are different -- which Matsunami noted was actually probably on the low end.
Earlier this year, two studies in the journal Current Biology suggested that ability to smell could be in your genes. That research showed genetic associations for the ability to smell a floral scent, blue cheese, malt and apple.
Stress could also have an impact on our perceptions of scents. A Journal of Neuroscience study showed that when we're stressed, otherwise-neutral smells become less pleasant.