How autistic people react to the smell of fear

Healthy individuals, upon smelling someone else's fear, begin to feel fear themselves. For people with autism, the scent has a calming effect, reports an article in the journal Nature Neuroscience.

People on the autism spectrum have difficulty reading interpersonal signals. They are less able to recognize emotions in other people's faces. Furthermore, a recent study shows that these individuals also perceive smells differently.

Autistics and the Smell of Fear

Scientists from the Weizmann Institute of Science in Israel conducted a study that found that autistic people are calmed by the smell of fear, while they are also aroused by neutral stimuli. This is different from what happens to healthy individuals.

The course of the study

The study involved volunteers with high-functioning autism, individuals who cope relatively well with everyday challenges. They first underwent a test to identify consciously perceived odors (e.g., lemon or sweat). Their results were comparable to those of the control group. The next step involved smelling sweat samples from individuals who were skydiving (fear-like odor) or exercising in a safe environment (neutral odor). The results of this test varied significantly between the volunteer groups. Those in the control group (without developmental disabilities) experienced anxiety when smelling someone else's fear-like odor. They experienced physiological changes (e.g., changes in skin conductance). Meanwhile, those with autism experienced decreased emotional tension, but were more likely to experience anxiety when exposed to the neutral odor.

Autistic people and trust in other people Subsequent experiments have shown that people on the autism spectrum are more trusting of people from whom they unconsciously sense fear. They are less trusting of those they are not afraid of. Autistic people have a well-developed sense of smell, but they interpret olfactory signals differently than people without developmental disabilities.