Psychopaths Have Impaired Sense of Smell

A sizeable number of people amongst us are psychopaths.  That could be a dangerous and scary prospect. However, this personality disorder is very difficult to identify and spot as the psychopaths appear normal though they lack the sense of right and wrong. Focusing on this disorder, the researchers from the Macquarie University in Australia conclude that, "a poor sense of smell may be a marker for psychopathic traits."

According to the study that is being published online in Springer's Journal Chemosensory Perception, the people with psychopathic tendencies have an impaired sense of smell that refers to the inefficient processing in the front part of the brain.

This personality disorder is accompanied by callousness, manipulation, sensation-seeking and antisocial behaviors, traits which may also be found in otherwise healthy and functional people.

Prior to this, studies have linked psychopathic traits with impaired functioning in the front part of the brain that plays a major role in planning, impulse control and acting according to the norms. And a dysfunction in these areas in the front part of the brain is linked to an impaired sense of smell.

The research was conducted by Mehmet Mahmut and Richard Stevenson who analyzed whether a poor sense of smell was linked to higher levels of psychopathic tendencies. They worked on 70 non-criminal adults living the community. Initially they accessed their olfactory ability as well as the sensitivity of their olfactory system. Later they also measured subjects' levels of psychopathy, looking at four measures: manipulation; callousness; erratic lifestyles; and criminal tendencies. They tried to see how far these subjects emphasized with other people's feelings.

On analyzing these subjects the researchers noticed that, "Individuals who scored highly on psychopathic traits were more likely to struggle to both identify smells and tell the difference between smells, even though they knew they smelled something. These results show that brain areas controlling olfactory processes are less efficient in individuals with psychopathic tendencies."

The authors conclude: "Our findings provide support for the premise that deficits in the front part of the brain may be a characteristic of non-criminal psychopaths. Olfactory measures represent a potentially interesting marker for psychopathic traits, because performance expectancies are unclear in odor tests and may therefore be less susceptible to attempts to fake good or bad responses."