Here's the one weird sign that will tell you if someone is a psychopath
While many associate the word 'psychopath' with Norman Bates' murderous loner in Alfred Hitchcock's classic movie "Psycho", the personality disorder doesn't always result in violence. The term is commonly used as a synonym for words like 'crazy' and 'insane', even though this is inaccurate. This is one of the many misconceptions about mental illness that spreads without anything concrete behind it.
The features that psychopaths exhibit are persistent antisocial behaviour, impaired empathy, lack of remorse, as well as egotistical traits. It ends up being quite hard to identify those with psychopathic traits, even when specialists such as the Canadian psychologist Robert D. Hare popularised the categorisation in criminology with his Psychopathy Checklist.
There are actually a surprising amount of people in the world that are classified as psychopaths, with around 1% of the population diagnosed (and presumably many more undiagnosed). So, if we can potentially confuse traits of the personality disorder with common traits found in the neurotypical, how do we tell when someone is truly a psychopath?
A recent study, which originates from the journal of Chemosensory Perception, may have an answer. Given the lengthy title of 'Olfactory Abilities and Psychopathy: Higher Psychopathy Scores Are Associated with Poorer Odor Discrimination and Identification', this study has had some interesting results. As it turns out, there's one thing that psychopaths tend to lack: a sense of smell.
The researchers carried out their tests with 79 non-criminal psychopaths, seeing how well they could identify common smells such as coffee, fish and oranges. The study found that the subjects had a hard time differentiating between these smells, and the stronger their psychopathic traits were, the weaker their sense of smell would be.
"We found a relationship between psychopathy and olfactory discrimination and identification," the study read, "even after controlling for gender, age, empathy, smoking status, and craniofacial surgery/injury".
It is their belief that this is down to impairments in the frontal lobe, which is responsible for things such as decision making and social behavior, as well as processing smells. The study concludes:
"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 odour tests and may therefore be less susceptible to attempts to fake good or bad responses."
"These findings suggest that brain areas subserving higher olfactory processes—identification and discrimination—are somehow less efficient in individuals who score higher on psychopathic traits. In particular, we suggest that this relates to processing within the orbitofrontal cortex."
I've got to say, this is a little alarming to read for those of us with an ineffective sense of smell, as we may end up getting suspicious looks from anyone else who read about this correlation. But did you know that there are other ways that may suggest whether someone is a psychopath or not? This study argued it comes down to your music taste.