An interesting study done by researchers in Australia says to have proven there to be a link between having a poor sense of smell and being a psychopath. The process of smelling uses the part of the brain known as the orbitofrontal cortex. The researchers found that this area of the brain tends to work 'less effectively' in those who score high in tests that measure psychopathy. A study done by Macquarie University in Sydney tested the theory that psychopathic personality disorder can be linked to impaired 'olfactory processing'. They did this by organizing an experiment that involved seventy-nine participants ranging from the ages of 19 to 21 that were previously diagnosed as 'non-criminal psychopaths'. The researchers began by administering a self-report psychopathy diagnostic test then followed up with testing the participants 'sniffing' abilities. They did this by using sixteen varied 'Sniffin' Sticks' that had familiar scents such as leather or coffee. Those who tended to have psychopathic tendencies also tended to perform poorly on the smell tests. Researchers are saying this makes sense because people with psychopathic traits tend to have decreased function in the brain's frontal lobe. Conveniently enough this is the same area of the brain that is associated with an impaired sense of smell. Researchers say this information is useful because psychopaths can try to fake their answers during psychological evaluations, so a measure of smelling ability can help make way as a new way to detect psychopathic traits.
Provided below is a link to the Levenson Self-Report Psychopathy Scale test (an example of the type questions the participants that took part in this study were asked) -
Levenson Self-Report Psychopathy Scale Test