The research, published in the journal Chemosensory Perception, showed that people who scored high on a test of psychopathy also had more problems with being able to tell different smells apart, not to mention identifying smells.
The study included 79 adults who didn't have a criminal background. The researchers conducted a number of experiments to test their ability to smell and tell smells apart, and also had them take a test that measured their levels of psychopathic traits like callousness, manipulation, the urge to commit criminal acts, and leading an erratic lifestyle.
"Our findings provide support for the premise that deficits in the front part of the brain may be a characteristic of non-criminal psychopaths," the researchers, from Macquarie University, said in a statement. "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."
Past research has shown that people who exhibit psychopathic traits also have impaired functioning in the brain region in charge of planning, making sure we act in a socially appropriate manner, and keeping our impulses in check, the researchers said. This front part of the brain, when impaired, has also been known to have effects on smell.
Earlier this year, a study from the King's College London's Institute of Psychiatry showed that criminals who are psychopaths also have differently structured brains from non-criminals and criminals who aren't psychopaths, Reuters reported.
Psychopaths' speech patterns may be slightly different from the rest of the general population, as well. Last year, Cornell University researchers found that psychopaths lack emotion and speak in terms of cause-and-effect when describing their crimes. Their research was published in the journal Legal and Criminological Psychology.
...psychopaths can't tell that they stink!