Investigating left- and right-nostril olfactory abilities with respect to psychopathy

Introduction: Evidence for olfactory lateralization is mixed, although a left-sided benefit for odor identification seems likely. Whether lateralization of function is moderated by variables such as gender and handedness has been previously explored. However, there has been no test of whether psychopathy and empathy—personality characteristics which may themselves affect lateralization and which can affect olfactory function—moderate olfactory lateralization. 

Methods: Eighty men and women engaged in mono-rhinal testing for odor threshold, identification, and discrimination ability, as well as completing standardized measures of psychopathy and empathy. 

Results and Discussion: While there was a clear left-sided benefit for odor identification and discrimination, we found no evidence that psychopathy or empathy moderated these effects. When the current data were combined with that from previous studies, we found that psychopathy was correlated with poorer odor discrimination and identification, whereas empathy was correlated with enhanced discrimination and identification, pointing to processing commonalities between olfaction, psychopathy, and empathy.