Handedness and psychopathy

Objectives: The current study investigated whether psychopathic persons exh ibit a pattern of motor dominance that differs from the left-hemisphere dom inance that characterizes the majority of the population. Background: Resea rch with cognitive tasks suggests that psychopathy may be associated with a n atypical pattern of cerebral organization characterized by either left-he misphere dysfunction or decreased hemispheric asymmetry. However, studies t hat evaluate motor dominance in psychopathy have provided mixed results. Me thod: The handedness of 420 adult male inmates at a county jail was assesse d using a scale developed by Chapman and Chapman as part of their participa tion in ongoing research. Results: Psychopaths reported reduced right-hand dominance, which cannot be accounted for by differences in age, intelligenc e, or race. Conclusions: Psychopathy is associated with an increased propor tion of mixed-handedness relative to that seen in nonpsychopathic persons. This finding is consistent with theory and research suggesting anomalous ce rebral asymmetry in psychopathic offenders.