The terms psychopath and sociopath are often used interchangeably, but there appears to be some hesitance by researchers in the many disciplines comprising criminology to continue this trend. The problem seems to be that as research has advanced in studies of psychopathy, which is the more common of the two terms, psychopathy now commands a much more specific definition, and this is what alienates it from its estranged cousin, sociopathy. As language can serve to hinder or confound research, it is crucial that these terms take their proper place in brain science. Here, I present how the two terms are currently used in neuroscience and psychology, and suggest how research in sociopathy should progress. (C) 2013 Elsevier Ltd. All rights reserved.