The processing of the emotional signals of others is fundamental for normal socialization and interaction. Reduced responsiveness to the expressions of sadness and fear has been implicated in the development of psychopathy (Blair, 1995). The current study investigates the ability of boys with psychopathic tendencies to process auditory affect information. Boys with psychopathic tendencies and a comparison group, as defined by the Antisocial Process Screening Device (APSD: Frick & Hare, 2001), were presented with neutral words spoken with intonations conveying happiness, disgust, anger, sadness and fear and were asked to identify the emotion of the speaker based on prosody. The boys with psychopathic tendencies presented with a selective impairment for the recognition of fearful vocal affect. These results are interpreted with reference to amygdala dysfunction and components of the Integrated Emotion Systems model.

This study investigates the ability of psychopathic individuals to process facial emotional expressions. Psychopathic and comparison individuals, as defined by the Hare Psychopathy Checklist Revised (PCL-R), were presented with a standardized set of facial expressions depicting six emotions: happy, surprised, disgusted, angry, sad and fearful. Participants observed as these facial expressions slowly evolved through 20 successive frames of increasing intensity. The dependent variables were latency in responding as measured by frame and number of errors. The psychopathic individuals showed selective impairment for the recognition of fearful expressions. The results are interpreted with reference to the Violence Inhibition Mechanism model of psychopathy and the suggestion that psychopathic individuals present with amygdala dysfunction.

This study investigates the performance of psychopathic individuals on tasks believed to be sensitive to dorsolateral prefrontal and orbitofrontal cortex (OFC) functioning. Psychopathic and non-psychopathic individuals, as defined by the Hare psychopathy checklist revised (PCL-R) [Hare, The Hare psychopathy checklist revised, Toronto, Ontario: Multi-Health Systems, 1991] completed a gambling task [Cognition 50 (1994) 7] and the intradimensional/extradimensional (ID/ED) shift task [Nature 380 (1996) 69]. On the gambling task, psychopathic participants showed a global tendency to choose disadvantageously. Specifically, they showed an impaired ability to show learning over the course of the task. On the ID/ED task, the performance of psychopathic individuals was not significantly different from incarcerated controls on attentional set-shifting, but significant impairments were found on response reversal. These results are interpreted with reference to an OFC and amygdala dysfunction explanation of psychopathy.

The processing of emotional expressions is fundamental for normal socialisation and interaction. Reduced responsiveness to the expressions of sadness and fear has been implicated in the development of psychopathy (R. J. R. Blair, 1995). The current study investigates the sensitivity of children with psychopathic tendencies to facial expressions. Children with psychopathic tendencies and a comparison group, as defined by the Psychopathy Screening Device (PSD; P. J. Frick & R. D. Hare, in press), were presented with a cinematic display of a standardised set of facial expressions that depicted sadness, happiness, anger, disgust, fear, and surprise. Participants observed as these facial expressions slowly evolved through 20 successive frames of increasing intensity. The children with psychopathic tendencies presented with selective impairments; they needed significantly more stages before they could successfully recognise the sad expressions and even when the fearful expressions were at full intensity were significantly more likely to mistake them for another expression. These results are interpreted with reference to an amygdala and empathy impairment explanation of psychopathy.

This study investigated the performance of boys with psychopathic tendencies and comparison boys, aged 9 to 17 years, on two tasks believed to be sensitive to amygdala and orbitofrontal cortex functioning. Fifty-one boys were divided into two groups according to the Psychopathy Screening Device (PSD, P. J. Frick & R. D. Hare, in press) and presented with two tasks. The tasks were the gambling task (A. Bechara, A. R. Damasio. H. Damasio, & S. W. Anderson, 1994) and the Intradimensional/Extradimensional (ID/ED) shift task (R. Dias, T. W. Robbins, & A. C. Roberts, 1996). The boys with psychopathic tendencies showed impaired performance on the gambling task. However, there were no group differences on the ID/ED task either for response reversal or extradimensional set shifting. The implications of these results for models of psychopathy are discussed.

This study investigated the relationship between the inattention and impulsivity components of Attention-Deficit-Hyperactivity Disorder (ADHD) and psychopathic tendencies in children with emotional and behavioural difficulties. Teachers rated 71 children on the Psychopathy Screening Device (Frick & Hare, 2000: Frick, P. J., & Hare, R. D. (2000). The psychopathy screening device. Toronto: Multi-Health Systems (in press)), the DuPaul’s ADHD rating scale (DuPaul, 1991: DuPaul, G. J. (1991). Parent and teacher ratings of ADHD symptoms: Psychometric properties in a community-based sample. Journal of Clinical Child Psychology, 20, 245–253), and the Conners’ Abbreviated Symptoms Questionnaire (Conners, 1973: Conners, C. K. (1973). Rating scales for use in drug studies with children. Pharmacotherapy of children [Special Issue]. Psychopharmacology Bulletin, 24–84). Significant inter-correlations between teachers’ ratings of children’s inattention and impulsivity and psychopathic tendencies were found. There were significant inter-correlations between teachers’ ratings of the inattention and impulsivity components of ADHD and the Callous and Unemotional (C/UN) and Impulsivity and Conduct (I/CP) problems components of psychopathy. Further analysis revealed that the inter-correlations between these four components were mainly due to the association between the impulsivity component of ADHD and the antisocial behaviour (I/CP) component of psychopathy. The inattention component of ADHD was not related to either of the psychopathy risk measures. Equally, the distinguishing factor of the psychopathy (C/UN) was not related to either of the ADHD measures. A categorical analysis of the data revealed a higher than chance level of co-morbidity of ADHD and psychopathic tendencies.