Age-related sex differences in explicit measures of empathy do not predict brain responses across childhood and adolescence

Behavioral research indicates that human females are more empathic than males, a disparity that widens from childhood to adulthood. Nevertheless, the extent to which such sex differences are an artifact of self-report indices is unclear. The present study compared age-related sex differences in both self-report and neurophysiological measures of empathic arousal, a primary building block of empathy. Participants included sixty-five 4-17-year-old children (mean 11.5 +/- 3.5 years) who completed the Bryant Empathy Scale, and were scanned while viewing animated clips depicting people being hurt. Female participants scored higher than males on self-reported dispositional empathy, a difference that increased with age. In contrast, no sex-related differential changes were detected in hemodynamic responses or in pupil dilation, with no interaction between sex and age. Results suggest a dissociation between explicit ratings and neurophysiological measures of empathic arousal. Past observed sex differences in empathy may reflect females' greater willingness to report empathic experiences. Findings are also discussed in terms of discrepancies in the methods used to assess affective responding and how they relate to the multi-faceted construct of empathy. (C) 2012 Elsevier Ltd. All rights reserved.