Above are the results from a meta-analysis examining the relation between empathy and aggression (Vachon et al., 2014) in which we concluded:

"A mixed effects meta-analysis of published and unpublished studies involving 106 effect sizes revealed that the relation between empathy and aggression was surprisingly weak (r .11). This finding was fairly consistent across specific types of aggression, including verbal aggression (r.20), physical aggression (r .12), and sexual aggression (r .09). Several potentially important moderators were examined, although they had little impact on the total effect size. The results of this study are particularly surprising given that empathy is a core component of many treatments for aggressive offenders and that most psychological disorders of aggression include diagnostic criteria specific to deficient empathic responding. We discuss broad conclusions, consider implications for theory, and address current limitations in the field, such as reliance on a small number of self-report measures of empathy. We highlight the need for diversity in measurement and suggest a new operationalization of empathy that may allow it to synchronize with contemporary thinking regarding its role in aggressive behavior."

As we thought more about current measures of empathy, we came to believe that most were limited in their coverage of the trait, failing to capture its full range. Existing measures seemed to run from indifference to empathy--the range we referenced as low to high resonance. We believed that there should be another part of the range to capture a more dissonant conception--a sort of anti-empathy. We thought this end of the empathy continuum should capture responses like sadism, scorn, and schadenfreude. So we made a scale--the Affective and Cognitive Measure of Empathy (ACME; Vachon & Lynam, 2016). The ACME consists of 36 items and yields scores for Cognitive Empathy, Affective Resonance, and Affective Dissonance; the latter two scales can be combined to yield a total affective empathy score that runs from anti-empathy through indifference to high empathy. We thought it worked pretty well:

"Across three independent samples (N = 210-708), the 36-item Affective and Cognitive measure of Empathy (ACME) was internally consistent, structurally reliable, and invariant across sex. The ACME bore significant associations to important outcomes, which were incremental relative to other measures of empathy and generalizable across sex. Importantly, the affective scales of the ACME—particularly a new “Affective Dissonance” scale—yielded moderate to strong associations with aggressive behavior and externalizing disorders. The ACME is a short, reliable, and useful measure of empathy."

Feel free to use it.

Download the Affective and Cognitive Measure of Empathy (ACME)