Fluid intelligence and empathy in association with personality disorder trait-scores: exploring the link.

There is some evidence that fluid intelligence as well as empathy may be significantly related to personality disorders (PDs). To our knowledge, no study has addressed those issues simultaneously in all 10 DSM PDs in a sample of the general population. We analysed data from 196 participants aged 20–41 from the Epidemiology Survey of the Zurich Programme for Sustainable Development of Mental Health Services (ZInEP), a comprehensive psychiatric survey in the general population of Zurich, Switzerland. We assessed the digit symbol-coding test (DSCT), the “reading the mind in the eyes” test (RMET) and the interpersonal reactivity index (IRI). Both measures of cognitive empathy (i.e. RMET and IRI perspective taking) were not related to any PD trait-score. The total PD trait-score was significantly associated with low scores on DSCT and IRI empathic concern and high scores on IRI personal distress, which indicates a dose–response relationship in those measures. DSCT was particularly related to borderline PD, IRI empathic concern to schizoid and narcissistic PDs, and IRI personal distress to avoidant PD. The proportion of variance explained in the total PD trait-score accounted for by DSCT, IRI empathic concern and IRI personal distress was 2.6, 2.3 and 13.3 %, respectively. Symptomatology and severity of PDs are related to low fluid intelligence and reduced emotional empathy as characterized by low empathic concern and high personal distress towards emotional expressions of others. Further research is needed that examines the association between cognitive empathy and personality pathology as well as potential clinical applications.