This study reports the first behavioral genetic investigation of the extent to which genetic and/or environmental factors contribute to the relationship between the Big Five personality factors and trait emotional intelligence. 213 pairs of adult monozygotic twins and 103 pairs of same-sex dizygotic twins completed the NEO-PI-R and the Trait Emotional Intelligence Questionnaire (TEIQue). Replicating previous non-twin studies, many significant phenotypic correlations were found between the Big Five factors — especially Neuroticism, Extraversion, and Conscientiousness — and the facets, factors, and global scores derived from the TEIQue. Bivariate behavioral genetic model-fitting analyses revealed that these phenotypic correlations were primarily attributable to correlated genetic factors and secondarily to correlated non-shared environmental factors. The results support the feasibility of incorporating EI as a trait within existing personality taxonomies.

Background: The role of individual differences, including pre-morbid personality, in the development of post-stroke depression, has received relatively little attention. We undertook a cross-sectional study to investigate the relationship between pre-morbid personality and other individual differences, and depression following acute stroke.

Method: We studied 61 consecutive patients admitted to a dedicated stroke inpatient unit. DSM-IV depressive diagnoses were ascertained using the Composite International Diagnostic Interview and depressive symptoms were ascertained on the Hamilton Depression Rating Scale and the Center for Epidemiologic Studies Depression Scale. Informant-rated personality scores were obtained on the full 240-item Neuroticism, Extraversion and Openness Personality Inventory – Revised. Adaptive function was measured on the Modified Barthel Index and the Instrumental Activities of Daily Living scale. Cognitive function was assessed on the Mini-mental State Examination.

Results: An increased risk of post-stroke depression was conferred by both pre-morbid neuroticism [odds ratio (OR) 3.69; 95% confidence interval (95% CI) 1.25–10.92] and a past history of mental disorder (OR 10.26; 95% CI 3.02–34.86). There was no significant relationship demonstrated between lesion location and post-stroke depression.

Conclusions: Informant-rated pre-morbid neuroticism and a past history of mental disorder were important predictors of depression following stroke. Stroke side was not significantly related to risk of depressive symptoms following stroke.