Sex differences in Cloninger's temperament dimensions--a meta-analysis.

There have been many comparisons between men and women on psychological characteristics and personality. The Tridimensional Personality Questionnaire and Temperament and Character Inventory developed by Cloninger are used to measure the following temperament dimensions: novelty seeking, harm avoidance, reward dependence, and persistence. Studies using these scales in healthy (nonclinical) populations have reported varying results on sex differences, but there is no meta-analysis of the topic. In this study, meta-analytic methods were used to estimate sex differences in these temperament dimensions and to study the effect of mean age of the sample and location of the study (Asia/other) on possible differences. Studies on healthy populations were systematically collected; the required minimum sample size was 100. The search resulted in 32 eligible studies. Consequently, women scored higher in reward dependence (pooled effect size; Cohen's d = -0.63; z test, P value < .001) and harm avoidance (d = -0.33; P < .001). There were no differences in novelty seeking (d = -0.04; P = .29) or in persistence (d = -0.02; P = .62). The sex difference in reward dependence was significantly smaller in Asian studies. This study was the first one to pool studies on sex differences in Cloninger's temperament dimensions. Women scored consistently higher in harm avoidance in the studies included. Together with similar sex difference found in related traits (eg, depression), this finding supports the validity of this temperament dimension. The given data on sex differences should be taken into account in future studies using these instruments.