Age differences in social inhibition among university students and the general population

Background. Given the increased risk of socially inhibited (SI) individuals on internalizing psychopathology, insight into mean-level age and sex differences of adult SI is important since it may enhance our understanding of adaptive and maladaptive changes in SI across the lifespan. This study aimed to examine age differences in social inhibition (SI) and its underlying facets and whether these are moderated by sex. Methods. The 15-item Social Inhibition Questionnaire (SIQ15) was administered 847 undergraduate students (Mage=20.4±2.4; 72.4% women), and 2235 individuals from the general population (Mage=47.0±16.4; 50.1% women). Categorical CFA using means and variance-adjusted WSLMV estimation was fitted to replicate the previously identified three-factor social inhibition model. We estimated the differences in the latent higher order SI scores, compared the mean scores on the three latent SI facets between different age cohorts, subsamples, and sex, and investigated the moderation effect of sex on age cohort differences. Results. There were age cohort differences in SI, with highest levels in the youngest age group (