Affective and interpersonal expression in young adults during simulated interviews: implications for mental health research

Background Simulated interviews could provide behavioral information for young-adult mental-health research, including studies of social-evaluative anxiety. Their value depends on reliable observer impressions and interpretable links to participants’ self-reports. We examined personality expression, affective communication, self-observer correspondence, and competence impressions in emerging adults. Methods Two video-interview protocols were administered to participants aged 18–23 years: an occupationally framed protocol ( n = 55 ) and a broader personality-oriented protocol ( n = 33 ); 30 participants completed both. The protocols covered parallel HEXACO-related domains but differed in both framing and question content. Participants completed HEXACO self-reports and selected one of five valence-arousal categories after each response. Four observers rated personality expression, affective communication, and competence. We distinguished focused domain-matched tests from secondary question-level tests and exploratory correlation matrices, reported 95% confidence intervals, used permutation tests, and controlled the false-discovery rate within analysis families. Results Self-reported HEXACO scores were similar across protocols except for lower Agreeableness in the broader protocol (mean difference = − 0.23 , 95% CI [ − 0.35 , − 0.12 ] , q = 0.004 ). Global valence was more positive in the broader protocol (mean difference = 0.30 , 95% CI [ 0.15 , 0.45 ] , q < 0.001 ), whereas the arousal difference was uncertain. Reliability was heterogeneous: personality and competence ICCs ranged from 0.27 to 0.65 and 0.35 to 0.64 in the occupational protocol and from 0.33 to 0.58 and 0.22 to 0.73 in the broader protocol. Question-level affect ICCs were approximately 0.00 to 0.60 and − 0.91 to 0.03, respectively. Occupational self-observer correlations for Extraversion and Agreeableness survived correction; no broader-protocol personality correlation did. Strong same-observer personality-competence associations survived correction in both protocols, but broader-protocol affect-competence associations did not. Conclusions Affective reports differed between protocols, but question content also differed, precluding a pure context effect. Observer-rating reliability and self-observer correspondence identify conditions for future mental-health studies pairing simulated interviews with validated symptom and functioning measures.