Objective: To investigate the relationship between psychological constructs related to professional and research integrity and moral reasoning among medical students.
Methods: Medical students, 2nd-year (n = 208, 85.6% of 243 enrolled students), answered the moral reasoning test-defining issues test 2 (DIT2) and the Machiavellianism and Paulhus socially desirable responding (SDR) scales.
Results: Students had the highest score on the post-conventional schema of moral reasoning (mean +/- standard deviation, 35.2 +/- 11.6 of a possible 95) compared with personal interest (27.2 +/- 12.3) and maintaining norms schemae (29.2 +/- 11.5; P < 0.001, repeated-measures anova). Female students scored higher than their male collegues on post-conventional moral reasoning (37.6 +/- 11.0 versus 31.2 +/- 22.4, P < 0.001, independent-sample t-test). Of all 4 Machiavellianism subscales students scored highest on deceiving, where female students scored higher than their male colleagues (24.5 +/- 4.2 versus 22.9 +/- 5.1 of a possible 30; P = 0.037, independent-sample t-test). Female students also scored higher on the impression management subscale, whereas their male colleagues scored higher on the self-deception subscale of the Paulhus SDR scale. Moral reasoning scores were associated with cynicism, deceiving and flattering Machiavellianism scores, but not with Paulhus SDR scores. Multiple regression analysis showed the Machiavellianism amorality score as a significant negative predictor (beta = -0.183, P = 0.017) and female sex as a positive predictor (beta = 0.291, P < 0.001) for the post-conventional schema score on the DIT2. The Machiavellianism flattering score was a significant negative predictor for the personal interest schema score (beta = -0.215, P = 0.006).
Conclusions: Although moral reasoning is generally seen as independent of variables related to personality, our study indicated that Machiavellianism, especially its amorality and flattering subscales, were associated with moral reasoning. These results have important implications for teaching ethics and the responsible conduct of research in different cultural and socio-economic settings.