Personality Change Through Military Training in Switzerland

For many young adults in Switzerland, basic military training is a significant life event with implications for daily routines and life. Theory and some previous studies suggest that this experience also relates to people’s personality development. In the present study, we investigated the role of an 18-week basic training in the change of Big Five traits and self-esteem using a weighted control group design with n = 1,191 Swiss soldiers and n = 441 civilians at baseline ( N _total = 1,632–288 across assessments). The study spanned 54 weeks and four assessments (T1–T4). We examined baseline group differences (selection effects), group differences in change (socialization effects), and moderators of change (social investment and goals to change traits) using latent change models. At the start of their training, soldiers reported higher levels of conscientiousness and lower levels of open-mindedness than civilians. Basic training (T1–T2) was associated with greater mean-level increases in extraversion, conscientiousness, emotional stability, and self-esteem. After training (T2–T4), we found no group differences in change. In sum, our findings support the plasticity principle of personality and partly replicate previous research on military training and personality change. However, we found no evidence of social investment or change goals as moderators of change.