BackgroundForming one’s identity is thought to be the key developmental task of adolescence, but profound changes in personality traits also occur in this period. The negotiation of complex social settings, the creation of an integrated identity, and career choice are major tasks of adolescence. The adolescent, having to make choices for his or her future, has not only to consider his or her own aspirations and interests but also to possess a capacity for exploration and commitment; in fact, career commitments can be considered as a fit between the study or career that is chosen and personal values, skills, and preferences.MethodsThe objective of the study reported here was to investigate the role of identity on profile of interests; the relation between identity and decisional style; the correlation between identity, aptitudes, interests, and school performance; and the predictive variables to school success. The research involved 417 Italian students who live in Enna, a small city located in Sicily, Italy, aged 16–19 years (197 males and 220 females) in the fourth year (mean =17.2, standard deviation =0.52) and the fifth year (mean =18.2, standard deviation =0.64) of senior secondary school. The research lasted for one school year; the general group of participants consisted of 470 students, and although all participants agreed to be part of the research, there was a dropout rate of 11.28%. They completed the Ego Identity Process Questionnaire to measure their identity development, the Intelligence Structure Test to investigate aptitudes, the Self-Directed Search to value interests, and General Decision Making Style questionnaire to describe their individual decisional style.ResultsThe data showed that high-school performance was positively associated with rational decision-making style and identity diffusion predicted the use of avoidant style. Interests were related to identity exploration; the differentiation of preferences was related to identity commitment; investigative personality correlated with the rational style and negatively with the spontaneous style and high levels of school performance; and social personality correlated with the use of the spontaneous style and the intuitive style, a high-profile identity, and identity exploration.ConclusionIntervention in the development of the identity process proves to be fundamental for increasing aptitudes and improving school performance, and, above all, for broadening the diversification and coherence of interests and improving the decisional process.