This thesis explores the subject of identity development during late adolescence (16-20 years). Three questions were asked, each related to one domain of interest; a) how do adolescents perceive and describe themselves (adolescents' self-concept), b) what do they consider important in their lives (adolescents' existential questions), and, c) how do they describe their contacts with adult people (adolescents' contacts with adults)? The thesis includes three studies and uses a multimethodological approach, comprising interviews, a personality inventory, sentence-completion tasks and questionnaires.

The results can be summarized as follows. The majority of the respondents had a positive view of themselves. An inconsistent self-concept was related to a number of negative factors. Existential questions mainly concerned one's personal future. Most respondents felt the need of adults in their lives, primarily due to adults' experience and knowledge.

The main conclusions can be summarized in four points. First, identity development during late adolescence needs to be discussed in terms of processes of integration. This term emphasizes continuity and interaction, rather than autonomy and separation, terms that have dominated this field for a long time. Second, identity development during late adolescence can be illustrated by means of expanding circles. The centre is constituted by the adolescent's picture of her/himself (i.e., personal integration), whereas the periphery consists of the adolescent's picture of her /himself in relation to other people and society at large (i.e., social integration). Third, lack of personal integration at this age level signals an undesirable developmental process. Fourth, adolescent - adult interaction is one important factor in relation to social integration. Here the adolescent learns to develop her /his interactional skills in order to regulate and balance her /his own life space in relation to others'. However, the results also suggest that opportunities for social interaction between adolescents and adults outside their families are insufficient and need to be improved.