Vocational Interest Development in Adolescence—Integrating Insights about Normative Change, Stability, and Influencing Factors

Vocational interests are significant predictors for various life outcomes, educational decisions, and occupational choices. They are frequently assessed in practice through the application of interest inventories and used by vocational counselors to guide career-related decisions of students and jobseekers. In research, vocational interests are seen as relatively stable dispositions that develop over multiple years. Due to their stability and their impact on people’s everyday life’s, vocational interests are often included in models of individual differences. It is assumed that they describe patterns of persons general motives that are part of their personality. Theories about vocational interests suggest that they begin to develop over the course of adolescence—stability is assumed to increase and changes in interest intensity are expected. However, more empirical evidence is needed as current studies mainly focus on the description of vocational interest development in later life phases, such as the transition from late adolescence to young adulthood. Empirical studies that capture early life phases of development, such as the time period of late childhood and early adolescence (ages 11 to 14), are scarce. In addition, relatively little is known about possible factors that might influence the development of vocational interests. It is suggested that differences in personality characteristics and external factors could lead to differences in developmental trajectories. The aim of the current dissertation was to do a comprehensive investigation of the development of vocational interests over the course of adolescence (ages 11 to 18). The development of interest stability, intensity, and gender differences was investigated. It was assumed that vocational interests increase in their stability over the course of adolescence (ages 11 to 18). Interest intensity was assumed to decrease from late childhood to early adolescence (ages 11 to 14) and to increase from middle to late adolescence (ages 15 to 18). Gender differences in vocational interests were assumed to increase from late childhood to early adolescence (ages 11 to 14) and being relatively stable afterwards. Besides these overall aims, the three studies included in the current dissertation focused on individual and contextual factors that could influence the development of vocational interests. It was assumed that personality characteristics are associated to vocational interest profile stability and that the engagement in leisure-related activities could influence the development of vocational interests. In all studies, vocational interests were measured based on Hollands (1997) RIASEC model. The first study investigated the development of vocational interests over the course of adolescence. Besides examining mean-level change, gender differences in mean levels, and re-test correlations of vocational interests, the study focused on dispositional and situational components of vocational interests. The investigation was inspired by recent theories, which assumed that vocational interests are dispositions that also consist of situation susceptible components. Data was used from a large-scale longitudinal sample (N = 3,876), where students from low and middle track schools in Germany were annually followed from fifth to eight grade (mean ages 11 to 14). The results suggest that vocational interests became more stable over the three-year period, as indicated by increases in re-test correlations for four of six interest dimensions. In addition, mean levels of vocational interests decreased descriptively from late childhood to early adolescence for all interest dimensions, except Social interests. Gender differences in mean levels were already large in terms of effect sizes around age 11 and further increased over time for all interest dimensions, except Artistic interests. Results from latent state-trait analysis suggest that vocational interests consist of both, stable and situation susceptible components. However, the proportion of the stable components increased over time. The second study investigated the profile stability of vocational interests and its relation to personality traits, cognitive abilities, and gender. It was proposed that differences in individual characteristics could lead to differences in profile stability. The study investigated the research question in four different life phases: late childhood to early adolescence (ages 11 to 14), middle adolescence (ages 14 to 15), late adolescence to young adulthood (ages 17 to 23), and a longer time period over the course of young adulthood (ages 22 to 34). Data was used from four, previously conducted, large-scale longitudinal studies. Each life phase was consequently covered by a different sample from a different study. All the samples included students that lived in Germany. The results suggest that vocational interest profiles were moderately stable during the three-year time period from late childhood to early adolescence (ages 11 to 14) and highly stable during the one-year time period during middle adolescence (ages 14 to 15), the six-year time period from late adolescence to young adulthood (ages 17 to 23), and the twelve-year time period over the course of young adulthood (ages 22 to 34). Indicators of profile stability significantly varied between persons in each of the four life phases, suggesting that profile stability differed across participants. Gender was related to differences in profile stability in all life phases, with girls and women having significantly more stable profiles compared to boys and men. Associations of profile stability to personality traits and cognitive abilities were rather small. Consistent relationships were found for verbal cognitive abilities and the personality trait Extraversion, with higher scores being related to more stable vocational interest profiles. The third study investigated the impact of engaging in unstructured out-of-school time science activities, such as reading a science book, watching a science TV show, or researching on the internet about science, on the development of various constructs, including vocational interests. In line with theories about interest development, it was assumed that the engagement in unstructured out-of-school time science activities could foster the evolvement of vocational interests, as they possess advantageous properties for the initiation of situational interest. Data was used from a large-scale longitudinal sample (N = 2,655), where students from different school tracks in Germany were followed over three time points from ninth, eleventh to twelfth grade (mean ages 15, 17, and 18). Based on an outcome-wide longitudinal design for causal inference, the impact of unstructured out-of-school time science activities on the development of vocational interests was investigated. To account for self-selection effects, numerous confounder variables, such as pretests of vocational interests, other motivational variables, and ability-related constructs, were included in the analysis. The results suggest that the engagement in unstructured out-of-school time science activities had a robust influence on Investigative vocational interests, but not on the remaining interest dimensions. The findings on interest stability, intensity, and gender differences over the course of adolescence (ages 11 to 18) were integrated from the three empirical studies. The findings suggest that stability of vocational interests increased over the course of adolescence. Interest intensity decreased from late childhood to early adolescence and increased from middle to late adolescence, as shown by changes in mean levels. Gender differences increased over the course of late childhood and early adolescence, as indicated by increasing mean levels between girls and boys. Deviations from the proposed general trends in interest stability, intensity, and gender differentiation are described in the general discussion. Findings of the three empirical studies are summarized and discussed regarding their implications for vocational interest development. It is proposed that experiencing activities can initiate the development of vocational interests over the course of adolescence. Practical implications, limitations, and an outlook for future research are provided at the end of the general discussion section