To illuminate individual differences in the development of attention-deficit hyperactivity disorder (ADHD) symptoms in the general population, psychometric measures are needed that can capture general population-level symptom variation reliably, validly, and comparably from childhood through to the transition to adulthood. The ADHD subscale of the…

Multifinality, equifinality, and fanning are important developmental concepts that emphasize understanding interindividual variability in trajectories over time. However, each concept implies that there are points in a developmental window where interindividual variability is more limited. We illustrate the multifinality concept under…

Adolescents navigate the transition into young adulthood through their pursuit of developmental goals. While societal expectations and institutions provide normed paths to adulthood by shaping decisions on goal identification, individuals take various routes to attain adult-status through different goal prioritization. Using longitudinal data from…

Current theories of loneliness posit that biases in social information processing play a key role in the development and maintenance of loneliness. However, this assumption has rarely been tested in longitudinal research in adolescence. The current study concentrated on two constructs associated with such biases, that is, fear of negative…

First-order theory of mind (ToM) development has shown to conform to a Guttman scale, with desire reasoning developing before belief reasoning. There have been attempts to test for internal consistency and scalability in advanced ToM, but not over a broad age range and only with a limited set of tasks. This 2-year longitudinal study (N = 155;…

Listening to speech in a noisy background is difficult for everyone. While such listening has historically been considered mainly in the context of auditory processing, the role of cognition has attracted considerable interest in recent years. This has been particularly true in the context of life-span research and the comparison of younger and…

Prediction from early development to later achievement has the potential to improve clinical and educational service delivery as well as to inform developmental theory. In this longitudinal study, we asked how well can educational achievement measured in the final year (Grade 9, age 15) of compulsory education--both overall and for outcomes in the…

Many interventions are characterized by repeated observations on the same individuals (e.g., baseline, mid-intervention, two to three post-intervention observations), which offer the opportunity to consider differences in how individuals vary over time. Effective interventions may not be limited to changing means, but instead may also include…