COM studies developmental and motivational processes that can contribute to psychosocial growth, adjustment, and well-being across the human lifespan. These include fundamental processes such as identity development, emotion regulation, personality, the satisfaction of basic psychological needs, and the quality of motivation for engaging in behaviors and pursuing goals. These processes are examined both at a general level and within specific life domains, such as parenting and education. In addition to studying psychosocial growth, we also pay attention to developmental and motivational processes that may increase vulnerability and risk of mental health problems. To better understand this darker side of human development, we collect data not only from general population samples but also from vulnerable groups. We investigate individual development as it unfolds in continuous interaction with factors from both the proximal and more distal social environment. From a transactional perspective, we consider factors within individuals’ micro-contexts (such as parents, peers, and teachers), their meso-contexts (such as the interplay between parents and peers), and macro-contexts (such as digital media and cultural influences). We conduct societally relevant research by, when possible, examining human development in light of historically changing trends in the broader society (chrono-context). Research within COM spans the entire human lifespan, with a particular focus on adolescence and emerging adulthood as key transitional periods between childhood and full adulthood. Our work is grounded in a range of theoretical frameworks, with Self-Determination Theory occupying a prominent position. We consistently seek cross-fertilization with other theories and perspectives from various strands of literature, in order to both deepen and broaden our theoretical understanding. From a methodological perspective, research within COM is highly diverse and aimed at triangulation. We focus on longitudinal research involving intensive repeated measurements across both short and long time frames. To dynamically capture people's everyday functioning, we use diary studies and experience sampling methodology. Wherever possible, we conduct experimental studies to examine the causal role of the processes under investigation, drawing both lab and field experiments, as well as intervention-based studies. We aim for a multi-informant and multi-method approach, combining self-reports from various informants with other methods such as observations, objective outcome and behavior recordings, and physiological measures (e.g., of stress and sleep). Our goal is to valorize the fundamental research conducted within COM and translate it for a broad audience and into practical applications. We aim to optimally support the motivation, engagement, resilience, and psychological well-being of children, adolescents, and (young) adults across diverse life domains (home, school, leisure). We strive for structural changes with a sustainable, growth-promoting impact, benefitting both the psychological development of children and that of their socialization figures. We are committed to excellent research and the strengthening of professional practice, driven by a strong belief in the growth potential of all people.