Welcome at the website of the Developmental Psychology group! The main objectives of our research are (1) to gain an insight in normal human psychological development and (2) to examine which factors and processes may affect individuals’ optimal and psychopathological functioning throughout the life span. We study a broad range of positive and adaptive developmental outcomes, such as optimal learning, persistence, vitality, and self-esteem, as well as negative developmental outcomes, such as depression, perfectionism, relational aggression, and eating disorders. We investigate how the social environment, including parents and teachers, can promote or inhibit these developmental outcomes. Particular attention is paid to the processes, such as motivational processes, goals and aspects of identity development, that may explain the impact  of the social environment on  these developmental outcomes. These themes are approached from diverse theoretical perspectives, including separation-individuation theory,  identity theory, self-determination theory, achievement goal theory, and social domain theory. The research in our group has focused primarily on the developmental period of adolescence, but recently we also started to study the development of children in primary school, emerging adults, adults, and elder people. In our research we rely on a diversity of research designs, methods, and statistical techniques. Apart from correlational studies , we use experimental designs and qualitative studies. We have a particular preference for longitudinal research because such research is ideally suited to map out the often complex and dynamic processes of human development.