My research philosophy is rather reductionistic. It is based on the conviction that in order to understand ecological systems, one has to get down to the level of individuals. It is the individual that via its flexible behaviour and plastic life history traits create the patterns we observe on higher organisational levels. Accordingly, my research interest lies in the field of individual trait variation and its relevance for population and community dynamics. This philosophy is in line with the ongoing shift in population and food web ecology towards a more individual trait based approach. More specifically, I use multi-generational population experiments, behaviour and life history assays of individuals, and mathematical models to unravel how individual variation in body size, life history and behaviour affects populations and communities.