This thesis is centered around the development and application of a digital platform for passive behavioral human subject research.This platform named Behapp (https://behapp.com), developed at the University of Groningen, makes use of mobile ‘apps’ to passively record various attributes related to social and explorative behavior through the smartphones of research participants. The resulting data is detailed, objective and can be received on a longitudinal basis without active input from the participant. It is expected that such a detailed perspective on behavior may contribute significantly to our understanding of various diseases. Feeling (un) well is often closely related to one’s social and explorative behavior.An important and recurrin...