The ReSource Project is a large-scale, interdisciplinary study on the effects of mental training on the brain, subjective experience, health, and behavior. Over an eleven-month period, participants practice a variety of mental exercises aimed at cultivating attention, interoceptive awareness, perspective-taking on self and others, meta-cognition, compassion, empathy, and prosocial motivation. These exercises include meditative techniques as well as dyadic interactions. The training is divided into three modules that focus on: a) attention and mindfulness, b) socio-affective abilities (e.g., empathy and compassion), and c) socio-cognitive abilities (e.g., cognitive perspective-taking). We assessed the effects of these modules with more than 90 measures across multiple levels including neural structure and function, autonomic and hormonal responses, behavior, and subjective experience. Over the course of this talk I will highlight features of the training that pertain most directly to fear and trust. More specifically, I will discuss first results regarding the effects of the training on trusting behavior in economic games and on subjective and physiological responses to threat in a virtual environment.