Kids are most vulnerable to the examples they receive from their immediate caretakers (example, parents, tutors, etc.) Their immediate environment plays a more deterministic role in their behaviour than their hobbies. For example, if a kid is raised in a lovely and supporting family he/she could engage in violent videogames for fun, and not for rehearsal issues (thinking he/she is actually killing). So the early history (wether he suffer any kind of physical/psychological abuse) and the kind of family (wether they are supportive or punitive) plays a critical role in supporting previolent behaviours that videogames or other stuff migth help to develop later on.