This questionnaire module contains questions on: freetime and cultural activities with family members (parental report); freetime and cultural activities with family members (self-report); frequency of arguments with partner, frequency of arguments of parents, subjective burden and coping; occurrence and subjective evaluation of important life transitions and developmental tasks (e.g. school enrolment, stays abroad, entering labor market, romantic relationships, change of social environment); parenting style of mother, father, partner of father, partner of mother (child report); partnership and marital status; satisfaction with sibling relationship; twin relationship: warmth, conflict, affection, hostility, rivalry; twin-specific questions for parents (e.g., dress twins alike); twin-specific questions for siblings (e.g. relationship of the twins); twin-specific questions for twins themselves (e.g. relationship to other twin).