The Generations and Gender Survey (GGS) is the main product of the GGP. It is a cross-national panel survey on life-course and family dynamics of individuals aged 18-79 years. The GGS tracks the experiences and changes that individuals go through in their personal lives, such as leaving the parental home, union formation and dissolution, parenthood, and the opportunities and challenges individuals face in their lives. The GGS uses a multidisciplinary approach in its questionnaire, incorporating social psychology, economics, sociology, and epidemiology. The questionnaire is designed to explore the complexities of family life, demographic behavior, and socio-economic influences on individuals, families, and households. This approach enables empirical testing of theories from multiple disciplines and considers the various societal levels influencing demographic behavior.