Genetic and social causes of life chances. Establishing a genetically informative, longitudinal study of the life course and individual development (TWINLIFE)

• Applicants: Professor Dr. Christian Kandler; Dr. Bastian Mönkediek; Professor Dr. Frank M. Spinath
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology ; Empirical Social Research
• Term: since 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 220286500

The study of mechanisms and underlying processes shaping people’s life chances has become an interdisciplinary endeavor. TwinLife contributes to this field by combining research approaches from different disciplines (Sociology, Psychology, Human Genetics) and examining the developmental sources of social inequalities over the life course, taking genetic and social forces as well as their interplay into account. Meanwhile, the core project has been flanked by several satellite projects, such as TwinSNPs (project number: 428902522) and TECS (project number: 458609264), which enrich the longitudinal twin family design by molecular genetic and epigenetic information. This allows a more in-depth investigation of the nature-nurture interplay in the stabilization of inter-individual differences and in the differential intra-individual development. Accordingly, the different mechanisms underlying gene-environment interactions and transactions can be disentangled. Currently, the project has successfully provided data from four face-to-face interviews and individual tests as well as three telephone interviews and additional pandemic-related questionnaires for use by the scientific community. The fourth telephone interview wave has been finished and the last face-to-face interviews in the households have just begun. Based on the core project alone, several inter-disciplinary and impactful papers have been published in recent years. The increasing age of twins allows more and more levels of perspectives, which include information on new individual developmental transitions, such as starting a family of their own. Data from children of twins and an increasing number of twins’ partners enrich the empirical spectrum. In the last funding period, TwinLife’s complete cross-sequential design can unfold its full potential for investigating the development from ages five to ages 31. With this complete design, it will be possible to disentangle age effects from cohort and time effects. The design of TwinLife combined with its continuing collection of longitudinal information on behavioral traits and environmental variables, including additional information on the immediate effects of the coronavirus pandemic on participants’ lives, will tremendously extend the scope of analyses with TwinLife data. This will enhance our understanding of the causes and processes underlying the development of multi-dimensional social inequalities over the life course.

• DFG Programme: Research Grants