Family and Youth Research

Longitudinal survey regarding families with twins (TwinLife)

How does social inequality come about? And how do genes and environmental factors interact? To clarify these and other questions, the interdisciplinary TwinLife study surveys over 4,000 twin couples living in Germany and their families over several years on different areas of life.


Annual survey of 4,000 pairs of twins and their families by means of visits at home (CAPI, CASI, PAPI) alternating with telephone interviews (CATI). In addition to the twins themselves, the parents (as well as step parents) and possibly existing sibling(s) of the twins as well as the older twins and their partners are interviewed. In total, about 18,000 people are interviewed annually.


Bielefeld University, Saarland University

Project period

2016 - 2021


Family and Youth Research
Research on Education and Lifelong Learning
Social Security Research