Information in English


Dear Visitor,


Please note: We re-structured the TwinLife homepage, and we stopped maintaining the English version, as this page is mainly adressed to the participants and the German-speaking public. For the scientific community, we installed an English documentation website, where all important information about Twinlife can be found. Up to date, this site is still under construction, but it will provide all the information you need soon.

In the following, here is some brief information about TwinLife for you. Clicking the headings will open the content.

What is TwinLife?

TwinLife is a 12-year representative behavior genetic study investigating the development of social inequality.

The long-term project has begun in 2014 and surveys more than 4,000 pairs of twins and their families regarding their different stages of life on a yearly basis. Not only social, but also genetic mechanisms as well as covariations and interactions between these two parameters can be examined with the help of identical and fraternal twins.

In order to document the individual development of different parameters it is important to examine a family extensively over the course of several years. Six important contextual points are focused on: Education and academic performance, career and labor market attainment, integration and participation in social, cultural and political life, quality of life and perceived capabilities, physical and psychological health and eventually behavioral issues and deviant behavior. The so collected data can give insight into questions concerning the development of social inequalities and will be made available to the scientific community.

Where can I find further information and a documentation of the data?

Shortly we will provide a detailed English documentation for the scientific community at! At the moment, however, the site is still under construction, and the content is still being worked on. Until completion you will find relevant documentation


How can I get the data?

Since January 2019, the data of the first household and the first telephone interview of the whole sample (4,097 twin families) are available as Scientific Use File (SUF). For scientists they are available for free (after application) at the data catalogue of GESIS where you can also find further information about the application and the content of the SUF.

The data of the further surveys will be conditioned in the upcoming years and they will be provided to reserachers. Because of this, comprehensive analyses will be possible (for example of the developmental courses of the twins).

A short Flyer containing the most important information on the data release can be downloaded here.


Please send the filled and signed data application form (please download from GESIS under "Data & Documents") via mail, fax or on the postal way to:

GESIS - Leibniz-Institut für Sozialwissenschaften
Unter Sachsenhausen 6-8
50667 Köln
Fax: ++49-221-47694-8420
Mail: (please contact if you have any questions about the application of the data, too)


The data have been anonymized, so no identification of the participants is possible. The data also have been checked upon plausibility and and consistency.