The Twins Early Development Study (TEDS) is one of the leading large-scale twin studies in the world. Starting in 1994, it has followed twins born in England and Wales throughout their childhood and adolescence and has now continued into early adulthood, with the goal of gaining better insights into the roles of genes and environment in shaping who we are. The study was founded and run by Professor Robert Plomin for 25 years and is now headed by Professor Thalia Eley.

Using birth records of twins born between 1994 and 1996, the parents of potential participants were contacted and the families invited to take part in the TEDS study. Over 15,000 pairs of twins originally signed up for the study and more than 10,000 families remain involved to the present day. The twins and their families help our research by completing questionnaires and taking part in interviews about different environmental and individual factors that might have been influencing them throughout their lives.

We have also collected DNA samples from 12,500 twins and are using them together with the rest of the data to better understand how genes affect abilities, behaviours and mental health. With the recent revolution in molecular genetics technology, TEDS data is contributing to international efforts to identify which genes play a part in influencing these attributes.

A parallel study has also been launched, the Children of TEDS, or CoTEDS, which collects data from the children of our now grown-up original cohort of twins to establish how different behaviours and traits are passed down through generations. We hope that our scientific contributions will help families, teachers, policy makers and individuals themselves better understand the challenges we face when we grow up and how to deal with them in a more effective way.

Overview Publication

Lockhart, C., Ahmadzadeh, Y., Breen, G., Bright, J., Bristow, S., Boyd, A., Downs, J., Hotopf, M., Palaiologou, E., Rimfeld, K., Maxwell, J., Malanchini, M., McAdams, T. A., Plomin, R., & Eley, T. C. (2023). Twins Early Development Study (TEDS): A genetically sensitive investigation of mental health outcomes in the mid-twenties. JCPP Advances, 3, e12154. doi: 10.1002/jcv2.12154; PMC10519737