Number and percentage of live births, by month of birth, 1991 to most recent year.

Historical chart and dataset showing U.S. birth rate by year from 1950 to 2025.

The 1970 British Cohort Study (BCS70) is a longitudinal birth cohort study, following a nationally representative sample of over 17,000 people born in England, Scotland and Wales in a single week of 1970. Cohort members have been surveyed throughout their childhood and adult lives, mapping their individual trajectories and creating a unique resource for researchers. It is one of very few longitudinal studies following people of this generation anywhere in the world.

Since 1970, cohort members have been surveyed at ages 5, 10, 16, 26, 30, 34, 38, 42, 46, and 51. Featuring a range of objective measures and rich self-reported data, BCS70 covers an incredible amount of ground and can be used in research on many topics. Evidence from BCS70 has illuminated important issues for our society across five decades. Key findings include how reading for pleasure matters for children's cognitive development, why grammar schools have not reduced social inequalities, and how childhood experiences can impact on mental health in mid-life. Every day researchers from across the scientific community are using this important study to make new connections and discoveries.

BCS70 is run by the Centre for Longitudinal Studies (CLS), a research centre in the UCL Institute of Education, which is part of University College London. The content of BCS70 studies, including questions, topics and variables can be explored via the CLOSER Discovery website.

How to access genetic and/or bio-medical sample data from a range of longitudinal surveys:
For information on how to access biomedical data from BCS70 that are not held at the UKDS, see the CLS Genetic data and biological samples webpage.

Secure Access datasets
Secure Access versions of BCS70 have more restrictive access conditions than versions available under the standard End User Licence (EUL).

The main aim of the 1970 British Cohort Study: Age 34, Sweep 7, 2004-2005 was to explore the factors central to the formation and maintenance of adult identity in each of the following domains:

• lifelong learning
• relationships, parenting and housing
• employment and income
• health and health behaviour
• citizenship and values

For the fifth edition (May 2020), a dataset and an accompanying user guide on the Dyslexia Adult Screening Test (DAST) module, which was completed as part of the 2004 survey, have been added to the study.