Your family was recruited because of where you were living and when you were born. Nearly 400 areas were randomly selected for the study from across the whole of the UK. In those areas, we aimed to contact the families of all the babies born between 1st September 2000 and 31st August 2001 in England and Wales, and between 24th November 2000 and 11th January 2002 in Scotland and Northern Ireland.
At that time, virtually all families in the UK received Child Benefit. The government department administering Child Benefit – called the Department for Work and Pensions – had the names and addresses of some 27,000 families with a baby born between those dates and living in those areas. The Department for Work and Pensions wrote to all of these families inviting them to take part and giving them a chance to opt out.
Around 24,000 of these families were then approached by an interviewer when their baby was around 9 months old, and 18,552 families were successfully interviewed at the first survey.
Another 692 families, who were missed initially, were added to the study at age 3. They were recruited in the same way and lived in the same areas.