Dr. Cathal McCrory:

There are two cohorts in Growing Up in Ireland. There is an infant cohort of approximately 11,000 children, who were nine months old at the beginning and to whom the researchers returned when they were three years and five years and who researchers will return to at nine years. There is a childhood cohort to whom researchers first went to at nine years, then 13 years, 17 years and they are considering whether to return to them at 21 years.