Introduction
This document has been prepared to accompany the second deposit, with the UK Data
Archive at the University of Essex, of data from the most recent follow-ups of two
continuing, multidisciplinary, national, longitudinal studies - the National Child
Development Study (NCDS) and the 1970 British Cohort Study (BCS70). The
follow-ups took place between November 1999 and September 2000, and it is
noteworthy that this was the first time that both cohorts had been surveyed at the same
time. They were designed and implemented jointly by the Centre for Longitudinal
Studies of the Institute of Education, University of London (CLS), and the National
Centre for Social Research (NatCen), on behalf of the Joint Centre for Longitudinal
Research. The work was mainly funded by the Economic and Social Research
Council (ESRC), but important contributions were also made by a number of
government departments, and by the Basic Skills Agency.
NCDS and BCS70
The National Child Development Study (NCDS) started life as the Perinatal Mortality
Survey and examined the social and obstetric factors associated with stillbirth and
infant mortality among over 17,000 babies born in Britain in the week 3-9 March
1958. Since this first study the whole cohort have been surveyed on five other
occasions in order to monitor their health, education, social and economic
circumstances. These surveys were carried out in 1965 (age 7), 1969 (age 11), 1974
(age 16), 1981 (age 23) and 1991 (age 33). As part of the 1991 survey, a special study
was also undertaken of the children of one third of the cohort members, including
assessments of the behaviour and cognitive development of approximately 5,000
children. There have also been surveys of sub-samples of the cohort, the recent
occurring in 1996 (age 37) when information was collected on the basic skills of a
representative sample of 10 per cent of cohort members.
The 1970 British Cohort Study (BCS70) was designed along similar lines to the
NCDS, surveying over 17,000 babies born in Britain in the week 5-11 April 1970.
Since the birth survey there have been four other major data collection exercises in
order to monitor their health, education, social and economic circumstances. These
were carried out in 1975 (age 5), 1980 (age 10), 1986 (age 16) and 1996 (age 26). As
in NCDS, sub-samples have been studied at various ages: for example at age 21,
paralleling the NCDS survey at age 37, a 10 per cent representative sample was
assessed for basic skills difficulties.
From their original focus on the circumstances and outcomes of birth, the two cohort
studies have broadened in scope to map all aspects of health, education and social
development of their subjects as they passed through childhood and adolescence. In
later sweeps, the information collected has covered their transitions into adult life,
including leaving full-time education, entering the labour market, setting up
independent homes, forming partnerships and becoming parents.
The latest rounds of data collection for NCDS and BCS70 took place in 1999/2000
when NCDS cohort members were aged 41/42 and BCS70 cohort members were aged