Stashed in storage facilities dotted around Bristol is a macabre cache of bodily matter: there are 9,000 pickled human placentas in yellow plastic buckets, cardboard boxes of fingernail clippings and baby teeth, and freezers full of DNA samples, pots of frozen urine and slices of umbilical cord. There is, however, nothing sinister about this Frankensteinian collection. Together with innumerable reams of questionnaires and terabytes of computer data, it is part of the world’s longest mass study of a general population which, to date, holds detailed information on five generations of Britons — 70,000 of us in all.
The project, what’s known as a “longitudinal study”, had its genesis in 1936 with a widespread concern at the falling birth rate. In 1945, when soldiers returning from war made up for lost time, baby bust turned into baby boom. This sudden mass of pregnancies offered an unrivalled scientific and social opportunity and in 1946 a birth cohort study was established to examine in detail all the babies born in Britain in one week in March — 13,687 of them, of whom 5,362 have been followed over the succeeding decades. Further cohort studies were set up to study the babies of 1958, 1970, 1991 and 2000.
The information garnered has changed the way we live, informing everything from medical policy and education to politics. The studies are continuing and thousands of the 1946 cohort, which turns 70 this month, still respond to the study’s questions: the next role they will play, having over the years revealed much about how we are born, develop, and find our place in society, is how we die. In The Life Project the science writer Helen Pearson tells the story of the five cohorts and how their lives have impacted on almost all of us.
“Babies in the lowest social class were 70 per cent more likely to die
The questions asked of the mothers of the 1946 children were extraordinarily broad: the study co-ordinator, a 31-year-old doctor called James Douglas, wanted to know such things as whether they had their extra ration of a pint of milk a day, who looked after their husband while they were busy giving birth, how much did they spend on clothes for the baby and “corsets, brassieres and knickers” for themselves? Follow-up questions asked whether the children sucked their thumb or picked their nose and how frequent their bowel movements were.
Once the data had been amassed and collated Douglas was startled to find that babies in the lowest social class were 70 per cent more likely to die than those in the top class, and that differences in antenatal care were significantly responsible. The results timed perfectly with the formation of the National Health Service, which in 1948 subsequently enshrined free maternity care as a prerequisite for all in the hope that the state could ameliorate social inequality.
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The 1958 survey meanwhile showed for the first time that women who smoked during pregnancy increased both the likelihood of lower birth weight in their child and perinatal death. The link seems obvious now but even as late as the early 1970s, when a paper laying out the findings was published, 40 per cent of pregnant women smoked.
The cohort studies offered proof, too, of a worrying correlation between social class and academic achievement with clever middle-class children doing demonstrably better than equally clever working-class children. The divergence, the studies revealed, was apparent even in primary schools. As one newspaper headline put it: “Slow reader may lack an indoor loo.” The information was a significant driver for the Labour government’s expansion of comprehensive schools in 1965.
Other areas of public policy influenced by the studies included the effects of pollution (leading to the Clean Air Act of 1956), the sudden rise in obesity that started in the affluent 1980s, and the unexpected extent of adult illiteracy (19 per cent in 1998 having a lower reading age than 11-year-olds). Included in the plethora of unexpected data that also emerged was that women who performed well in intelligence tests as children reached the menopause later than their peers; that in many cases chronic disease had its origins in the foetus; and that social mobility actually decreased between the 1958 and 1970 cohorts.
Pearson has done a real service in explaining how wide-ranging these extraordinary and little-known studies have been. Some of the rest of the book though is less absorbing: her worthy accounts of the scientists running the cohorts and their battles with funding agencies offer a glimpse of perennial problems but can’t match the epic narrative of the cohort material. Despite the fascinating picture of how Britain has changed over the past 70 years there are too few voices in the book of the guinea pigs themselves. More would have been welcome since what they have been part of is fascinating. As one of the 1946 cohort puts it: “I wonder when we reach the pearly gates, whether there’ll be someone from the study standing there, you know, with their clipboard.”
The Life Project: the Extraordinary Story of Our Ordinary Lives by Helen Pearson, Allen Lane, 399pp, £20. To buy this book for £17, visit thetimes.co.uk/bookshop or call 0845 2712134