My favorite go-to cohort studies have been the Grant Study of the Harvard class of 1938-44, and the Adverse Childhood Experiences (ACE) test, because the ideas are well-tested and condensed into instantly employable actions. This new book, The Life Project: The Extraordinary Story of 70,000 Ordinary Lives by Helen Pearson is based on a series of very large sample size cohorts in England starting in March 1946 when 17,515 babies born that week have been interviewed periodically up to the present.
Other cohort studies have followed in 1958, 1970, 1991, and 2000. There are other longitudinal cohort studies that have been attempted both in England and in the United States that are larger and more comprehensive, but they failed through complications and lack of sufficient financial support. One thing this book makes clear is that with these huge studies it is absolutely essential to have the wholehearted support of the subjects and steady support by the financial backers. This is huge science which needs money to make any progress, and as it is socially invasive into the privacy of the subjects it is necessary to maintain perfect confidentiality with the data and delicate propriety in the social relationships. The outcomes from these studies have improved English society in a way that positively impacts all of its citizens and the people of the whole world too. Because of these longitudinal studies we all, policy makers included, have a better idea of the causes and effects of the way people’s lives unfold, and thus how to treat other people in better ways.
With so much they have discovered it was with shock and chagrin that I read on page 304, “There are currently about 3,000 study members left … and there will be just 1,400 left by the time they are eighty-four and just 300 around to celebrate their hundredth birthday in 2046 … at some point it won’t make scientific sense to keep collecting the data any more. There will be too few surviving members for the study to have any statistical power and therefore to produce meaningful results.” That is just plain wrong in my view; the 300 who survive to age 100 from the original 17,515 are the ones who have clearly done everything right and almost nothing wrong, or they wouldn’t have survived. They are the most valuable people of in all the world, and should be studied in the greatest detail. What kinds of things did they do, and what kinds of things did they avoid, and what were their motivations to stop doing dangerous things and start doing the right things? Is skiing a good sport? Is hiking in remote places a good idea? How about swimming and diving? What modes of transportation did they choose: bus, car, trolley, bicycle, motorcycle? How much did they smoke, drink alcohol, tea, coffee?
The studies probed into questions like that, but the final answers won’t be in until all of them have died. Also, the various types of treatments they are getting at age seventy may greatly affect how well they are doing at one hundred. Only longitudinal cohort studies can give definitive answers to those kinds of questions. One thing is obvious from these studies: to live a long healthy life it is best to live modestly and to be around kind, loving people from beginning to end. And as much as you can:
Live long and participate.