One night in early March, well over a hundred people gathered together in the British Library in central London to celebrate their collective 65th birthday.
I was lucky enough to tag along.
These people, together with thousands of others living around the United Kingdom, were all born in the first week of March 1946, and they are all part of the world's longest-running study of human health.
At the time the study started, the British government was concerned about public health in the wake of World War II. And the health of children, born during a time of strict food rationing, was of particular concern.
Since their birth, the people in the study have been periodically poked, prodded and questioned by researchers. It may sound invasive, but a few awkward checkups in the teenage years aside, most of the study participants I spoke to didn't mind one bit.
Adrienne Mordan is one of many study members who has become more interested in the research as she's grown older. Today, like many in the room, she feels a sense of pride in what she has contributed. "As we get the study results, we can see sometimes they've actually influenced even governments," the 65-year-old says. "I feel very privileged to be involved with it."
Of the 5,362 babies originally enrolled in the National Survey of Health and Development, just 11 percent dropped out. Another 11 percent live abroad, and 13 percent have passed away.
The remaining group, or cohort in the lingo of researchers, is a boon to scientists around the world. Hundreds of papers have been written about the 3,000 or so cohort members. Most can be summed up in a single sentence: Early life is extremely important.
Some of the first hints of the importance of childhood came in the1960s, when researchers found to their surprise that children who performed equally on intelligence tests got different grades depending on their socioeconomic background. The finding led to education reform in Britain, while bolstering the case for programs like Head Start in the U.S.
As the cohort has aged, more and more relationships have shown up between conditions in childhood and health in later life. Some of them are downright bizarre. How well a woman scores on a cognitive test at age 8 seems to correlate to when she enters menopause, regardless of her socioeconomic background.
Diana Kuh, a scientist at the Medical Research Council and the third person to head the decades-long study, says that there's no obvious one reason for some of these correlations. She suspects that it is a cumulative effect of a lot of little things that happen early in life.
Researchers have gathered about 18,000 pieces of information on each person in the study, and they plan to gather a whole lot more as time goes one. But the scientists know it's not just about the numbers. Kuh makes it a point to write to the participants and their families, especially when they are experiencing difficult periods in their lives, or volunteering valuable information about themselves.
(This article in Nature gives more in-depth information about the study and its participants.)
The birthday party at the British Library was meant as another reward for study members. Because scientists wanted the study itself to have as little an effect on people's lives as possible, they intentionally tried to keep study members apart for most of their lives.
This year, they decided to make an exception for two reasons. First, the study is going to get more intrusive from here on out because people will undergo a battery of medical tests. If those tests turn up, say, cancer, then the study members will be told and treated. But equally important is that the scientists just wanted to say thanks for a life's work.
LYNN NEARY, HOST:
This year in London, there was a one of a kind birthday celebration. It brought together people who had never met but have shard an experience for their entire lifetimes. Sixty-five years ago in 1946, thousands of British babies, all born within a single week, were selected to be part of a study, a lifelong study. They've been under the microscope ever since.
Reporter Geoff Brumfiel was there at the anniversary event.
GEOFF BRUMFIEL, BYLINE: It's a very civilized evening here at the British Library in central London. Silver-haired men and women mingle, making polite conversation over wine and hors d'oeuvres. You wouldn't know it to look at them, but they all have something special in common.
How old are you?
UNIDENTIFIED WOMAN #1: Sixty-five on Sunday.
(SOUNDBITE OF LAUGHTER)
UNIDENTIFIED WOMAN #2: Sixty-five.
UNIDENTIFIED MAN #1: Well, we're both 65.
UNIDENTIFIED WOMAN #3: Sixty-five today.
UNIDENTIFIED WOMAN #4: Well I'm 65 too, by coincidence.
BRUMFIEL: Actually, it's no coincidence. Almost everyone in the room turned 65 this week. They were all born in 1946 and they're all part of the world's longest continuous study of human health. It began with their birth, which coincided with the birth of another great British institution: the National Health Service.
(SOUNDBITE OF VIDEO)
UNIDENTIFIED MAN #2: This new health service will be organized on a national scale as a public responsibility.
BRUMFIEL: And it was in the spirit of public health for the public good that the study was set up. The new study would follow children with the help of a doctor who didn't like sick people.
RACHEL DOUGLAS: He found they became self-centered, whiney, moany(ph), demanding, really not terribly pleasant.
BRUMFIEL: That's Rachel Douglas, the widow of James Douglas who founded the study.
DOUGLAS: So he decided, what he'd like to do, rather than trying to cure them when they got ill, was to keep them from getting ill in the first place.
BRUMFIEL: And thus began the first British birth cohort - as these things came to be known. Over 5,000 babies were enlisted with their mothers' consent. As the children grew up, most stayed in the study. Participant Nicole Barnston says it just seemed natural.
NICOLE BARNSTON: This is something that I've always accepted. It's been all my life, you know, every so often you'll have a questionnaire or you have a medical or something. And so, I've never really thought about it in a way. It's just something that happens.
BRUMFIEL: So what do you learn following people over a lifetime? Diana Kuh is the third generation of researchers to lead the study for Britain's Medical Research Council. She sums it up this way.
DIANA KUH: The most significant of findings for me is that we were the first national birth cohort study to actually have evidence that childhood really matters for adult health.
BRUMFIEL: In fact, it mattered a lot. One of the first big results was that study members born into a poor households tested worse than equally bright children born into middle-class families. The finding reshaped British education and built the case for programs like Head Start in the United States. But it doesn't stop there.
As the cohort ages, more and more correlations are appearing between early life and later health.
KUH: So, one surprising one was how well women had done on the cognitive test, even at age eight had this quite robust association with when they reached menopause. It was, it seemed to be, either an early genetic or an early hormonal effect. And that's one of the puzzles that we're still actually trying to explain.
BRUMFIEL: Now, as the cohort reaches retirement, things are starting to get really interesting. Study members like Douncan Boulton are undergoing a battery of medical tests.
DOUNCAN BOULTON: Found out a number of things like all my heart valves leak or, you know, my bone density is perhaps not as good as it should be. But, hey, the guy said it doesn't matter, so I believe him.
BRUMFIEL: The information being gathered could help scientists to better understand the aging process and governments to manage their aging populations. It's such a unique opportunity that American researchers, like Emily Murray, have traveled here just to study the cohort even though the U.S. has plenty of cohort studies of its own.
DR. EMILY MURRAY: When they're 65, you know, that's when it starts to get interesting where if you started a cohort in the 1960s, they're not old enough to have things interesting to us.
BRUMFIEL: It may seem a little macabre to be studied as you grow old and die, but many feel like Sheila Lucas.
How do you feel about being followed to the grave here?
SHEILA LUCAS: I think its fine. I'm happy to be part of the piece of research, really. It's extremely important. Oh, saying it's a duty is rather heavy handed. But it's something you said you would do and then so you do it.
BRUMFIEL: In fact, 13 percent of the cohort has already passed away and others have left the study. But plenty more remain. Again, Douncan Boulton.
BOULTON: It's nice to know there are quite a lot of people still left. You know, you might think you were the last survivor.
BRUMFIEL: Reassuring, huh?
BOULTON: Yeah, very reassuring.
BRUMFIEL: And together with researchers, they're having a great party.
(SOUNDBITE OF SINGING, "HAPPY BIRTHDAY SONG")
BRUMFIEL: For NPR News, I'm Geoff Brumfiel in London.
(SOUNDBITE OF MUSIC)
ROBERT SIEGEL, HOST:
You're listening to ALL THINGS CONSIDERED from NPR news. Transcript provided by NPR, Copyright NPR.