Lessons from the longest study on human development

Today I want to confess something to you,

but first of all I'm going to ask you
a couple of questions.

How many people here have children?

And how many of you are confident

that you know how
to bring up your children

in exactly the right way?

(Laughter)

OK, I don't see too many hands
going up on that second one,

and that's my confession, too.

I've got three boys;

they're three, nine and 12.

And like you,

and like most parents,

the honest truth is I have
pretty much no idea what I'm doing.

I know I want them to be
happy and healthy in their lives,

but I don't really know
what I'm supposed to do

to make sure that they
are happy and healthy.

I mean, there's so many books out there
offering all kinds of conflcting advice.

It can be really overwhelming.

So I've spent most of their lives
just making it up as I go along.

However, something changed me
a few years ago

when I came across a little secret
that we have in Britain.

Its helped me become more confident
about how I bring up my own children,

and its revealed a lot about how we
as a society can help all children.

I want to share that secret
with you today.

For the last 70 years,

scientists in Britain have been following
thousands and thousands of children

through their lives

as part of an incredible scientific study.

There's nothing quite like it
anywhere else in the world.

Collecting information
on thousands of children

is a really powerful thing to do,

because it means we can compare
the ones who [let's] say,

do well at school or end up healthy
or happy or wealthy as adults

and the ones who struggle much more,

and then we can sift through
all the information we've collected

and try to work out why their lives
turned out different.

This British study --

it's actually a kind of crazy story.

So it all starts back in 1946,

just a few months
after the end of the war,

when scientists wanted to know

what it was like for a woman
to have a baby at the time.

They carried out this huge
survey of mothers,

and ended up recording the birth
of nearly every baby born

in England, Scotland
and Wales in one week.

That was nearly 14,000 babies.

The questions they asked
these women back then

are very different than the ones
we might ask today.

They sound really old-fashioned now.

They asked them things like,

"During pregnancy,

did you get your full extra ration
of a pint of milk a day?"

"How much did you spend

on smocks, corsets, nightdresses,
knickers and brassieres?"

And this is my favorite one:

"Who looked after your husband
while you were in bed with this baby?"

(Laughter)

Now, this war-time study
actually ended up being so successful

that scientists did it again.

They recorded the births of thousands
of babies born in 1958

and thousands more in 1970.

They did it again in the early 1990s,

and again at the turn of the millenium.

All together, more than 70,000 children
have been involved in these studies

across those five generations.

They're called the British birith cohorts,

and scientists have gone back
and recorded more information

on all of these people
every few years ever since.

The amount of information

that's now been collected on these people
is just completely mind-boggling.

It includes thousands
of paper questionaires,

and terabytes worth of computer data,