The best stats you've ever seen | Hans Rosling

That was after having spent about 20 years together with African institutions studying hunger in Africa.

So I was sort of expected to know a little about the world, and I started, at our medical university—Karolinska Institute—an undergraduate course called Global Health.

But when you get that opportunity, you get a little nervous.

I thought these students coming to us actually have the highest grade you can get in the Swedish college system,

so I thought maybe they know everything I'm going to teach them about, so I did a pretest when they came.

One of the questions—from which I learned a lot—was this one: 'Which country' has the highest child mortalityThe state of being subject to death of these five pairs?'

And I put them together so that in each pair of countries, one has twice the child mortality of the other.

And this means that it's much bigger—the difference—than the uncertaintyThe quality of being uncertain of the data.

I won't put you to the test here, but it's Turkey, which is high, as there: Poland, Russia, Pakistan, and South Africa.

And these were the results of the Swedish students.

I did that so I got the confidence interval, which was pretty narrow, and I got happy, of course, at one point: eight right answers out of five possible.

That means that there was a place for a professor of international health and for my course.

But one late night, when I was compiling the report, I really realized my discovery:

I have shown that Swedish top students know statistically significantly less about the world than the chimpanzees,

because the chimpanzee would score half right if I gave him two bananas—with Sri Lanka and Turkey—they would be right half of the cases.

But the students are not there.

The problem for me was not ignorance; it was preconceived ideas.

I did also an unfair, unethicalNot morally correct study of the professors of the Karolinska Institute—that hands out the Nobel Prize in Medicine—and they are on par with the chimpanzee there.

So this is where I realized that there was really a need to communicate about the data—or what's happening in the world—and child health, obviously.

Every country is very well aware, so we did this software, which displays it like this: every bubble here is a country.

This country over here is China, and this is India.

The size of the bubble is the population, and on this axis here,

I put fertility rate, because my students—what they said when they looked upon the world—

and I asked them, 'What do you really think about the world?'—well, I first discovered that the textbook was Tintin, mainly, and they said, 'The world is still we and them.'

And 'we' is the Western world, and 'them' is the Third World.

And what do you mean with 'Western world'?

I said.

Well, that's long life in small family, and 'Third World' is short life in large family.

So this is what I could display here: I put fertility rate here—number of children per woman: 1, 2, 3, 4—up to about eight children per woman.