Paul Ekman: It takes a poet to be able to express in words what a moment in expression can convey. And what the face tells you is, that's what's happening right at the moment. This person's about to fight. This person is finding things very distasteful and offensive. Or right at the moment, we're having a great time. And you know that instantly, and you know that without words. And when you, the perceiver, see it, you don't necessarily translate it into words. You just know it. You feel it.

[applause]

Narrator: Paul Ekman realised that our facial expressions are actually a powerful way to let others see what we are feeling.

Paul Ekman: A theater like this wouldn't work if you couldn't, at the back [? of the globe, ?] be able to distinguish each of the emotions. And that's just what our research found. But the most long distance transmitter of all is the smile. You can recognize the smile at 70 or 80 meters away— just about the distance that you could throw a rock or a spear.

[drums, chanting]

Narrator: 30 years ago, Paul Ekman traveled to Papua New Guinea. The work he did there was to become a landmark study of facial expressions.

The young psychologist went to live with the last remaining Stone Age culture on Earth.

Paul Ekman: In 1967 and '68, I worked in the highlands of New Guinea, which at that time had had no contact— really, virtually no contact with the outside world. Most people I studied, I was the first or second outsider they had seen. And they had never seen a photograph, a magazine, a mirror, television, film— nothing.

Narrator: Paul Ekman wanted to know whether the facial expressions used by people in the industrialized world were different from the expressions of these tribes. In other words, do facial expressions change as societies develop? Or are they fixed and universal?

Paul Ekman: I did two kinds of studies with them. I showed them photographs and I asked them to point to the one that fit a particular story. Point to the one where the person is angry— about to fight. Point to the one where he's just learned his child has died.

And then I asked them to be actors and to show me their expression. If a child had died, show me what your face would look like. If you're about to fight, show me what your face— and I found exactly the same thing I had found elsewhere.

Narrator: Muscle for muscle, the facial expressions this ancient, isolated culture used were the same as our own. Ekman went on to suggest that these universal expressions revealed a simple set of core universal human emotions— the basic ingredients of our entire emotional repertoire.

The six basic facial expressions he identified were those of happiness, sadness, disgust, surprise, anger, and fear.