One of the other experts we consulted with, this guy named Dacher Keltner, he was big on sadness as community bonding - I think is the word he used.

Sometimes suffering is a weird attraction.

Dr. Paul Ekman, who worked in San Francisco - still does - which is where Pixar Animation Studios is, he had early in his career identified six. That felt like a nice, manageable number of guys to design and write for. It was anger, fear, sadness, disgust, joy and surprise.

The idea kind of started with me just thinking about what would be fun to see in animation, you know - what have I not seen? For some reason, I got thinking about the human body and realizing, well, I've seen, like, traveling through the bloodstream and into the, you know, stomach and things.

And in part that's good but then, like any emotion - and this is something we learned from the research as well - there are positive and negative aspects to all of these.

And usually I'm not watching the screen. I'm kind of sitting and looking off to the side, spying on people to see what they react to' cause it's - as Joe Ranft used to say, you know, animation is like telling a joke and waiting for three years to see if anyone laughs

You know there's always that kid in your class — and every class has one — the kid who draws all the time and is really good? That was not me. I was a lousy draftsman. But as soon as I figured out that I could make things come alive, like using the corners of my math book to make flipbooks, I was hooked.