Okay. Okay. You're listening to Radio Lab. On New York Public Radio. Public Radio.

Public Radio. W. N. Y.C. Recently, we interviewed a guy named Stephen Johnson who wrote a book.

And he tells this story of how the book came about.

There was one specific event, actually, that really kind of triggered it, which is that I tried a biofeedback experiment.

He had found a place where he could get hooked up to a bunch of sensors and probes and then see what was happening inside his body in real time.

So I went in, having been kind of curious about this and tried it out, and it's kind of a therapeutic environment where there's kind of a doctor who sits there and talks to you.

It's a bit like going to a shrink.

And we started this session, and there's a little screen, and you see this little line kind of scrolling along.

And initially it's very even kind of flat line.

And after about a minute or two of talking, the doctor actually said, you know, your adrenaline system seems very well regulated.

Like a good thought.

Thank you very much.

Thank you.

I've always suspected that it was.

And then for some reason, about a minute or two after that, I decided, as I sometimes do, that I would make a joke. And so I tossed out some stupid little joke about something. And instantly, a huge spike appeared on the screen. There was this giant kind of surge of adrenaline that had been released in my body. And we both kind of turned and looked at the monitor and said, whoa, what was that?

And then at the end of this session, we talked for about 30 minutes and he gave me this printout of the whole session.

And it was effectively a chart of my attempts at humor.

This flat line interrupted by six spikes of jokes, you know, successful or otherwise, that I tried to make.

And I looked at that and I thought of all the times over the years that I had found myself, you know,

making borderline inappropriate jokes in situations where a joke was probably not the appropriate thing to do when I teach, you know, compulsively making jokes to get laughs from the students.

And I thought, somehow, years ago, I set up this little circuit in my head that I guaranteed me this little jolt of adrenaline every time I made a joke.

And I felt kind of like a drug addict more than a funny guy.

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