I went to a Cafe Scientifique at the Photographer’s Gallery near Leicester Sq. last night, where this was one of the questions posed (rhetorically) by the guest speaker.

Lewis Wolpert was the speaker in question. He’s an intriguing chap and gave an entertaining if rather short talk on the biology of belief.

The answer to the cats question, incidentally, is that they lack any concept of physical cause and effect (there’s the whole opposable thumbs thing too, of course).

The turnout was good, with some audience members left standing. A bit of added excitement was supplied by having a BBC camera crew present. I pouted, stroked my chin and nodded thoughtfully each time the camera swung past – ideal audience reaction material, if you ask me…

Lewis Wolpert

Anyway, the gist of Wolpert’s talk as I understood it – which may not have been very well – was that humans are the only animals to have causal beliefs, the aforementioned concept of physical cause and effect. We evolved a ‘belief engine’ because it helped us understand enough about the physical world to make tools; religion arose because once we started working out why simple things happened we wanted to understand the causes of other, more complex events and believing in supernatural powers made us feel less anxious about not having all the answers.

We’ve still got this drive to understand why things happen, a psychological urge to explain even those events that have no simple, common sense answer. Think about the family of an air crash victim who, ten years on, still want to know exactly why the plane went down.

Our beliefs are all brain chemistry: when depressed you believe that you’re alone, that you’re unlovable – even thought these things are untrue. Tripping on LSD the meaning of life suddenly becomes clear (if you’re Timothy Leary). Mental patients subconsciously maintain delusions in the face of contradictory evidence.

All very interesting. The point of Cafe Scientifique is for the public to engage the speaker so an hour of audience participation followed Wolpert’s talk: some people asked interesting questions or voiced thoughtful opinions and some people, um, talked to hear the sound of their own voice.

It was a worthwhile hour and a half, anyway. The next event was in May, I think, though I’m not sure exactly when – keeping an eye on the Nature Network events page is perhaps the best course of action if you’re interested in going along.