The big idea: Should we worry about artificial intelligence?

Could AI turn on us, or is natural stupidity a greater threat to humanity?

Ever since Garry Kasparov lost his second chess match against IBM's Deep Blue in 1997, the writing has been on the wall for humanity. Or so some like to think. Advances in artificial intelligence will lead - by some estimates, in only a few decades - to the development of superintelligent, sentient machines. Movies from The Terminator to The Matrix have portrayed this prospect as rather undesirable. But is this anything more than yet another sci-fi Project Fear"?

Some confusion is caused by two very different uses of the phrase artificial intelligence. The first sense is, essentially, a marketing one: anything computer software does that seems clever or usefully responsive - like Siri - is said to use AI". The second sense, from which the first borrows its glamour, points to a future that does not yet exist, of machines with superhuman intellects. That is sometimes called AGI, for artificial general intelligence.