“The development of full artificial intelligence could spell the end of the human race.” —Stephen Hawking, Dec. 2 Does artificial intelligence threaten our species, as the cosmologist Stephen Hawking recently suggested? Is the development of AI like “summoning the demon,” as tech pioneer Elon Musk told an audience at MIT in October? Will smart machines supersede or even annihilate humankind? As a cognitive scientist and founder of a new startup that focuses on “machine learning,” I think about these questions nearly every day. But let’s not panic. “Superintelligent” machines won’t be arriving soon. Computers today are good at narrow tasks...