Steven Pinker -- How the Mind Works - Hampshire High Italian ...

Revenge of the Nerds 179completely correct network by learning the other ten connections; if it hasa thousand occasions to learn, success is fairly likely. The successful animalwill reproduce earlier, hence more often. And among its descendants,there are advantages to mutations that make more and more of the connectionsinnately correct, because with more good connections to beginwith, it takes less time to learn the rest, and the chances of going throughlife without having learned them get smaller. In Hinton and Nowlan'ssimulations, the networks thus evolved more and more innate connections.The connections never became completely innate, however. Asmore and more of the connections were fixed, the selection pressure to fixthe remaining ones tapered off, because with only a few connections tolearn, every organism was guaranteed to learn them quickly. Learningleads to the evolution of innateness, but not complete innateness.Hinton and Nowlan submitted the results of their computer simulationsto a journal and were told that they had been scooped by a hundredyears. The psychologist James Mark Baldwin had proposed that learningcould guide evolution in precisely this way, creating an illusion of Lamarckianevolution without there really being Lamarckian evolution. But noone had shown that the idea, known as the Baldwin effect, would reallywork. Hinton and Nowlan showed why it can. The ability to learn altersthe evolutionary problem from looking for a needle in a haystack to lookingfor the needle with someone telling you when you are getting close.The Baldwin effect probably played a large role in the evolution ofbrains. Contrary to standard social science assumptions, learning is notsome pinnacle of evolution attained only recently by humans. All but thesimplest animals learn. That is why mentally uncomplicated creatureslike fruit flies and sea slugs have been convenient subjects for neuroscientistssearching for the neural incarnation of learning. If the ability tolearn was in place in an early ancestor of the multicellular animals, itcould have guided the evolution of nervous systems toward their specializedcircuits even when the circuits are so intricate that natural selectioncould not have found them on its own.INSTINCT AND INTELLIGENCEComplex neural circuitry has evolved in many animals, but the commonimage of animals climbing up some intelligence ladder is wrong. The