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

128 HOW THE MIND WORKSmatic." Their boast is a twentieth-century echo of Hume's remark thatfrom a body similar to bread in color and consistency we expect a similardegree of nourishment. But the assumption breaks down in any domainin which a person actually knows something. The onion-loving gorillawas intended only as an example, of course, but it is interesting to seehow even this simple example underestimates us. Knowing a bit of zoologyand not much about gorillas, I would definitely not raise my estimateof the probability that gorillas like onions. Animals can be cross-classified.They may be grouped by genealogy and resemblance into a taxon, such asthe great apes, but they also may be grouped into "guilds" that specializein certain ways of getting food, such as omnivores, herbivores, and carnivores.Knowing this principle leads me to reason as follows. Chimpanzeesare omnivores, and it is not surprising that they eat onions; after all, weare omnivores, and we eat them. But gorillas are herbivores, who spendtheir days munching wild celery, thistles, and other plants. Herbivores areoften finicky about which species they feed on, because their digestivesystems are optimized to detoxify the poisons in some kinds of plants andnot others (the extreme example being koalas, who specialize in eatingeucalyptus leaves). So it would not surprise me if gorillas avoided thepungent onion, regardless of what chimpanzees do. Depending on whichsystem of explanation I call to mind, chimpanzees and' gorillas are eitherhighly similar category-mates or as different as people and cows.In associationism and its implementation in connectoplasm, the wayan object is represented (namely, as a set of properties) automaticallycommits the system to generalizing in a certain way (unless it is trainedout of the generalization with specially provided contrary examples). Thealternative I am pushing is that humans can mentally symbolize kinds ofobjects, and those symbols can be referred to in a number of rule systemswe carry around in our heads. (In artificial intelligence, this techniqueis called explanation-based generalization, and connectionistdesigns are an example of the technique called similarity-based generalization.)Our rule systems couch knowledge in compositional, quantified,recursive propositions, and collections of these propositionsinterlock to form modules or intuitive theories about particular domainsof experience, such as kinship, intuitive science, intuitive psychology,number, language, and law. Chapter 5 explores some of those domains.What good are crisp categories and systems of rules? In the socialworld they can adjudicate between haggling parties each pointing at thefuzzy boundary of a category, one saying something is inside and the