The experiment, run on 29 baboons by Joel Fagot of the University of Provence and Roger Thompson of Marshall College, found that the monkeys could ignore the fact that some symbols were more familiar from previous sessions and stick with the task of selecting those that came in pairs, and that they still partly recalled the skill after a year.
Down goes another claim of human uniqueness. It had been argued that only human beings could reason by analogy because only human beings use grammatical language. Indeed, language is suffused with analogy, comprehensively infiltrated with metaphor—analogy's sibling—to the point that we no longer notice it. (In the previous sentence, for instance, consider that "suffused," "infiltrated," etc. are all metaphors.)
In his new book "The Better Angels of Our Nature" (reviewed on page C7), Steven Pinker points out that, for centuries, perpetrators of genocides have described their victims in biological terms laced with disgust: as rats, snakes, maggots, lice or diseases. This presumably helps them justify to their followers the inhuman acts they commit. Metaphors possess considerable power to move us.
Certainly, analogies can generate insights. I am fond of using one from the works of Shakespeare to explain how a mouse and a human can have mostly the same genes and yet be very different. In his plays, the bard used a vocabulary of about 20,000 words (not counting inflections like plurals), just as a mammal has about 20,000 genes. The difference between two Shakespeare plays lies not so much in the vocabulary as in the order of the words. Indeed, the six most frequent words in "Othello," "Lear" and "Hamlet" are the same: the, and, to, of, I and you. So it is with genes: the difference between a mouse and a man is in the order and pattern of expression of the genes, not in having different genes.