The social function of intellect

Henry Ford, it is said, commissioned a survey of the car scrap yards of America to find out if there were parts of the Model T Ford which never failed. I lis inspectors came back with reports of almost every kind of breakdown : axles, brakes, pistons all were liable to go wrong. But they drew attention to one notable exception, the kingpins of the scrapped cars invariably had years of life left in them. With ruthless logic Ford concluded that the kingpins on the Model T were too good for their job and ordered that in future they should be made to an inferior specification. Nature is surely at least as careful an economist as Henry Ford. It is not her habit to tolerate needless extravagance in the animals on her production lines: superfluous capacity is trimmed back, new capacity added only as and when it is needed. We do not expect therefore to .find that animals possess abilities which far exceed the calls that natural living makes on them. If someone were to argue as I shall suggest they might argue that some primate species (and mankind in particular) are much cleverer than they need be, we know that they are most likely to be wrong. But it is not clear why they would be wrong. This paper explores a possible answer. It is an answer which has meant for me a re-thinking of the function of intellect. A re-thinking, or merely a first-thinking? I had not previously given much thought to the biological function of intellect, and my impression is that few others have done either. I n the literature on animal intelligence there has been surprisingly little discussion of how intelligence contributes to biological fitness. Comparative psychologists have established that animals of one species perform better, for instance, on the Hebb-Williams maze than those of another, or that they are quicker to pick up learning sets or more successful on an ` insight ' problem; there have been attempts to relate performance on particular kinds of tests to particular underlying cognitive skills; there has (recently) been debate on how the same skill is to be assessed with fairness ' in animals of different species; but there has seldom been consideration given