The suntan diversion

Scientific research has just revealed that battery eggs are as good as free range ones. Measurements published in Nature have shown that they only differ in their vitamin B12 content. Any difference in taste, we are assured, is without scientific basis and must therefore be purely imaginary. This is a perfect illustration of both 'The Lamp Post Lark' and 'The Suntan Diversion' - associated variants of the same basic fallacy.

Let us start with 'The Lamp Post Lark'. It is a particularly dark night. A number of people are clustered round a lamp post frantically searching for something on the pavement. "What are you looking for?" asks a passer-by. "My wallet", answers a rather desperate searcher. "Are you sure you lost it here?" asks the passer-by. "No", answers the searcher, "but this is the only part of the street that is lit up."

Our scientists proceed on precisely the same way. They have been taught to look at things that are measurable to the exclusion of those that are not. Hence, they pretend that the latter do not exist.

Anyone but a fool must realise that, if measurements have revealed that battery eggs are as good as free range ones, then these measurements must be wrong. In the same way, if you introduce a stick into your petrol tank and find that it is empty, and you then get into your car, turn on the ignition, and lo and behold it runs perfectly smoothly, you do not conclude that your car has learnt overnight to function without petrol.

Instead you will assume, quite rightly, that you didn't put the stick in far enough, or didn't look at it carefully. In other words, you are not going to accept the results obtained from a measurement if it is incompatible with all the knowledge you have built up on the subject. This is precisely the case with the conclusion drawn from the measurements reported in Nature. They are incompatible with the information built into the human tasting process.

Let us consider this a little more closely. It is reasonable to suppose that, to an animal living in its natural environment, things that taste good are good. The mechanism of taste can only be regarded functionally as a device to enable animals, including man, to select the correct constituents of their diet. Through the functioning of this mechanism, dung beetles, fiddler crabs and also primitive people know what to eat and not to eat. None of them requires nutritionists to advise them on this score. It follows that there must be a vast amount of information built into this mechanism - information which clearly reflects the experience of the species over many millions of years.

Why should we, the most sophisticated of creatures, have lost the ability to feed ourselves correctly? The answer, of course, is that this mechanism cannot work once our environment has been too radically modified, and no longer resembles that in which we have evolved. For instance, in the artificial conditions in which we live, we can only imperfectly distinguish between real food and its better imitations, and possess no means whatsoever for detecting the presence in our food of contaminants of which we have had no evolutionary experience, such at DDT, or radioisotopes. Our environment, in fact, has become counter-intuitive. That is why we need science to provide us with the information that we can no longer obtain by normal means.

It is my thesis that, even with the best possible science, we cannot adapt to a counter-intuitive environment, and, as it is, our science is far from being the best possible science.

'The Suntan Diversion' takes things a stage further. Its object is to divert attention from the important factors involved in a given situation, which are quite irrelevant to the situation at hand. We are deluded into accepting a particular thesis because we have been persuaded to judge it on the basis of totally false criteria.

The fact that cow's milk contains more protein than human milk is used to support the thesis that it must be better than a human mother's milk but it ignores the fact that human babies at birth require less protein than do calves for the simple reason that they don't grow so quickly. On the other hand, more polyunsaturated fats are required in human milk to build up nerve tissue because a child's brain grows at birth much more quickly than does a calf's.

To take another example, Lord Zuckerman tells us that the seas are in excellent shape, since "catches of fish have never been higher": thereby applying a totally false criterion for judging the health of a marine ecosystem. This can only be judged by its stability, which involves maintaining the requisite variety and number of trophic levels, and these will have the negative effect of reducing total production. Production is never higher, for instance, than before a population crash. And so it goes on.

It is by means of such expedients as 'The Lamp Post Lark' and 'The Suntan Diversion' that we are made to accept the false criteria applied by our experts to judge the functioning of the biosphere and to justify their increasingly counter-productive efforts to control it.