The late Professor Hans Eysenck once told me about an experiment in which a population of rats was divided into ‘bright’ and ‘dull’ on some criterion for rat intelligence. The rat offspring were then switched to different parents, in such a way that the bright rats were given the offspring of the dull rats to bring up, and vice versa. It was found that the bright rats brought up the dull rat babies successfully, while the dull rats killed the bright rat babies which they were given.
As Richard Dawkins points out in The Selfish Gene, natural selection encourages forms of behaviour which secure favourable conditions for the descendants of the individual in subsequent generations. So it looks as if it may be advantageous for the survival of a rat if the number of rats in the population it has to compete with, which are descended from parents cleverer than its own, is minimised.
The experiment suggests it may have become programmed into the genetic constitution of rats that they should kill, if possible, young rats which are cleverer than themselves. On the other hand, it appears rats have no programming to kill young rats which are less clever than themselves, presumably because their presence in future populations would pose no serious threat to their own offspring.
If natural selection has favoured such behaviour in rats to the point of modifying their genotype, we may speculate that it is even more likely to be present in the human constitution, since the range of opportunities present in human society, and the ways in which advantage may be taken of them, are even more varied, and offer greater potential advantages to those able to make use of them, than the variety of circumstances which may be made use of by rats of differing abilities.
Someone who becomes aware of this experiment may well be shocked by the result, and protest that it could not possibly be applied to humans. Professor Eysenck himself seemed to have resistance to the implication. He told me that anti-high-IQ behaviour would only prove adaptive for people in more developed societies, and thus could not have had time to modify the human genotype. His argument was that only in developed societies, with extensive business and finance activities, would having a higher IQ give the owner a sufficient advantage, to motivate other people to be hostile to him, or even kill him. This argument did not, however, make much sense to me, given that rats can scarcely be said to have ‘developed societies’ in this sense.
If there is a tendency in humans corresponding to the desire of rats to kill young rats cleverer than their own offspring, it would certainly help to explain the way the education system has developed as society has become progressively democratised. In spite of occasional nods to the supposed special needs of the ‘gifted’, the system is clearly geared (and increasingly so) to promoting the interests of the low-IQ population, and to making life well-nigh impossible for those of exceptional ability.
There is evidently a resistance to considering the possibility that the average human being may have hostile (potentially to the point of murderous) attitudes, whether conscious or not, to individuals of exceptional ability. Professor Eysenck told me that the results of this experiment became unavailable soon after it had been carried out – though he didn’t explain why – so it may be that they have never been published.