Animal intelligence 17 August 1981

Trevor Leggett was head of the Japanese Department of the BBC.

This is one of his broadcasts to Japan

ZUBARI for  17 August 1981

Animal intelligence

Some scientists say that animals are, more or less, little machines – they seem to be intelligent because their internal ‘programmes’ make efficient at hunting or nest-building and so on.  It seems that birds build nests in intelligent anticipation of the future children.  But this, the scientists say, is an illusion.  The animal simply follows out a fixed inner programme, like a computer.  The programme has been evolved under the stress of natural selection – the efficient programmes survived, the others die out.

But anyone who has observed animals for a long time becomes convinced that they have feelings, sometimes quite complicated ones, which have nothing to do with surviving.

My back balcony overlooks a big garden, beyond which is a large park.  There are many old trees in the garden and the line of gardens on each side of it.  In these trees there are squirrels.  In the morning, I often see them jumping from tree to tree.

In the houses next to the park, there are cats.  And sometimes I see, in the nearly morning, a cat exploring in the trees.  He tries to catch the squirrels, when he sees them.  Sometimes there is a short chase, which always ends with the squirrel dashing into the thin outer branches of the tree, where the cat, because of its weight, cannot follow.

One would think that would be the end of the matter.  But no. The squirrel in the thin branches evidently knows that the cat cannot follow him. He does not move away, though there are many other interlocking thin branches just by him.  He stays there, looking round at the cat.  Then he waves his big tail deliberately from side to side.  The cat goes nearly mad with frustration – it is excited by the waving tail, and keeps crouching as if it would spring.  But it cannot – it knows, as the squirrel knows, that the branch would give no hold to its claws.  The squirrel can hold on quite safely with its little hands.

Well, such behaviour cannot be explained on the ‘inner computer’ hypothesis.  The squirrel clearly is enjoying teasing the cat, though it can give it no advantage in any way in the ‘survival of the fittest’.

© Trevor Leggett