Hawks and Doves
- Evolution and Theory of Games by John Maynard Smith
Cambridge, 224 pp, £18.00, October 1982, ISBN 0 521 24673 3
One of the many curious discoveries made, earlier this century, by ethologists such as Konrad Lorenz and Niko Tinbergen was that fighting in animals is restrained and, as they called it, ‘ritualised’. Animal contests, over such valuable resources as food, territory or mates, almost resemble tournaments, which pass through a regular series of harmless stages, before one animal emerges as the winner, and the other retreats unharmed as the loser. Take the cichlid fish Cichlasoma biocellatum, whose contests are described by Lorenz in his book On Aggression. A fight between two males passes through three main stages, at any of which one of the contestants may back out. They start with broadside displays, move on to tail beating, and then to harmless mouth fighting, in which the pair grip and pull each other by the mouth. The rules of the contest are, according to Lorenz, strictly obeyed. Each fish only moves on to the next stage when the other is ready. More strikingly still, if one of the fish finds itself in possession of a temporary but irregular advantage, it will not unfairly press it home. In Lorenz’s own words, ‘one of them may be inclined to go on to mouth-pulling a few seconds before the other one. He now turns from his broadside position and thrusts with open jaws at his rival who, however, continues his broadsides threatening, so that his unprotected flank is presented to the teeth of his enemy. But the aggressor never takes advantage of this; he always stops his thrust before his teeth have touched the skin of his adversary.’ Behaviour does not come much more gentlemanly than that.
Ritualised animal contests were not known before the 20th century. If Darwin had known of it, we can be quite sure that, with his interest in animal analogies of human morality, he would have greedily transcribed it into The Descent of Man. But the several sections of that work which are concerned with the ‘law of battle’, while containing an impressive list of carnage, assembled from a variety of anecdotal sources, are unrelieved by even the smallest hint of restraint on the animal battlefield.
In fact, it is still a matter of controversy whether, in particular cases, fighting is restrained or unrestrained. Lorenz, having discovered restrained fighting, has probably exaggerated its importance. But it is only its frequency that is controversial, not its existence: restrained fighting, for some species at least, is a fact of nature. This being so, it remains to ask why.
For Lorenz, there was no theoretical puzzle. It was just another illustration of the general principle that animals behave for ‘the good of the species’. If the members of a species do not hurt each other, then the species as a whole is better-off. But even as Lorenz was writing On Aggression, at the beginning of the Sixties, his ‘good of the species’ thinking was going out of date. Good of the species was to be replaced by good of the individual. That revolution has now penetrated into almost all departments of biology, and Lorenz himself, in his home in Altenberg, is one of the few to remain innocent of the change that has taken place.