Chess: Catching up the fruit fly

PSYCHOLOGISTS have taken such an interest in chess that the game has been described in a book entitled Complex Information Processing as 'the drosophila of psychology'. Research on chess does not quite match that on the fruit fly, but recent additions mean it is catching up.

'The general intelligence and spatial abilities of gifted young Belgian chess players' (British Journal of Psychology, 1992) not only contains in its title one of the most memorable oxymorons of our time, but even suggests that 'a high level of general intelligence and spatial ability are necessary to achieve a high standard of play in chess'.

N J Cooke, R S Atlas, D M Lane and R C Berger, in 'Role of high-level knowledge in memory for chess positions' (American Journal of Psychology, 1993) claim their experiments show that an abstract type of high-level perceptual knowledge underlies skill at chess. Neither these, nor any previous research, however, has anywhere near as great a potential impact as 'Testosterone and Chess Competition', by A Mazur, A Booth and J M Dabbs (Social Psychology Quarterly, 1992).

'The hormone testosterone (T) has a central role in recent theories about allocation of status ranks during face-to-face competition,' they explain. Concentration of testosterone has been shown, in a variety of animal and human studies, to relate to aggression, assertiveness and dominance.

Roughly speaking, the theory predicts that in sporting contests the higher your testosterone level, the more competitive you will be, and the more competitive you are, the higher your T-level will rise.

'With non-human subjects, the usual method of studying the effect of T on behaviour is to manipulate the hormone level, either by injection or (in males) by removal of the testes, the main T-producing organs. For human subjects this method is neither practical nor safe.' In the present study, 16 male tournament players had their T-levels measured by saliva samples taken the day before, just before, and just after each round.

The results confirmed their predictions: T-levels of winners rose, and losers' declined over the course of a game. Furthermore, these effects were most marked when the competition was most intense, in the crucial rounds, or in games between evenly matched opponents. Still more interesting was the fact that in the day before the game, the T-level of the eventual winners rose more than the T-level of the losers.

So, measuring changes in a player's testosterone level over the day preceding an important contest could provide a predictor of the result.