Say the word ‘statistician‘ and most people might think of an intelligent but reclusive person, probably working in a darkened room and almost certainly wearing glasses. But a new study shows that a monkey in front of a monitor can make a reasonably good statistician too.
Tianming Yang and Michael Shadlen from the University of Washington found that rhesus macaques can perform simple statistical calculations, and even watched their neurons doing it. Psychologists often train animals to learn simple tasks, where the right choice earns them a reward and the wrong one leaves them empty-handed or punished. But real life, of course, is not like that.
Mostly, there are risks and probabilities in lieu of guarantees or right answers. Animals must weigh up the available information, often from multiple sources, and decide on the course of action most likely to work out in their favour.
Yang and Shadlen tested this decision-making ability in two rhesus macaques using a variation of the well-known weather prediction task used to test human volunteers. In the human version, people are shown a series of cards that represent various probabilities of good or bad weather. After some training, they are shown combinations and asked to predict the likely weather from these.
The monkeys had a slightly simpler task – they had to look at either a green or a red target. If they picked the right one (which changed from trial to trial), they were rewarded with a tasty drink. To help the monkeys choose, Yang and Shadlen showed them a series of shapes that represented the probability that the rewarding target was red or green.
Three years ago, Lawrence Summers, former president of Harvard University, claimed that genetic differences between the sexes led to a “different availability of aptitude at the high end”. His widely derided led to his dismissal, but is views are by no means uncommon. In the same year, Paul Irwing and Richard Lynn conducted a review of existing studies on sex differences in intelligence and concluded:
“Different proportions of men and women with high IQs… may go some way to explaining the greater numbers of men achieving distinctions of various kinds for which a high IQ is required, such as chess grandmasters, Fields medallists for mathematics, Nobel prize winners and the like.”
Irwing’s opinion aside, there clearly is a lack of women in the areas he mentioned. In chess for example, there has never been a single female world champion and just 1% of Grand Masters are women. And as long as that’s the case, there will always be people who claim that this disparity is caused by some form of inferiority on the part of the underrepresented sex. Thankfully, there will also always be others keen to find out if those who hold such views are full of it.
Among them is Merim Bilalic from Oxford University. Himself a keen chess player, Bilalic smelled a rat in Irwing’s contention that men dominate the higher echelons of chess because of their innate ability. In an elegant new study, he has shown that the performance gap between male and female chess players is caused by nothing more than simple statistics.
Far more men play chess than women and based on that simple fact, you could actually predict the differences we see in chess ability at the highest level. It’s a simple statistical fact that the best performers from a large group are probably going to be better than the best performers from a small one. Even if two groups have the same average skill and, importantly, the same range in skill, the most capable individuals will probably come from the larger group.