IS GEORGE W. BUSH stupid? It's a question that occupied a good many minds of all political persuasions during his turbulent eight-year presidency. The strict answer is no. Bush's IQ score is estimated to be above 120, which suggests an intelligence in the top 10 per cent of the population. But this, surely, does not tell the whole story. Even those sympathetic to the former president have acknowledged that as a thinker and decision-maker he is not all there. Even his loyal speechwriter David Frum called him glib, incurious and "as a result ill-informed". The political pundit and former Republican congressman Joe Scarborough accused him of lacking intellectual depth, claiming that compared with other US presidents whose intellect had been questioned, Bush junior was "in a league by himself". Bush himself has described his thinking style as "not very analytical".
How can someone with a high IQ have these kinds of intellectual deficiencies? Put another way, how can a "smart" person act foolishly? Keith Stanovich, professor of human development and applied psychology at the University of Toronto, Canada, has grappled with this apparent incongruity for 15 years. He says it applies to more people than you might think. To Stanovich, however, there is nothing incongruous about it. IQ tests are very good at measuring certain mental faculties, he says, including logic, abstract reasoning, learning ability and working-memory capacity - how much information you can hold in mind.
But the tests fall down when it comes to measuring those abilities crucial to making good judgements in real-life situations. That's because they are unable to assess things such as a person's ability to critically weigh up information, or whether an individual can override the intuitive cognitive biases that can lead us astray.
This is the kind of rational thinking we are compelled to do every day, whether deciding which foods to eat, where to invest money, or how to deal with a difficult client at work. We need to be good at rational thinking to navigate our way around an increasingly complex world. And yet, says Stanovich, IQ tests - still the predominant measure of people's cognitive abilities - do not effectively tap into it. "IQ tests measure an important domain of cognitive functioning and they are moderately good at predicting academic and work success. But they are incomplete. They fall short of the full panoply of skills that would come under the rubric of 'good thinking'."
IQ isn't everything
"A high IQ is like height in a basketball player," says David Perkins, who studies thinking and reasoning skills at Harvard Graduate School of Education in Cambridge, Massachusetts. "It is very important, all other things being equal. But all other things aren't equal. There's a lot more to being a good basketball player than being tall, and there's a lot more to being a good thinker than having a high IQ."
IQ tests and their proxies, which are designed to measure a factor known as general intelligence, are used by many businesses and colleges to help select the "best" candidates, and also play a role in schools and universities, in the form of SAT tests in the US and CATs in the UK. "IQ tests determine, to an important degree, the academic and professional careers of millions of people in the US," Stanovich says in his book, What Intelligence Tests Miss (Yale University Press, 2008). He challenges the "lavish attention" society bestows on such tests, which he claims measure only a limited part of cognitive functioning. "IQ tests are overvalued, and I think most psychologists would agree with that," says Jonathan Evans, a cognitive psychologist at the University of Plymouth, UK.
Indeed, IQ scores have long been criticised as poor indicators of an individual's all-round intelligence, as well as for their inability to predict how good a person will be in a particular profession. The palaeontologist Stephen Jay Gould claimed in The Mismeasure of Man in 1981 that general intelligence was simply a mathematical artefact and that its use was unscientific and culturally and socially discriminatory. Howard Gardner at the Harvard Graduate School of Education has been arguing - controversially - for more than 25 years that cognitive capacity is best understood in terms of multiple intelligences, covering mathematical, verbal, visual-spatial, physiological, naturalistic, self-reflective, social and musical aptitudes.
Yet unlike many critics of IQ testing, Stanovich and other researchers into rational thinking are not trying to redefine intelligence, which they are happy to characterise as those mental abilities that can be measured by IQ tests. Rather, they are trying to focus attention on cognitive faculties that go beyond intelligence - what they describe as the essential tools of rational thinking. These, they claim, are just as important as intelligence to judgement and decision-making. "IQ is only part of what it means to be smart," says Evans.
