Children who are good at writing but poor at maths are a product of self-fulfilling "educational prophecies", according to a British academic.
Philip Adey, professor emeritus at King's College London, has spent much of his career conducting research into different theories of intelligence and argues that intelligence - or the ability to learn - is not fixed at birth.
For many years, he has asked teachers what they mean when they refer to a child's "intelligence" or "ability". And what about descriptions such as "she is very able" or "his ability is limited"?
Most teachers told him that they were referring to an ability to make connections between different ideas, apply new principles to a variety of contexts and see patterns in data - answers that are consistent with psychologists' traditional definitions, and with the version of intelligence measured by IQ tests.
But Adey says believing that a child's fundamental ability cannot be altered becomes a self-fulfilling prophecy. If a teacher - and therefore the pupils themselves - believes that intelligence is fixed, pupils' intelligence will become fixed.
"What is implied in the common conception of ability is that it is somehow an inborn characteristic of an individual," Adey says.
"The weakness of this position becomes clear if you take it to its limit: if general ability is really immune to influence, what are we doing in education?"
Indeed, taken to its natural extreme, this theory leads to a brave new world in which children are placed into ability groups from which they can never escape. Or, Adey suggests, the 11-plus exam.
"If we assume that the bottom set cannot cope with difficult ideas, and keep everything simple for them ... we are robbing them of the opportunity to grow intellectually," he says.
"Some develop what is essentially a fixed view of their own ability: believing, for example, that there ... is little point in working harder."
He goes on to examine the possibility that there are different forms of intelligences. Previous researchers have suggested various types, including logical-mathematical (such as Albert Einstein), verbal (such as William Shakespeare) and intrapersonal (such as Sigmund Freud). Other forms, such as emotional intelligence, have entered common discourse.
Adey says it is not difficult to understand why teachers would want to believe in multiple intelligences. "It allowed teachers, who on the whole are kind, liberal-minded people, to believe that everyone could be good at something," he says.
But there is little evidence to back up this theory. If one part of the brain is damaged, affecting its particular function, other parts of the brain often develop capability in the missing function.
So, Adey says, efforts to back up the multiple-intelligence theory with links to specific brain strengths fail.
Other people have cited the existence of savants as an argument for multiple intelligences. These are individuals, often autistic, who possess remarkable powers of memory, calculation, music or artistry but have learning difficulties elsewhere.
However, only about 100 such savants have ever been reported, and no more than half of those are alive today.
In fact, Adey argues, evidence suggests that there is always a correlation between different abilities. If individuals are strong in one particular area, it is likely that they will be strong in all areas.
Of course, there are cases where people develop particular skills to a remarkable degree of competence, eclipsing all others.
For example, a child who displays musical talent may be encouraged to put in hours of music practice at the expense of other skills. Likewise, a young footballer may neglect schoolwork in order to spend time on the pitch.
But their subsequent achievements will reflect effort and practice, rather than innate ability.
"Over the population as a whole, abilities in different areas are correlated," Adey says.
"The feeling one may have of being, say, good at writing but useless at maths, may be attributed to the self-fulfilling prophecy of expectations of pupils and teachers."
Adey, P., "From fixed IQ to multiple intelligences", in Adey, P. and Dillon, J., Bad Education: Debunking myths in education (McGraw Hill, 2012). bit.lyUCpSSv
Philip Adey, emeritus professor of science, cognition and education, King's College London.
HOW TO GROW INTELLIGENCE
Pupils' fundamental intelligence can change significantly with good teaching, a professor of cognition and education states.
Philip Adey (pictured right), of King's College London, says that, rather than being a "deterministic brake on what our students can achieve", intelligence responds significantly to external factors, such as upbringing, teaching and nutrition. This, he says, offers "a great opportunity to raise achievement across the board, with quite limited, but well-targeted intervention".
In particular, he discusses the impact of lessons that teach pupils to think more effectively. In one study, primary pupils were given an hour- long thinking-skills lesson each week for a year and a half. They made significant academic gains, compared with a control group of classmates. These gains continued to be evident even once the pupils had reached secondary school.
In another experiment, pupils whose science teachers emphasised thinking skills during Years 7 and 8 scored roughly one grade higher than their peers in GCSE science exams.
But this effect stretched more broadly: the pupils also outperformed their classmates in English and maths exams. This therefore confirms Adey's belief in an underlying general intelligence, rather than multiple, specific intelligences.
"Information can always be obtained from books and the web, but how to process that information, including critically evaluating it, making connections between different concepts and relating it to a particular issue at hand, depends on intelligence," he says. "The main function of the education process from nursery school ... should be to develop students' general intelligence."