Are men smarter than women?

Intelligence is a subject close to every ambitious parent's heart. IQ testing tends to stir passionate responses among just about everyone, not least because studies regularly show differences between the sexes.

Are boys really more intelligent than girls? Most laypeople assume they are. They consistently rate their male relatives as smarter than their female relatives, whether they themselves are male or female. Children think they are brighter than their parents, but especially their mothers. They consider themselves far more intelligent then their grandparents, but especially their grandmothers. Parents of both sexes agree that their children are brighter than they are, but especially their sons. These findings are cross-culturally robust, having been demonstrated in Hong Kong and Japan as well as South Africa, Belgium and the United States.

However, though a considerable social influence in itself, how much credibility can be given to lay opinion? After all, virtually everyone thinks they are more intelligent than the average while, by definition, half of them must fall below the average mark. Men consistently overestimate their own overall IQ while women consistently do the contrary.

Nevertheless, while hotly contested for reasons I go into below, from Scotland to China, males consistently come out slightly above females in all the most widely used IQ tests. The obvious question is: Why? Experts have come up with a number of explanations.

One obvious explanation is that these tests simply reflect reality. Men may simply benefit from a superior genetic endowment with respect to intelligence. Indeed, amid a public furore on the subject a number of years back, 50 of the world's top experts were moved to write to the Wall Street Journal to register their belief that intelligence was mostly a matter of genetics.

But what, exactly, is measured in IQ tests? Laypeople generally consider intelligence in far broader terms than conventional tests allow. This is one of the reasons why the theory of multiple intelligences, advanced by Harvard psychologist Howard Gardner, holds considerable appeal. Of his seven intelligences, only two are valued at school - verbal, or linguistic; and logical, or mathematical. Three are valued in the arts - spatial intelligence, musical intelligence and body-kinetic intelligence. And a further two relate to emotional intelligence: interpersonal intelligence (understanding other people) and intrapersonal intelligence (understanding oneself).

Research into these concepts of intelligence by Adrian Furnham, a professor at University College London, shows that most people wildly overestimate their own interpersonal and intrapersonal intelligence. He discovered that people tend to 'weight' these intelligences differently, giving more importance in overall intelligence to logical, then spatial, then verbal, intelligence. A pattern, in other words, that corresponds exactly to male strengths.