A great mind does not always make for a great bank balance, according to research that suggests the richest people are no cleverer than the rest of us.

Scientists in the United States have found that while average incomes tend to increase with IQ scores, intelligence has very little to do with absolute wealth.

A high IQ also offers no protection against falling into heavy debt or other kinds of financial mismanagement. The very brightest are more likely to have money problems than those who are slightly above average intelligence.

The findings, from a team at Ohio State University, could reflect the way in which many of the most impressive fortunes are not amassed through steady accumulation of high salaries, but by other means that are not influenced heavily by academic intelligence.

Most of the richest people in Britain, for example, are not salaried, but rather have amassed their fortunes as entrepreneurs or by inheritance.

The research, led by Jay Zagorsky, has not yet examined in detail why IQ seems to be linked to income but not to wealth, but early indications suggest that differences in saving may be part of the answer. “People don’t become rich just because they are smart,” Dr Zagorsky said. “Your IQ has really no relationship to your wealth. And being very smart does not protect you from getting into financial difficulty.”

In the study, published in the journal Intelligence, Dr Zagorsky examined detailed data from 7,403 Americans who had been interviewed repeatedly since 1979. IQ scores were compared with income and overall wealth, and participants were asked whether they had ever reached their limit on a credit card, been declared bankrupt or missed paying bills for financial reasons.

It found that IQ was strongly linked to income, with each extra point of IQ worth between $202 (£101) and $616 (£308) a year. The average annual income difference between a person with a normal IQ, of 100, and a person in the top 2 per cent, with an IQ of 130, was between $6,000 (£3,000) and $18,500 (£9,250).

Overall wealth, however, was not correlated strongly with IQ, and there were mixed results regarding financial problems. While people with low IQs were the most likely to have reached their limit on credit cards, those with very high IQs were more likely to have had financial difficulties than those with slightly above-average intelligence.

“In these measures of financial difficulties, it seems that those of slightly better-than-average intelligence are best off,” Dr Zagorsky said.

“Just because you’re smart doesn’t mean you don’t get into trouble. Among the smartest people, those with IQ scores above 125, even 6 per cent of them have maxed out their credit cards and 11 per cent occasionally miss payments.

“Financial success for most people means more than just income. You need to build up wealth to help buffer life’s storms and to prepare for retirement. You also shouldn’t have to worry about being close to or beyond your financial limits.”

He said that the tendency of university academics not to be rich reflected that wealth was poorly linked to IQ.

“Professors tend to be very smart people,” he said. “But if you look at university parking lots, you don’t see a lot of Rolls-Royces, Porsches or other very expensive cars.

“Those with low intelligence should not believe they are handicapped, and those with high intelligence should not believe they have an advantage.”

Schooled in wealth

Duke of Westminster inherited a property empire but left Harrow with one O level. Failed Sandhurst exam and went on to command the Territorial Army

Sir Richard Branson Virgin founder left school at 15. Now has a fortune of £3 billion

Sir Alan Sugar Amstrad entrepreneur left Brooke House School in East London aged 16 to set up his first company, selling car aerials from the back of a van

Sir Philip Green Retail tycoon left school without qualifications aged 15. Is now worth an estimated £3.6 billion

Prince of Wales attended Trinity College, Cambridge, with a relatively meagre two A levels in 1967

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