The boy is struggling with his homework. "If there are 4,700 apples in the orchard, and 16 pickers, the fastest of whom picks 50% more than the slowest..." In despair, he turns to his brother for help, only to get a withering put-down: "Come on, stupid - you don't have to be a rocket scientist to work it out."

This phrase and its alternative - "you don't have to be brain surgeon" - are so widely used that we have come to accept the two professions as the cleverest on the planet. But might one be cleverer than the other? Researchers tried using a test devised at Imperial College, London to find out.

The Great British Intelligence Test focuses on six different areas such as reasoning, memory and concentration. It was taken by 329 aerospace engineers and 72 neurosurgeons. Their scores were compared with each other's - and with those of 18,000 members of the public.

The results were a revelation. The engineers proved better than the surgeons at concentration and mental exercises such as rotating objects in their heads. The surgeons scored much higher in word puzzles.

But the strangest discovery was that the public did just as well as the rocket scientists in every area. And though the neuroscientists were quicker at solving problems than people in general, they were less good at memorising things.

"It shows is that everyone has a range of skills," said one of the study's authors, Aswin Chari. "It is very difficult to be better in everything across the board."

To many, Wernher von Braun was the epitome of the brilliant scientist. Born in Germany, he helped develop the V-2 rocketsAround 5,000 people were killed in attacks on the UK, France and Belgium. in World War Two. He was captured by US forces, and went on to mastermind the rockets used in the ApolloA US space programme which ran from 1961 to 1972 and took 12 astronauts to the moon and the ancient Greek god of the sun, poetry, and archery. space programme.

He was also an excellent pianist who could play complicated pieces from memory, and even thought of becoming a composer.   

Writers and film-makers have long delighted in mad scientists. Mary ShelleyShe wrote Frankenstein as part of a contest to write a ghost story. Lord Byron and her husband Percy Bysshe Shelley competed against her. paved the way with her 1818 novel FrankensteinA novel about a scientist who builds a monster out of different human body parts.. Jules Verne gave the world Captain NemoThe inventor of an enormous submarine called the Nautilus. in 20,000 Leagues Under The Sea (1870). In 1933, Norman Hunter dreamt up Professor Branestawm, whose inventions included the unspillable tea cup.

Defining intelligence, though, is extremely difficult. AristotleA student of Plato, tutor to Alexander the Great and the father of political philosophy. promoted the idea of "reason", which meant the ability to control our instincts. This held sway for some 2,000 years.

In the 19^th Century, George RomanesA Canadian-English biologist who was one of the founders of modern psychology. He was heavily influenced by Charles Darwin's theory of evolution. came up with the term "intelligence", meaning a person's ability to adapt to and succeed in their environment. In World War One, the US army developed the IQA means of measuring human intelligence. A person's IQ is usually ascertained by making them sit a standardised test. Some have criticised these tests as a means of evaluating intelligence, claiming that they ignore much of what it means to be intelligent. test to measure various mental skills and work out recruits' aptitude for particular jobs.  

In the 1980s, psychologist Howard Gardner suggested that there are many different types of intelligence, from logical to emotional. But others argue that intelligence cannot be divided up in this way.

Some say, yes: there are many different kinds of intelligence, and we all possess at least one kind. Taking a free kick in football, for instance, requires minute calculations about how hard to kick the ball and where to place it, even if the player is not aware that he or she is making them.

Others argue that intelligence is about solving problems, and the ability to do that varies widely. Learning a language or designing a car is far more mentally demanding than kicking a football. If we were all equally intelligent, everyone would be top of the class.