By Dick Taylor
Is it possible to measure something as complex as the brain?
Is David Beckham intelligent? Perhaps he is. Is he intelligent in the same way as Stephen Fry? Perhaps not.
The problem with intelligence has been to find ways of fairly assessing both types - and many others.
Try these two questions:
How do you define "fallacy"?
- If I say to you a random series of 9 numbers, for example: 7, 4, 8, 7, 3, 6, 6, 2, 5, can you repeat them back to me in reverse order?
These are typical of questions found in an IQ test and for some experts your performance on questions like these says an awful lot about how intelligent you are.
Can this be right? Can intelligence really be measured by tests like these? Well, it has been for more than 100 hundred years, ever since Alfred Binet and Theodore Simon started testing French school children in 1905.
But some experts, like Professor Howard Gardner from Harvard University, are now suggesting that it is time to move on.
"The IQ tests a lot of old knowledge, academic knowledge and skills, but nothing about whether you will actually do anything in the world," he observed.
The Horizon programme took seven people who are all experts in their own field and put them through a range of "intelligence" tests.
We had Quantum physicist Seth Lloyd; ex-Wall Street Trader Nathan Haselbauer, who runs the International High IQ society; musical prodigy Alex Prior; artist Stella Vine; RAF fighter pilot Garry Stratford; international chess grandmaster Susan Polgar and dramatist/critic Bonnie Greer.
The IQ-type tests produced predictable results. The IQ expert and Quantum physicist came out on top.
But what about "creativity"? It is not really tested by an IQ test.
Robert Sternberg, from Tufts University, Boston, maintains it's essential: "Creativity was a tool for the high flyers - the Einsteins, the Darwins, the Newtons. But now the world has changed so much that creativity is now a vital part of intelligence for everyone"
We assessed creativity by using a test developed in the 60s: "Name as many uses as you can for a sock in 10 minutes."
The results were interesting. One of the high scorers on the IQ performed poorly; the other, extremely well. The creatives in our group also did very well, as you would expect.
The intriguing thing about this "alternative uses" test is that it is not just the number of alternative uses that count, it is the originality of them and the extravagance of the description that also count.
So a sock that could be used as a "bikini bottom, tied on with string - provided you were waxed - and that you were daring", suggested by Bonnie Greer, gets a good score.
The seven volunteers where subjected to a variety of tests
So the test is also looking for "playfulness". Is that intelligence?
We also tested "emotional intelligence". The results were very surprising.
Professor Jack Mayer, from the University of New Hampshire, and others maintain that our ability to recognise what other people are going through, why they change from one emotion to another and also to understand what we ourselves are feeling, are aspects of intelligence. If we are good at it we will prosper.
It is the oddness of the tests that put some people off. When shown a picture of pebbles on a beach how much happiness do you feel on a scale of one-to-five?
We thought we had picked some highly emotional intelligent people amongst our seven guinea pigs. According to the tests, we were wrong.
Is there a view of intelligence that would put Beckham and Fry on an equal footing? Howard Gardner's controversial theory of multiple intelligences fits the bill.
According to Gardner we all have at least 8 types of intelligence - one of them being "bodily intelligence".
Unfortunately, David Beckham was unavailable somewhere between Madrid and Hollywood. But in our test, the artist beat the fighter pilot!
Horizon: Battle of the Brains is on Tuesday 17 April at 2100 BST on BBC Two