Boris Johnson has admitted that IQ was not the "only measure of ability" after he failed to answer a single intelligence test question correctly during a live radio interview.
In a much criticised speech, the Mayor of London said that discussion of equality had to take into account the IQs of people. He said that 16% of "our species" had an IQ of less than 85 and 2% had more than 130.
"The harder you shake the pack, the easier it will be for some cornflakes to get to the top," he said.
Johnson, who was famously educated at Eton, was asked to answer a series of standard IQ test questions by presenter Nick Ferrari on his regular LBC Radio slot "Ask Boris".
After incorrectly guessing the first two questions, Johnson refused to answer the third. He said he was waiting to be asked some "more sensible questions".
The first IQ test question Ferrari asked was: "A man builds a house with four sides, each side having a southern exposure. A big bear comes along. What colour is the bear?"
As each wall has a southern exposure, the house must be located on the North Pole, meaning the bear is a white polar bear. But Johnson answered: "The bear is probably brown. I haven't got a clue what the colour of the bear is, nor is it relevant to this discussion."
The next question was: If you take two apples from three apples, how many apples do you have? Johnson replied: "You've got loads of apples, mate. You've got one apple left." The correct answer is two apples.
When Johnson refused to answer a third question, Ferrari said: "You didn't get any of the IQ questions right so who are you to lecture about IQ, Mr Mayor?"
Johnson wriggled and said that his controversial remarks at the annual Margaret Thatcher lecture may have been "misinterpreted".
He said: "What I was saying actually is there is too much inequality and my speech was actually a warning, as correctly reported by many newspapers, actually a warning against letting this thing go unchecked because if you look at what's happened in the last 20, 30 years there's been a widening in income between the rich and the poor, there's no question about that."
Johnson's comments that people with low IQs tended to struggle in life was condemned by several members of the coalition. Deputy prime minister Nick Clegg described his speech as "careless elitism" while fellow Eton alumni chancellor George Osborne admitted he would not have "put it like that".
In the Ferrari interview, Johnson also struggled to answer how much a one-way tube ticket from Angel in north London to London Bridge would cost.
During more than a minute of "dead air", Johnson could be heard sorting through his notes before incorrectly answering £6.70, a fare that would get a traveller all the way out to London's far suburbs.
Johnson eventually correctly gave the fare as £4.50.