I understand that, at one stage, British authorities were concerned at the poor quality of tourists entering their country. An intelligence test had to be devised in order to sort out the problem and five committees formed to come up with a proposal.
The proposal was a simple test......to tie your own shoelaces. If you could tie them, you would be let in.
To see if the test was worthy it was agreed that the next plane landing at Heathrow would be targeted. It was a Qantas plane full of Aussies...all wearing thongs  (flip flops, rubber footwear etc).......the test was abandoned.