Old age affects your ability to get a joke, but it doesn't destroy your sense of humour, new research has found.

Canadian scientists tested two groups of volunteers, one with the average age of 73, the others around 28 to see how much they laughed at gags.

In one test, they were asked to spot which of a series of lines were meant to be funny and which weren't, and both groups scored equally well.

But when asked to identify the punchline of a gag from a multiple-choice selection, the younger group performed much better. Older people also found it more difficult to spot the humorous cartoons in a series of sketches.

The results, discovered by the Baycrest centre for geriatric care in Toronto, are published in the September issue of the Journal of the International Neuropsychological Society.