Old people don't have a sense of humor

Ok ok... they do have a sense of humor but... age related cognitive decline has led to many older adults not getting 'the joke'. In a study by Wingyun Mak and Brian Carpenter, Ph.D. , of Washington University they discovered that

Humor comprehension in older adults functions in a different fashion than humor comprehension in younger adults. The researchers studied older adults from a university subject pool as well as undergraduate students. The subjects participated in tests that indicated their ability to complete jokes accurately as well as tests that indicated their cognitive capabilities in areas of abstract reasoning, short - term memory, and cognitive flexibility. Overall, older adults demonstrated lower performance on both tests of cognitive ability as well as tests of humor comprehension than did younger adults.

Interested? Here's the rest of the press release and the citation:
Journal of the International Neuropsychological Society (2007), 13: 606-614