The New York Times has a ponderous piece on when it might be best to "come clean" with children about Santa, if, ahem, you know what I mean. Here is but one sentence from professor of psychology:
The change in children's conceptualization of Santa is driven in part by cognitive development.
I love it when they talk dirty like that.
Some people, it must be noted, test their belief in Santa far longer than most of us did:
Officers followed the woman inside the arena and found she had a bottle of vodka hidden under her shirt. She and two others with her were also arrested on charges of public intoxication and possession of alcohol by a minor.
She was, of course, testing the theory that Santa's beard has some kind of magical property that helps him do all the incredible things he does, the absence of which, like Sampson's hair, will cause a fatal weakness. For the benefit of littlejohn, I should point out that this is not in all the literature.
On the other hand, she may have been testing the theory that vodka at a basketball game doesn't count.