I've long entertained a dubious regard for the practice of lying to children about the existence of Santa Claus. Parents might claim that it serves to make children's lives more magical and exciting, but as a general rule, children are adequately equipped to create fantasies of their own without their parents' intervention. The two reasons I suspect rest at the bottom line are adherence to tradition, and finding it cute to see one's children believing ridiculous things.
Personally, I considered this to be a rather indecent way to treat one's own children, and have sometimes wondered whether a large proportion of conspiracy theorists owe their origins to the realization that practically all the adults in the country really are conspiring to deceive children for no tangible benefit. However, since I began frequenting this site, I've been exposed to the alternate viewpoint that this realization may be good for developing rationalists, because it provides children with the experience of discovering that they hold beliefs which are wrong and absurd, and that they must reject them.
So, how did the Santa deception affect you personally? How do you think your life might have been different without it? If your parents didn't do it to you, what are your impressions on the experience of not being lied to when most other children are?
Also, I promise to upvote anyone who links to an easy to register for community of conspiracy theorists where they would not be averse to being asked the same question.
Deception of children for the purpose challenging them to spot the inconstancy is common practice in my experience. In this case though the inferential distance seems like it would be way to large to overcome with out additional evidence. The additional evidence is often the parent taking on a different tone of voice and method of reasoning while presenting faked evidence. Which makes it hard to tell if the parent is going too far in this example.
If the purpose of this system is what it does, POSIWID, then this tradition of deceiving often trains children to look for verification of presented evidence, trains them not to take one data point too seriously, as well as to not always to take what is said at face value no matter who says it.
Ideally the deception would be just the right inferential distance to stretch the child maximally while still being able to overcome it.
Some people are bound to participate in the tradition with out understanding its purpose and achieve ill results. As is with participating in any tradition with out understanding what its results commonly are.