Is the act of the parents - that of going along with cultural norms of faux-deceit - still evil if it actually makes their children better able to succeed socially? Where does the 'evil' lie?
Yes. Other-optimising and deliberately changing someone's map so that it doesn't reflect the territory are hard to make a case for. "Cultural norms" is not such a case. I am not convinced there are people who actually learn how to play better when they don't know the rules of the game.
I am not convinced there are people who actually learn how to play better when they don't know the rules of the game.
Assuming your position holds given the language I used as well as with your framing then we have an unambiguous disagreement in matter of fact. If you see things the way they actually are you have to lie. People are just not that good at double talk. I will not begrudge those who work best at navigating a world of bullshit by immersing themselves in it the opportunity to play to their strengths.
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.