I found this question on Quora.
A lie-to-children is an over simplified statement as a starting point to get people to understand a concept.
Things like “the Earth is a sphere” when it’s really an oblong sphere. Or saying that a president is like a king. The difference doesn’t matter when you’re just starting out.
This is an appropriate lie to tell when parenting.
Sean’s answer highlights the grey zone when practicing to lie-to-children. His mom told him the right lie-to-children when he was young, but it was hard to proceed from there.
Other than these, it’s really not appropriate or helpful to lie to a child. A child is a person and deserves to understand what’s going on. So if you just don’t want to take your kid to get ice cream, you might choose to lie and say the ice cream store is closed. But it would be better to simply explain the real reason. “You’ve had too much sugar already.” “We cannot afford it right now, we’re saving up for something else.” “We can’t get ice cream every day.”
This may not be satisfactory to the child and they might get upset. That means more work for you, and that’s one of the reasons you thought about lying in the first place. Or it might make perfect sense to the child. It’s hard to guess. But either way, it’ll give them the raw fuel they need to develop into a better child and eventually a great adult.
Sam Harris’s short book Lying is a great run down of why lying is rarely the right thing to do. It covers lying to children around page 72.