Studies have shown that intelligent children are more likely to lie
In "Political Animals", they related a study done on gorillas that had been trained to speak via sign language. What they found was that they basically communicated like toddlers. When one of them pooped in the middle of the main "lobby" of the facility where the gorillas interact with the researchers, one of the scientists asked who had pooped in the middle of the lobby, and the gorilla tried to blame one of the research assistants, then another one, before the scientist managed to put enough pressure on the gorilla to make him confess.
The basic gist of the chapter was on how human evolution favored both good liars and people who were good at discerning who was lying, both of which come with intelligence. Stupid children will lie, but an intelligent child will be able to figure out when to lie and how to get away with it, while a stupid child just gets caught every time, and usually learns it's not worth trying.
You reminded me of an experiment I was once shown in a Child Development class where they place a cup filled with rocks upside down on a table and tell the kid not to touch it and go away and see if the kid disrupts it and what excuses they make up. Some of the excuses were pretty funny. My parents actually did that kind of test on me when I was little by putting a bowl of my favorite candies and then counting later to see if I took any. I didn't, but that might have been because I knew I would be too dumb to get away with it. lol.
T-This... erm...Loves the can?Oh...What's with that can there?Zuikaku!Oh, you won't say?Secret!Even to me...Even to Kaga-shan!Ahahaha!
Is that so?Loves this can!What do you want to put in that can?Okay, I'll give it to you, Zuikaku-chan!Really!?Thank you, Akashan!It's nothing.Won't say!