If there's one thing to be learned from Christmas, it's that kids are Machiavellian little monsters who only care about presents. If you had any doubt about that, this video from Distractify will prove it to you, using the cold hard science of a lie detector.*
In the clip, kids are hooked up to a polygraph machine and interviewed by the operator and a curiously young Santa Claus who doesn't even do a voice. The kids' responses varied between lying about having good intentions, and being shockingly honest about their greed for toys. It was a good time for everyone.
*Note: lie detectors are notoriously unreliable.