Sure, I'm not saying parents have to come running every time or anything. The point is that letting a kid cry until he goes back to sleep is consistent. Locking your kid in a box to see what happens is not. How will the kid know next time he gets stuck, that it's not just another test? And since the kids are still learning how to communicate, adding a continuing doubt that maybe their parents understand them fine but have chosen to ignore them isn't going to help.