This question is for a friend of mine whose son is 2 years old and not turning 3 until November. She is getting implications from her daycare that a big reason for her son's behavioral issues is because he is still sleeping in a crib at his age. Mind you, he is a wild child...and a climber...and she is working on getting him into a toddler bed but she has never heard anything about pro-longed crib use making kids behave badly. Nor have I. I would not consider this prolonged either. I have know people keep their kids in a crib until way past 3.