As outlined by Dr. Peter Gray, the play is a vital part of us growing as a species, through play we learn crucial skills, we learn to grow. For instance, if kids are allowed to go out and play, they might get hurt by climbing a tree, but by getting injured they learn not to that again, they also learn how to climb a tree,  however if a parent told the kid not to go climb the tree because they might get injured the kid will listen to that command, they will not ever climb a tree because they fear getting injured and as a result they won’t ever learn how to climb a tree again. Now, climbing a tree is not necessary skill for a species like us humans, but that is not the point, the point is for them to go out and do what they want, they need to learn that they free to do whatever they want in life, they are not to cautionary words like, “don’t do that”, or “it’s impossible” they need to learn for themselves, For example, going back to the tree analogy, the kid who climbs the tree and gets hurt, might gain a new skill: risk management. By risking getting injured they can have fun. Just like that, risk management is now a concept implanted in their young brains. If kids with the skill of risk management continue to play they will foster the growth of the skill even more until that skill becomes a part of their own natural way of thinking. In contrast the kid who never climbs the tree never gets the skill, at an early age, it might be even more difficult for them, because unlike the kid who climbed the tree, they are bound to words like, “don’t do that”, or “it’s impossible”, they will be subject to the words that other people tell them. To sum up, the kid who climbs the tree, is above the words of caution.