A study (sorry, lost the link) claims to have found the importance of a development step in childhood, or rather the importance of a delayed brain development. The frontal cortex is responsible for many high level brain activities. They say that it triggers any behavior outside the norm, any action not following a given pattern. The development of this region of the brain is not finished in young age. This prevents a child to take risks by striving around too much, and it also keeps them on the tracks of a language while learning to speak, speeding up the learning processes using drill routines.
However, they give the following example: Assume a reward is hidden with chance 2/3 behind the red door, and with chance 1/3 behind the blue door. An adult will soon start to mimic these chances, choosing the red door 2/3 of the time. And, of course, this will miss the optimal strategy. A child, however, is unable to choose a different selection each time, and will start to choose the red door every time, which is the correct strategy.