This is a problem usually associated with the diagnosis of ADHD. Children not only have difficulty in school to absorb the contents of lessons delivered to them, but at the reading room or at home, are not able to put your mind in focus which is really important, so they can not advance their materials or classes or taking the best of wishes to catch up with a book or notebook with a partner.
This has been catching on, especially since the issue of competitiveness is fashionable. It is true that a happy child is not one who knows and that the best notes are removed, but no less frustrating for you, wanting to learn, is unable to attend and concentrate on what is taught. Self-esteem is a matter quite associated with personality, but so low in these children's self-concept. The "how others see me." It is not able to know what I want, and otherwise is to know less than they do others. This is where lies the importance of treatment. Not because there simply to be the best, but because the child also want to satisfy their own achievements, and, knowing intelligent, he is not able to implement this intelligence, because it can not archive what matters, what really matters for to advance.
This is also seen in the daily life of the workforce. Especially when there has been a history of childhood. This is today called attention deficit in adults, and should be treated similarly to children.
On the other hand, is the emotional level. This complicates performance in children and in adults, and should be evaluated very precisely, so that you know when the emotional pain is the cause of devolution and inattention.