Non-clinical causes of poor progress in development of cognitive abilities and in learning activity of schoolchildren have been studied. It is assumed that retarded intellectual development and lagging behind at school is basically a result of initially defective system of communication with adults. Such communication causes deformation of the motivational sphere in the child and developes in him inadequate attitudes to learning situations (the latter are products of the mechanism of psychological defense activated in order to decrease the level of neuroticity). However positive changes in communication with such children may result in improved behavior, in elimination of defense mechanisms, and -finally - in increased level of intellectual development and better marks at school.