After dwelling on the importance, both theoretical and practical, of the relative frequency of neurotic difficulty in young children, Dr. Isaacs proceeds to classify and analyse some 400 letters, selected from a total of 572 received by her as advisory correspondent to a weekly paper read chiefly by mothers and others concerned with nursery problems. She quotes from a considerable number of the letters.

Theoretically, she points out, the importance of frequency lies in the check it places on the assumption that a definite line can be drawn between the 'normal' and the 'abnormal'. Neurosis in childhood is a matter of degree. Almost all children produce some neurotic symptoms between the ages of 2 and 6 years. The practical importance of frequency is in its bearing on diagnosis and treatment.