Also, the deep interest in reading which typifies the gifted child may further his isolation. Irwin believes that reading should be deferred in the education of the highly intelligent. "I believe it is especially important that intellectual children get a grasp on reality through real experiences in making and doing things before they are ever introduced to the wonders that lie within books." From this point of view, the development of the physical, social, and emotional aspects of personality would have first attention in the education of a gifted child, the intellectual being fostered last of all because it comes of itself and is too likely to run away with the other three and lead to isolation. This tendency to become isolated is one of the most important factors to be considered in guiding the development of personality in highly intelligent children, but it does not become a serious problem except at the very extreme degrees of intelligence. The majority of children between 130 and 150 IQ find fairly easy adjustment, because neighborhoods and schools are selective, so that like-minded children tend to be located in the same schools and districts. Furthermore, the gifted child, being large and strong for his age, is acceptable to playmates a year or two older. Great difficulty arises only when a young child is above 160 IQ. At the extremely high levels of 180 and 190 IQ, the problem of friendships is difficult indeed, and the younger the person, the more difficult it is. The trouble decreases with age because as persons become adult, they naturally seek and find on their own initiative groups who are like-minded, such as learned societies. THE CONCEPT OF "OPTIMUM INTELLIGENCE" All things considered, the psychologist who has observed the development of gifted children over a long period of time from early childhood to maturity, evolves the idea that there is a certain restricted portion of the total range of intelligence which is most favorable to the development of successful and well-rounded personality in the world as it now exists. This limited range appears to be somewhere between 125 and 155 IQ. Children and adolescents in this area are enough more intelligent than the average to win the confidence of large numbers of their fellows, which brings about leadership, and to manage their own lives with superior efficiency. Moreover, there are enough of them to afford mutual esteem and understanding. But those of 170 IQ and beyond are too intelligent to be understood by the general run of persons with whom they make contact. They are too infrequent to find many congenial companions. They have to contend with loneliness and with personal isolation from their contemporaries throughout the period of immaturity. To what extent these patterns become permanently fixed, we cannot yet tell.