A follow-up of mental defectives after eighteen years.

Development, drop, and death.

“…Considerable evidence has been accumulated on the dependency of developmental changes on the original level of functioning (Berkowitz & Green, 1965;Birren & Morrison, 1961;Granick & Friedman, 1967;Miles & Miles, 1932;Riegel, 1968;Schaie & Strother, 1968;Vernon, 1947), indicating a better maintenance of performance for subjects with superior abilities. Below average or inferior subjects, on the other hand, have often been found to show slower growth, lower peak performances, and more rapid deterioration during later years of life (Bailer, Charles, & Miller, 1967;Kaplan, 1943Kaplan, , 1956Kaplan, Rambaugh, Mitchell, & Thomas, 1963;Muench, 1944; counterevidence by Bell & Zubeck, 1960).…”

Chapter II: Mental Development during the Preadolescent and Adolescent Periods

“…As noted in Chapter I, several factors in the environments of those who had shown the most significant changes were studied. Muench (37) located and retested a group of boys living in the city of (Columbus, Ohio) who had been diagnosed as mental defectives in the Opportunity School eighteen years previously. On the Stanford-Binet, Porteus Maze, and Army Alpha he found a statistically significant increase.…”

What is a moron?

“…In spite of his low intelligence he has relatively good judgment, common sense, understanding, insight, foresight, prudence, and those other qualities which make for social independence and which are so conspicuously lacking in the genuinely feebleminded person. The intellectual moron, therefore, is socially sufficient and socially self-sustaining even though his station in life may be somewhat humble because of his limited intellectual endowment (21). What is even more important is that in the intellectual moron, the low verbal intelligence as measured by the Stanford-Binet may be offset in large measure by a nonverbal type of intelligence which may approximate the average, especially if supported by favorable personality traits such as industriousness, initiative, altruism, which qualities are usually lacking in the typically feebleminded person.…”

“…Whatever mental test devices are employed, it is evident that the intellectual moron and the social moron are both of low literate-verbal intelligence and that consequently there is much overlapping between the upper limits of feeblemindedness and the lower limits of normality as measured by such tests. This range of overlapping is so great that the upper limit of feeblemindedness on some tests may even approximate the quartile limits of the normal distribution, while the lower limits of normality may approximate the lower moron limits (4,21). It is fair to say from the experimental literature on the subject that at least on the Binet Scale the social moron and the intellectual moron completely overlap with, of course, comparatively few normals reaching the lower limits of normality and comparatively few morons reaching the higher levels of dull-normality.…”