ABSTRACT
This conclusion presents some closing thoughts on the key concepts discussed in the preceding chapters of this book. The book suggests that the characteristics of withdrawal, learning problems, and tall stature seen in boys with the 47,XYY karyotype are interrelated and in turn may produce increased frustration and temper tantrums. It illustrates the bidirectionality of phenotypic and environmental influences and suggests that the increased family pathology could be a result of the personality problems in the boys, as well as a cause. The book suggests that personality characteristics in 47,XXY males is secondary to cognitive problems. The study of variations in sex chromosome aneupioidies (SCA) can demonstrate the range and mechanisms of genetic effects on cognition and behavior, extending into the normal range. The studies of individuals with SCA stand in contrast to that detailed studies of cognition and personality are available and exemplify the international and interdisciplinary collaboration necessary to accomplish them.
