Introduction to Biological Issues, with Neuropathological Case Illustrations

Achievement of the ultimate, though still distant, goal of model building can benefit from clinical and biological data, even when the constraints imposed by such data (e.g., small samples) preclude statistical significance. The explanatory power of a model that accommodates such constraints is further enhanced when these clinical-biological data are placed in the context of known basic patterns of biological functioning. A comparison between animal and human sexual behavior is considered an intermediary bridge between social-psychological and biologically based studies. Nadler’s study of sexual aggression in the great apes found increased initiation of copulation (“aggression”) under “free access” conditions, where males and females were locked in one cage. From this observation he extrapolates to the human species, concluding that “the potential for male sexual aggression is inherent in our species,” and that such aggression is likely to be expressed under social, cultural, and environmental conditions that “reduce the female’s prerogatives for refusing sexual overtures.” He regards human sexual aggression as neither inevitable nor justified. It would appear that in humans the “pressure” from drives serving the survival of the species is less than the pressure from drives serving the individual’s survival. Langevin and his co-workers discuss the correlation of sadism with biological factors. They report on certain patterns of endocrinological abnormalities in sexual aggressives: the weak androgen, DHEAS, and cortisol tended to be higher, and prolactin tended to be lower in sexual aggressives than in controls. As has been found in other studies, testosterone levels were not significantly different between these groups. With regard to brain abnormalities, Langevin’s findings with CT scans suggested the involvement of two brain systems. The right temporal horn was dilated in sadists more frequently than in other sexual aggressives and in controls. Also, some EEG findings suggested temporal lobe epilepsy. These researchers are planning MRI studies to differentiate implicated brain systems. Freund considers the hypothesis that abnormal human sexual behavior (voyeurism, exhibitionism, toucheurism, frotteurism, preference for rape) constitutes a distortion of a phase of “courtship behavior.” He cites as the best-supported hypothesis for the