This chapter consists of two relatively independent parts. One concerns the relation between aggressive antisocial behavior and testosterone, the other the relation between the same or related behavior patterns and adrenaline. In many ways these relations are quite different, but there is a common denominator in that both parts refer to an association of hormonal factors with aggressive antisocial behavior. In addition, the empirical results presented are based on the same sample of healthy male adolescent subjects. The study of the adrenaline – behavior relation has not been reported before. Basic information on the testosterone study can be found in other publications (e.g., Olweus, in 1983; Olweus, Mattsson, Schalling, & Löw, 1980). In this chapter, some new analyses of testosterone – behavior relations will be presented in a causal analytic framework.

Testosterone

Relatively recent studies of the relation between plasma testosterone levels and aggressive antisocial behavior in the human male have yielded somewhat conflicting results (for references, see Olweus et al., 1980). However, when combined with findings of animal studies (e.g., Moyer, 1976; Rose, 1975), the empirical results on human males suggest that there may be a positive relation between plasma testosterone levels and one or more aspects of aggressive, impulsive, and antisocial behavior patterns. For animals, the findings also indicate that testosterone may have a causal influence on some forms of aggressive behavior. This, of course, does not preclude the possibility that an individual's testosterone level is affected by environmental and experiential factors (including the individual's own behavior).