The inquiry was conducted in two stages: (1) a preparatory stage for the development of relevant hypotheses for the design of the strategy of investigation and for the construction of the necessary measuring techniques, and (2) an investigation in which the yield from the preparatory work was used in a study of 1,565 London boys ranging in age from 12-17 years. A summary of the findings, which included but went beyond the presentation of the principal findings, stated that the evidence strongly supported the hypothesis that high exposure to television violence increased the degree to which boys engaged in serious violence. In addition, five types of television violence appeared to be the more potent in releasing serious violence by boys. In a commentary on the findings, it was hypothesized that a major operating mechanism of television violence was to reduce or break down those inhibitions against being violent that parents and other socializing agencies had been building up (disinhibition). It was recommended that the total amount of violence presented on television be reduced, that long-term empirically established guidelines be provided to decide which type of violence should be most avoided, and that a continuing monitoring system be established to analyze the violence presented. Further research was suggested to study the psychological processes involved when boys are influenced in some way by television violence, and to make a parallel study of adolescent girls. Extensive tables and a detailed description of the hypothetico-deductive method used in the study are given. Tables, notes, and appendixes are given.