Experiences in prenatal life and early childhood that may cause personality disorders or criminal behavior in later life are examined in these proceedings of the Subcommittee on Childhood Experiences as Causes of Criminal Behavior, of the Standing Committee on Health, Welfare and Science, Senate of Canada. This issue, the eighth in a series of 19 hearings dating from Novmeber 1977 to July 1978, presents expert testimony by Dr. Ronald Trites concerning the relation to criminal behavior of brain dysfunction, hyperactivity and drug abuse in children. His view is that there is no single cause of criminal behavior, and that geographical study of the prevalence of patterns of aberrant behavior among children in a set region will contribute to an understanding of the antecedents of criminal behavior. He emphasizes that there is no simple, one-to-one relationship between brain dysfunction and criminal behavior, and that the strongest claim that can be made about hyperactivity is that it is a risk factor for anti-social behavior. Following a brief prepared statement by the witness, subcommittee members asked questions about the following: the causes, diagnosis and treatment of hyperactivity; the adequacy of present research funding; the cause of recent increases in crime; and the relation of autism and learning disabilities to criminal behavior. Dr. Trite's single recommendation to the committee was to support long-term funding of research and treatment programs in Canada. A copy of Dr. Trites's brief for the committee, including references and tables, is provided in the appendix. The text of the hearings is presented in both English and French. (Author/SS)