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 third in a series of 19 hearings dating from November 1977 to July 1978, presents expert testimony by Dr. John D. Atcheson concerning the childhood experiences that lead to development of psychopathic personalities and what society can do to improve the social environment or influences that breed the psychopathic personality. Dr. Atcheson's thesis is that crime is a bio-psychosocial phenomenon, and that understanding it requires consideration of a combination of factors such as the following: genetics, nutrition, sensory experience, critical periods, maternal condition and care, learning disabilities, emotional security, parenting patterns, and cultural controls and belief systems. Dr. Atcheson emphasizes the importance of predictable parenting and emotional security of the child. He suggests that school systems teach general principles of personality development in an attempt to modify parenting patterns. Other topics discussed include cultural comparisons with the Canadian Inuit culture, the effects of day care on young children, and the availability of group homes for children in Canada. The testimony was presented in the form of a prepared paper and responses to questions from subcommittee members. Both English and French texts are provided. (Author/SS)