SEX CHROMOSOMAL ABNORMALITIES ARE FOUND MORE COMMONLY AMONG AGGRESSIVELY BEHAVED AND SEXUALLY DISTURBED PRISON INMATES THAN IN THE GENERAL POPULATION, WITH THE EXCESS VARYING BETWEEN 2 AND 10 PERCENT COMPARED TO THE GENERAL POPULATION. FURTHERMORE, MOSAIC CASES OCCUR IN PRISONERS IN WHICH VARYING NUMBERS OF CELLS ARE AFFECTED. BUT DUE TO VARIOUS PROBLEMS IN DERIVING NORMAL POPULATION SAMPLES AND DESIGNING MEASUREMENT PROCESSES, THESE DATA CANNOT BE EASILY INTERPRETED. ASCERTAINMENT AND SAMPLING REFERRING TO DEFINING ABNORMAL STEREOTYPES OF BEHAVIOR AND IDENTIFYING DISTRIBUTION OF CELLS IN THE BODY ARE THE MAJOR DIFFICULTIES. THE EPIDEMIOLOGICAL PROBLEM IS TO LOCATE INDIVIDUALS WITH A STANDARD PATTERN OF BEHAVIOR IN THE POPULATION AT LARGE OR IN SPECIAL INSTITUTIONS AND THE CYTOLOGICAL PROBLEM IS TO LOCATE CELLS OF A GIVEN KARYOTYPE IN PARTICULAR REGIONS OF THE BODY. METHODS OF ASCERTAINMENT AND SAMPLING, TO BE MOST USEFUL, MUST TAKE ACCOUNT OF THE LIKELIEST TIMES AND POINTS OF CONNECTION BETWEEN SOCIAL AND BIOLOGICAL FACTORS. SEXUAL ABNORMALITIES ARE THE EASIEST CHROMOSOMAL ABNORMALITIES TO STUDY BECAUSE THEY ARE COMMON, REASONABLY WELL SPECIFIED, AND HAVE A RECOGNIZABLE IMMATURE PATTERN. IF THE UNDERLYING EMOTIONAL CONFLICT IN CRIMINALS IS SEXUAL, THEN IT IS NECESSARY TO INVESTIGATE THE VARIATION IN SEXUAL DIMORPHISM IN THE LIMBIC SYSTEM AND NEUROENDOCRINE AXIS. THIS CAN BE DONE BY TESTING IMPULSIVE TEMPORAL LOBE EPILEPTICS CYTOGENETICALLY AND COMBINING THE FINDINGS WITH NEUROLOGICAL DATA ON UNILATERAL PREDOMINANCE. THE RESULTING GRAPH WOULD SHOW TWO GROWTH DEFECTS, ONE DEPENDENT ON GENETIC SEX, THE OTHER ON LATERALITY. CLINICALLY, IT APPEARS THAT TEMPORAL LOBE EPILEPTICS, IN WHOM BEHAVIORAL SYMPTOMS ARE PREDOMINANT, DESERVE CYTOGENETIC DIAGNOSIS AS PART OF ROUTINE MANAGEMENT, AND THAT THEIR FAMILIES, TOO SHOULD BE INVESTIGATED. IMPLICATIONS FOR MEDICINE AND RESEARCH ARE DRAWN, AND REFERENCES ARE PROVIDED. (DAG)