IN 1962, A STUDY WAS CONDUCTED IN COPENHAGEN, DENMARK, THAT HAD AS ITS OBJECTIVE THE DETECTION OF CHARACTERISTICS WHICH DISTINGUISH CHILDREN WHO AT SOME LATER POINT IN THEIR LIVES BECOME SCHIZOPHRENIC. THIS EXAMINATION RESULTED IN A LARGE POOL OF DATA COLLECTED AT A TIME WHEN THE CHILDREN HAD NOT YET EVIDENCED ABNORMAL BEHAVIOR. IN 1975, THE CHILDREN HAD A MEAN AGE OF 28 YEARS. SINCE THE 1962 ASSESSMENT, MANY OF THEM HAD EVIDENCED A VARIETY OF MENTAL ILLNESSES. IT IS BELIEVED THESE DATA CAN ALSO BE USED TO DESCRIBE THE PREMORBID CHARACTERISTICS OF INDIVIDUALS WHO HAVE EVIDENCED FORMS OF DEVIANCE OTHER THAN MENTAL ILLNESS. SINCE 1962, MANY OF THE 311 SUBJECTS HAVE BEEN CONVICTED FOR HAVING COMMITTED CRIMINAL ACTS. THE FOUR PAPERS FOLLOWING THIS INTRODUCTION CONSIDER WHAT EARLY CHARACTERISTICS DISTINGUISH THE INDIVIDUALS WHO LATER BECAME CRIMINAL. THE SUBJECT OF EACH OF THE PAPERS IS BRIEFLY DESCRIBED. FOR DISCUSSIONS OF THE PREDICTIVE FACTORS OF CRIMINALITY, SEE NCJ 47294-47297. (RCB)