A RANDOM SAMPLE OF 200 Z TESTS (100 MALE, 100 FEMALE) FROM THE APPLICATIONS OF 3304 PROSPECTIVE INSTRUCTORS FOR SUPERVISED INSTRUCTION FOR JUVENILES BETWEEN 1951 AND 1967 IS ANALYZED TO DETERMINE (1) THE TYPICAL PROFILE OF APPLICANTS IN THE SURVEYED PERIOD OF TIME, (2) PERSONALITY TRAITS WHICH APPEALED TO THE PSYCHIATRISTS IN CHARGE OF THE PRESELECTION PROCESS, AND (3) THE PERSONALITY DIFFERENCES BETWEEN SUCCESSFUL CANDIDATES WHO LEFT THE FIELD OF SUPERVISED INSTRUCTION AFTER A SHORT TIME AND THOSE WHO REMAINED IN THE FIELD FOR AT LEAST 8 YEARS. THE STATISTICAL ANALYSIS INDICATED THAT THE AVERAGE APPLICANT IS CHARACTERIZED BY ADOLESCENT TRAITS UNJUSTIFIED BY AGE, BY ORAL FIXATIONS, BY NEUROTIC INHIBITIONS AFFECTING THE USE OF THE INTELLECT, AND BY A PENCHANT FOR IDENTIFYING WITH OTHERS. OTHERS. IN PRESCREENING THE CANDIDATES, THE PSYCHIATRISTS SHOWED A PREFERENCE FOR APPLICANTS WITH STRONG EGOS AND SUFFICIENT CONTROL OVER THEIR ANXIETIES. SUCCESSFUL APPLICANTS WHO REMAINED IN THE FIELD OF SUPERVISED INSTRUCTION WERE DISTINGUISHED BY A REALISTIC ATTITUDE, FEW INHIBITIONS IN CREATIVITY, CONSIDERABLE AMOUNTS OF ANXIETY, A TENDENCY TOWARDS AN 'INTERIOR INSECURITY SYNDROME,' AND RELATIVELY WEAK EGOS. THERE WAS LITTLE CORRESPONDENCE BETWEEN PROFESSIONAL SUCCESS AND A FAVORABLE PRERATING. IT IS THEREFORE SUGGESTED THAT A MORE COMPREHENSIVE AND CONSTRUCTIVE SELECTION PROCESS BE USED. THE ARTICLE CONTAINS EXTENSIVE BACKGROUND MATERIAL, CHARTS ON THE STATISTICAL TEST ANALYSIS, AND FOOTNOTES. --IN FRENCH. (SAJ)