Time‐related effects on MMPI profiles of police academy recruits

Assessed secular changes in MMPI normative scores related to three developmental components: Age, year of birth, and time of measurement, in police academy recuits (N = 1119). Assessment involved two‐way univariate analyses of variance to test for changes in MMPI scale scores laid out in three bifactor models: Age × year of birth (cohort‐sequential), time of measurement × year of birth (cross‐sequential), and age × time of measurement (time‐sequential). Age and year of birth did not affect MMPI scale scores. Time of measurement affected 9 of 13 scale scores (L, F, K, HS, PD, PT, SC, MA, and SI). From 1964‐1971 a gradual mild drift was noted wherein more “symptomatology” and less “defensiveness” was reported, although not of clinical significance. After 1971, an abrupt reversal was noted. The significant environmental change that occurred in early 1972 and that may have been powerful enough to influence approach to the test was the police department's hiring of a consultant clinical psychologist.