In a cross-sectional study five groups of male recruits (n = 369; ages 21 to 36) to a large English provincial police force were tested: one group at entry, three groups at different stages of their 2-year probationary period (one at one-quarter, one at one-half and one at three-quarters of the way through) and one immediately after the probationary period. Significant group effects were found on all 27 items of a set of self-concept statements, suggesting effects of entry-level occupational socialization on recruits' self-image. Changes from group to group during the course of training were examined using discriminant function analysis. Factor analysis yielded four clusters of items: isolation/vulnerability, tension/apprehension, self-worth and commitment/empathy; scores on all four fluctuated during training. Isolation and apprehension rose from a low base during training, and self-worth fell from a high base, but entry levels were recovered by completion of training, giving support for a weak version of the U-curve hypothesis of adaptation. However, high levels of commitment and empathy at entry were significantly depressed on completion of training. In addition, older trainees reported lower self-worth and higher apprehension. Results are interpreted in terms of adaptation during occupational socialization towards a more instrumental and cynical operational style.