Identification and the development of competence: a 44-year longitudinal study from late adolescence to late middle age.

The role of defense mechanisms in the development of planful competence (J. A. Clausen, 1993) was studied over a period of 44 years in participants from the Oakland Growth Study, who are part of the Intergenerational Studies of the Institute of Human Development. Planful competence was assessed on 4 occasions, from late adolescence (ages 15-18) to late middle age (age 62). The use of the defense mechanisms of denial, projection, and identification was assessed in late adolescence, based on Thematic Apperception Test (H. A. Murray, 1943) stories coded with the Defense Mechanism Manual (P. Cramer, 1991b). In late adolescence, the defense mechanism of identification was found to be positively related to competence, whereas the less mature defense of projection was related to lower levels of competence. For the group as a whole, hierarchical linear modeling (Bryk & Raudenbush, 1992) indicated that competence increased across the adult years, with a modest decline at late middle age. Individual differences for intraindividual change in competence were related to the use of identification: high use of identification in late adolescence was associated with relative stability in adult competence, whereas low use of identification in adolescence predicted changes in adult competence.