Evidence for change in children's use of defense mechanisms.

Using a cohort-longitudinal design, children's use of the defenses of denial, projection, and identification was assessed at four points over a 2-year time span, covering the age period from 6 years, 6 months to 9 years, 5 months. The results showed a clear decrease in the use of denial from early to middle childhood, a sharp increase in the use of projection, and an increase in the use of identification. These findings, predicted by a theory of defense mechanism development, are consistent with cross-sectional results reported previously.