Piaget and Inhelder defined uneven developmental progress of specific cognitive abilities as a decalage (1969). Psychiatrists must often help patients deal with a decalage across lines of de-velopment. Although this is largely devoted to the expla-nation of normal development, there has been a systematic effort to illustrate how deviations in development may lead to the onset of developmental psychopathology. Normality can be defined as a multilineal progression of development without a decalage, or unevenness of progress, across any of the primary domains of function. Normal children learn to think, to make friends, to deal with intense affects, and to honor the customs of their society. Problems occur when development is uneven. The patterns of these interlineal decalages are varied and their complexity is in large part one of the persistent areas of fascination for psychia-trists. To illustrate this process, two straightforward decalages are discussed. Finally, a more complex example of a severe arrest in development is presented.
Cognitive delays can result in a decalage in which a teen-ager has the mental capacity of a second-grader while having the sexual urges and emotional swings of a normal adolescent in high school. The cognitive ability of such a teenager may not be per-ceived as abnormal in the context of a protected classroom. How-ever, within the general population, he will be clearly labeled asdeviant and will be at high risk for experiences that will place him in jeopardy for negative social and academic outcomes. Be-yond dealing with the obvious limitations in achievement, there are also emotional risks to be considered if intellectual limita-tions cannot be placed within a context that protects such an ado-lescent from ridicule and humiliation.
Emotional delays provide a similar potential for a variety of decalages. A child who is cognitively normal or even preco-cious may remain emotionally immature. The decalage can be widened if intensive academic effort and subsequent successes become the predominant strategy that the child develops for deal-ing with social awkwardness or peer rejection. Temper tantrums that were expected in the early years become less easily tolerated in the child “genius’’ who repeatedly demands to have familyand social events orchestrated on her or his terms. In more severe cases, frustration and despair may interfere with adaptation in the same way that they do in the child who is cognitively delayed.
If a domain of function becomes arrested, the decalage becomes more severe. In these cases, overt psychopathology often results. A clear example is the development of conduct disorder and, subsequently, antisocial personality disorder. In these individuals, physical, cognitive and social developments appear to be progressing well, but a specific deficit in the development of moral judgment occurs. In some cases, the deficit is best described as the persistence of an immature sense of right and wrong, but in other adolescents there is a deviant development of amorality that is abnormal at any stage of development. Given the resistance of adults with antisocial personality disorder to current treatments, there is a strong case for focusing on the origins of this developmental decalage with the expectation that earlier intervention may be more effective than later efforts to treat.