Article originalSeverity of the autistic disorder and organization of socio-cognitive skills: differentiation or dissociation
Introduction
In his latest book, Jacques Lautrey (2003) suggests that researchers should reconsider the epistemological bases of differential psychology: “a dynamic approach to individual differences including the study of intraindividual changes occurring in the course of the years and the study of differences in the way individuals change leads to the study of differentiation process”. Our research is within this framework. The study of pathological functioning and that of developmental disorders contribute to the development of a differentiation psychology “that would stand for the differential psychology what developmental psychology stands for child psychology”.
All evolution, all progress or development, is a transition from the homogeneous to the heterogeneous. This general law, proposed by Spencer in the mid-nineteenth century, obviously governs human mental development, which Spencer spoke of as a progression from the simple to the complex, through successive differentiations. Spencer’s model was to become the framework for describing the gradual differentiation of abilities during child development. A century later, Garrett (1946) and Burt (1954) reapplied this model to the study of the development of intelligence. In Garrett’s (1946) terms, intelligence changes its organization as age increases; starting as a general and unified ability, it becomes a composite group of several factors or abilities. Thus, at certain times, adaptive behavior is the outcome of procedures of a broad scope, while at others, it depends of skills of a much narrower span (Reuchlin and Bacher, 1989). As such, development is not linear; it follows a spiral-like course. Every time a new form of intelligence develops (sensorimotor, representational or symbolic, etc.), a differentiation process takes place (Molenaar et al., 1993, Molenaar and Raijmakers, 1999). Differentiation is always followed by a variable-length period of relative undifferentiation, during which cognitive abilities are not hierarchical, adaptive behaviors are very general, and certain procedures can be implemented in different situations: a child who succeeds or fails in solving a given problem is likely to succeed or fail in solving other problems to which he/she is subjected.
Research in this field (Lienert and Crott, 1964, Reinert, 1970, Baltes et al., 1980, Deary et al., 1996) has shown that the differentiation process grows during childhood and adolescence and then starts to decline in the forties. More specifically, until the age of 6 or 7, we find differentiation of abilities, in particular, verbal ability. Between the ages of 7 and 10, during the elementary school years, we find a phase of gradual integration of abilities characterized by an increase in a general factor. Then comes another differentiation phase, through pre-adolescence, with verbal ability losing its integrating role. This is when the ability to reason emerges, gradually expanding its role and contributing to a larger and larger number of tasks until it becomes a general integrating factor of the logical reasoning type. The importance of this general factor continues to rise until the end of adolescence (Nguyen-Xuan, 1969, Fitzgerald et al., 1973, Atkin et al., 1977, Olson and Bergman, 1977, Weeks, 1980).
As such, the differentiation of abilities in the typical child seems to be the result of a higher-level, enhancing mechanism which, after a period of relative stability and global functioning, initiates a phase of gradual instability; this phase evolves in turn into a new period of stability involving consolidation and generalization of new schemes and new behaviors. These changes in cognitive organization occur under the influence of a number of developmental and contextual constraints (Pry et al., 1998).
At the observational level, and in a pluralistic view of intelligence and cognitive abilities (Carroll, 1993, Greenspan and Driscoll, 1997, Anderson, 1999), this spiral-like form of development is characterized in particular by an increase in the relationships between behaviors. The correlations observed can be explained by a general factor in the case of a factor analysis, or by the first component or axis in the case of a principal component analysis. In analyses with Varimax rotation, the differentiation hypothesis is validated if these factors approach orthogonality in certain increasing age brackets.
It seemed interesting to pursue this question by examining the organization of intelligence in children with a pervasive developmental disorder. The constraints imposed upon these children are probably very different from those that determine how typical children function. In addition, the severity of the autistic disorder could have an influence on the organization of the intelligence of those children and their psychological functioning.
Section snippets
Subjects
The participants in the study were from 49 child psychiatry centers in France that were contacted between December 1997 and December 1998. With parental consent, 193 children were included in the study. The eligibility criteria were (1) a diagnosis of pervasive developmental disorder (F84 in the ICD-10) and (2) age under 7 years. The mean age of the subjects was 5 years and the age range was 21 months–7 years. The sex distribution was unequal, with 81.3% boys and 18.7% girls (sex ratio:
Results
Table 3 presents the results of the factor analysis on the whole sample, based on the correlation matrix for the five psychological developmental scores.
Contrary to our implicit hypotheses, the group containing the most deficient children (low level of development, no speech, and high disorder intensity) was the group where differentiation was taking place. Two areas were beginning to be differentiated, one rooted in a cognitive factor that loaded object-related cognitions and person-related
Discussion
These two organizations of intelligence (differentiated and undifferentiated) do not have the same meaning in normal and in autistic children. They follow one another in normal development, whereas they seem to be deadlocked in autistic children with an approximate CA of 5 years.
The “autistic differentiation” was manifest in the most impaired children, for whom disorder intensity was the greatest, psychological development was highly retarded, and the clinical autistic characteristics were the
Conclusion
Impaired development as it is seen in infantile autism led us here to reexamine the concept of differentiation. We saw that differentiation can be encompassing and enhancing, as it is in typical children where it supports the construction of new knowledge and the manipulation of new material. But it can also be reductive, even jeopardizing. In this case, it can be accounted for in terms of the “dissociation” of cognitive resources as a adaptive strategy, and as the expression of the pressure
References (36)
- et al.
Intelligence and the differentiation hypothesis
Intelligence
(1996) The Development of Intelligence
(1999)- et al.
Ability factor differentiation grades 5 through 11
Applied Psychological Measurement
(1977) Etude des facteurs d'évolution chez le jeune enfant autiste (Evolution Factor of Young Children with Autism)
(1997)- et al.
Life-span developmental psychology
Annual Review of Psychology
(1980) The differentiation of intellectual ability
British Journal of Educational Psychology
(1954)Human Cognitive Abilities: a Survey of Factor Analysis Studies
(1993)- et al.
Contextualism and developmental psychopathology
Development and Psychopathology
(1998) - et al.
Emergence of adult intellectual structure: prior to or during adolescence?
Developmental Psychology
(1973) - et al.
The Vineland Adaptive Behavior Scale in a sample of normal French children: a research note
Journal of Child Psychology and Psychiatry
(1993)