ASSESSING INTELLIGENCE IN CHILDREN: A RESEARCH STUDY ON TWINS USING THE K-ABC

The authors examine the development of cognitive functions in the twin population in order to verify the interpretation of data widely reported in the literature, indicating a tendency to cognitive inferiority. According to Zazzo a methodological error needed to be corrected. This error had led some people to assume, based on this presumed “cognitive deficit”, that twin populations were racially inferior. The aim of this study is to respond to this need by using an innovative instrument to evaluate intelligence, together with a scientifically solid theoretical frame which was not available to the eminent scholar. The test used was the K-ABC, which fits in with Luria’s neuropsychological theory and measures and expresses cognitive functioning in terms of Mental Processes according to two “operative styles”: one characterized by linear (Sequential) connections, the other by connections going in different directions at once (Simultaneous). This study was conducted on a substantial sample consisting of 50 pairs of twins and 100 non-twin children. This multiphase research has yielded interesting data regarding twins: a normal development of Sequential Processes, and a slower development of Simultaneous Processes. The data interpretations take into account the test’s theoretical framework, Zazzo’s twin studies, and current research on mirror neurons. In twins, the pair effect would appear to favor a normalization of Sequential processes, whose function it is to codify objects and connect actions together (thereby compensating relational deficiencies with parents), but to hinder other relational and “social” experiences, implying that there are fewer possible confrontations and that there is less need for the synthesizing skills which are typical of Simultaneous processes. The aim of the research was reached: our results invalidate the hypothesis of a link between “a statistical tendency to cognitive inferiority” in twin populations and the type of multiple birth (and conception) involved; any risk of racist argumentation is therefore averted. Furthermore, twins would appear to benefit from an enhanced pair relationship. An unexpected but interesting piece of data, which we believe is important, emerges from the study and indicates that in cognitive development, the “genetic” factor interacts with the relational according to two distinct modalities: the pair relationship, which promotes and reinforces contact with the world, thereby activating sequential mental processes; and a broader, more “social” relationship soliciting and activating simultaneous processes. Such a result was obtained thanks to Luria’s theory, sustained by Kaufman’s test. It constitutes an original contribution to the understanding of the cognitive functioning in all individuals, and presents data which, if correctly interpreted, may help outline concrete investigative developments and, in problem situations, identify opportune human resources.