Temperament at 4 years: The contributions of handedness, gender and IQ

Abstract

The relationship between cerebral lateralization and temperament, and the role of gender and cognition in this relationship were examined in 39 normal 4-year-old children. Cerebral lateralization was measured by combined indices of child, parental, and familial handedness (combined familial handedness). Temperament was measured by the mood and approach/withdrawal subscales of the Behavioral Style Questionnaire derived from Thomas and Chess at al (1963). WPPSI-R vocabulary and block design subtests. were used to generate a full scale IQ score. There were 20 boys and 19 girls. Lateralization alone, as measured by combined familial handedness was not associated with temperament. Combined familial handedness interacted with gender to predict temperament, and combined handedness interacted with IQ to predict temperament. However, gender and IQ themselves did not interact in the prediction of temperament from combined handedness. Thus, gender and IQ seem to exert separate influences in the relationship between handedness and temperament. Whereas both left-handedness and female gender are factors promoting greater symmetry, in these data, either one or the other of these factors was an advantage for mood, but the two together became a disadvantage. Cognition is a very influential factor for combined left-handedness, but not for right-handedness, in detecting the relationship between and temperament. High IQ with left-handedness is an advantage for both mood and approach. Laterality as measured by combined handedness tells us nothing about temperament until it is paired with other influences such as gender and IQ. Laterality thus, is a complex, flexible system, highly susceptible to other dimensions of brain organization. Although the variables of gender, IQ, and temperament have previously been examined in relation to cerebral latereralization in adults, to date this is the first study to examine the interaction of all these variables and to apply this model of hemispheric specialization to young children. In general, the findings suggest that children and adults are similar in the organization of cerebral lateralization.