Using three temperamentally different subgroups from a large birth
cohort, the authors undertook a longitudinal study of the association
between temperament measured in children at 4 and 8 months and IQ assessed
at 4.7 years. The data suggested a strong effect of extreme temperament
traits on IQ development in middle and upper socioeconomic classes and in
families with superior functioning in terms of communication. The
temperamentally difficult group unexpectedly displayed higher IQs, and the
well-replicated effect of socioeconomic status on IQ development was
observed mainly in this group. These data support the hypothesis that
difficult infants activate special family resources, which stimulates
intellectual development over the years.Abstract Teaser