Structure of intelligence in intellectually precocious children and in their parents

Students representing the top 0.03% of their age group in intellectual ability, who were identified by the Study of Mathematically Precocious Youth (Benbow & Stanley, 1980), were tested along with their parents using a battery of specifically designed cognitive tests. These highly intelligent children had less intelligent, but yet quite bright parents. Vernon's (1961) model of intelligence best fits our results. His following two factors explained most of the variance in the performance of the students and parents: verbal-educational and practical-spatial-mechanical. Moreover, there was potential evidence for a general factor. Among the children, who were mostly past puberty, age related to development of verbal abilities, but not spatial or mechanical abilities. Sex differences favoring the males were found on the spatial ability and mechanical comprehension tests.