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Biomedical subjects

L G Humphreys

Publications and source records attributed to L G Humphreys.

6 recordsLinked to original sources

Utility of predicting group membership and the role of spatial visualization in becoming an engineer, physical scientist, or artist.

This article has two themes: First, we explicate how the prediction of group membership can augment test validation designs restricted to prediction of individual differences in criterion performance. Second, we illustrate the utility of this methodology by documenting the importance of spatial visualization for becoming an engineer, physical scientist, or artist. This involved various longitudinal analyses on a sample of 400,000 high school students tracked after 11 years following their high school graduation. The predictive validities of Spatial-Math and Verbal-Math ability composites were established by successfully differentiating a variety of educational and occupational groups. One implication of our findings is that physical science and engineering disciplines appear to be losing many talented persons by restricting assessment to conventional mathematical and verbal abilities, such as those of the Scholastic Aptitude Test (SAT) and the Graduate Record Examination (GRE).

Adolescent↗

Assessing spurious "moderator effects": Illustrated substantively with the hypothesized ("synergistic") relation between spatial and mathematical ability.

The traditional methodology for assessing moderator variables (hierarchical multiple regression analysis) is examined. Possible drawbacks of this technique for corroborating psychological theories (cf. Busemeyer & Jones, 1983), are illustrated empirically on the basis of an analysis of 400,000 subjects. This article tested a well-known (and currently popular) substantive hypothesis: A synergistic relation exists between mathematical ability and spatial visualization in the prediction and development of sophisticated levels of advanced mathematics. Using the traditional methodology, this hypothesis was confirmed; however, on further analysis, using a more systematic approach, it was demonstrated that this finding was spurious. Suggestions are offered for modifying the traditional methodology used for assessing moderator effects (for both applied and theoretical purposes). These amount to ways for minimizing Type I and Type II errors.

Adolescent↗

Longitudinal correlation analysis of standing height and intelligence.

Intercorrelations of 10 successive years of measurement of height and intelligence are presented for separate samples of girls and boys. These correlations are based on data originally gathered and published by Dearborn, Rothney, and Shuttleworth as the Harvard Growth Study. Sample size varies from correlation to correlation, but most of those for girls are based on samples of 500-700 and those for boys on samples of 400-500. The intercorrelations of each of the 2 variables over 10 occasions do not differ appreciably by sex, but there are significant differences between the sexes in the cross-correlations. For the sample of girls there is clear evidence that individual differences in height at 8 and 9 anticipate later individual differences in intelligence. Correlations of early height with intelligence at 11 and 12 are especially high (.40). There is little evidence for similar anticipation of intelligence by height for boys. Correlates for both height and intelligence are found in socioeconomic status, ethnicity, and age of first menstruation for girls. Only the last of these contributes to the explanation of the changes in the cross-correlations with age. Analyses of sitting-height correlations with intelligence indicate that length of the long bones of the legs is also related to the observed pattern of correlations.

Adolescent↗