IQ Test Scores Research Articles

Differential reproduction: its relation to IQ test score, education, and occupation.

Abstract The correlations among IQ test score, educational attainment rating, socioeconomic status, total number of children in the family of origin, total number of offspring in completed families, and mean age at birth of live‐born children are examined for a representative sample of the Minnesota white population. Natural selection appears to be favoring an increase in the mean IQ score in the sample, or at least there is no evidence for a decrease. The data show positive marital assortment for IQ score and for educational attainment. Four estimates of the heritability of the phenotype “IQ test score” coincide well with each other. The value of h2 estimated from parent‐children regression is 0.631; from a weighted regression of children's scores on the score of the father alone, it is 0.668 and on the score of the mother alone, it is 0.654. The estimate from the intra‐class correlation of full siblings is 0.666.

Relationships of Field-Dependent and Field-Independent Cognitive Styles to Creative Test Performance

138 undergraduate males were administered individual and group measures of perceptual field-independence. Most Ss were also administered two measures of intelligence and a battery of tests of creativity. Comparisons were made of the creative test performance of 3 groups of 15 Ss each, matched for Otis IQ and drawn from field-dependent-, field-central-, and field-independent- S categories. Similar comparisons were made with independent groups drawn from the same perceptual orientation groupings. It was predicted that field-independent Ss would obtain higher scores on tests of creative ability than would field-dependents. A significant relationship was also predicted between Ss' scores on the individual and group measures of field-independence. Individuals with field-independent cognitive styles were consistently more creative on the tasks used in this study than individuals with field-dependent orientations. Significant differences between the creative test performance of these two groups were obtained in both matched and independent group comparisons. Relationships between creativity and intelligence were weak and typically nonsignificant. Factor analysis of all test scores for 114 Ss revealed six creativity factors and one factor composed of IQ and perceptual test scores. Significant relationships were found between individual and group measures of field-independence. Both measures of perceptual-field orientation were significantly correlated with factors commonly measured in intelligence tests. However, the degree of association between field-independence and IQ was influenced by the loadings of quantitative factors in the operational measures of intelligence employed. Some of the theoretical implications of these findings are discussed.

Parental correlates of child's IQ and height: a cross-validation of the Berkeley growth study results.

In recent years there has been increasing interest in the degree to which environmental pressures and events can influence both IQ level and IQ change during the childhood years (2, 6, 8, 9, 11). Most investigators have reported an average correlation of .50 between the IQ of the school age child and the IQ of the parent (3, 5, Io), and this finding has often been interpreted as indicating the influence of genetic mechanisms on intelligence test performance. However, the size of these correlations leaves much variance to be accounted for, and there are data to suggest that environmental variables may also influence IQ score. Eels and Davis (6) have reported positive correlations ranging from .20 to .43 between socioeconomic level and various IQ test scores. One interpretation of these correlations is that the child in a middleor upper-class home is more apt to encounter verbal stimulation and encouragement of language skills than a child from a lower class family. It is assumed that this middle class emphasis on language development facilitates IQ score. Kagan and Moss (8) have found that parental attitudes do influence early IQ, for ratings of maternal concern with intellectual development were positively correlated with the IQ of the 3-year-old child when maternal IQ was held constant. However, the controversy over whether IQ is determined by nature or nurture seems less intense now than it was a decade ago. Psychologists are beginning to address themselves to a more plausible question: namely, to what degree and in what ways do genetic and environmental variables influence IQ score.