Factorial Invariance of Ability Measures in Groups Differing in Intelligence and Socioeconomic Status

Scores on 12 aptitude and achievement tests for 11,743 subjects, subdivided into four groups according to intelligence and socioeconomic status, were used. A technique, developed by Jöreskog, for simultaneously factor analysing data from several populations was used to determine whether there was factorial invariance over the four groups. A model, in which the same factor pattern (matrix of factor loadings) is assumed to hold for the four groups, was fitted to the data. Goodness‐of‐fit indices suggested that the model fitted satisfactorily. Differences in the factor dispersion matrices and mean factor scores for the subpopulations are then examined and discussed.