Models of Educational Career With and Without IQ Measurements

Path models of educational careers do not usually contain information about phenotypical intelligence levels. This may lead to an overestimation of direct environmental effects such as the educational level of the parents on the education attained by the children. This phenomenon was investigated on the basis of data describing educational level, occupational status, and intelligence measurements of 2,847 father-son pairs. The IQ was determined during testing for military service by means of a shortened version of Raven's Progressive Matrices Test. The results were twofold. When the son's IQ was included in the model describing his educational career, environmental effects due to the influence of the father were reduced. Adding the father's IQ to the model, however, did not affect the path coefficients of the variables that were predicted to be relevant for the son's education.