One hundred eighty one sets of black twins and 223 sets of white twins provided responses to four 12-item subtests of the Raven's Progressive Matrices Test, Standard Version. The children were in elementary school and their item response patterns were analyzed with the use of revised ordering-theoretic methods to search for best-fitting…

Groups of retarded and nonretarded children were investigated as they learned three rules underlying problems adapted from the Raven Progressive Matrices Test: rotation, imposition, and subtraction. Results were seen as consistent with theories that emphasize transfer flexibility as one potential source of individual and comparative differences in…