Porteus Maze Test performance of retarded young adults and nonretarded children.

Performances of retarded young adults on the Porteus Maze Test were compared with those of first- through fourth-grade nonretarded children. The retarded subjects, approximately matched on MA with the fourth-grade group, performed at the level of the first graders and were reliably poorer than the third and fourth graders. This MA lag of at least 2 years is consistent with the MA lag previously found on strategic games and puzzles. The retarded and first-grade groups spent more time completing mazes than did the other groups.