The question was raised whether tests of abstract ability were valid for cross-cultural comparisons. The first group of Ss consisted of 27 boys, about 15 years of age, from the Accra urban area, all of whom received the Goldstein-Scheerer Cube Test. The second group consisted of 317 boys who received the Raven Progressive Matrices Test on three successive weeks. The third group consisted of 32 boys who took the Kohs Block Design Test, administered and scored according to McConnell. The results showed that the cube Test performance is affected by environmental influences, and that the Progressive Matrices is susceptible to practice effects. Paradoxically the third group did about as well as McConnell''s Ss on the Kohs Blocks who were shown to perform at a level comparable to Wechsler''s standardization group. It was concluded that tests of abstract ability are no more "culture-free" than tests of intelligence. 30 references.