Sex differences on the Progressive Matrices are influenced by sex differences on spatial ability

The Progressive Matrices Test (PM) is considered an excellent measure of general intelligence or g. There are several studies showing that, on average, males score higher than females on the PM. However, some investigations have demonstrated that there are no sex differences in g. Why are there these contradictory findings? The visuo-spatial format of the PM could be favourable to the male performance, because (on average) males score higher than females on overall spatial ability. The present study administered the Advanced Progressive Matrices Test (APM) and the Spatial Rotation Test from the Primary Mental Abilities Battery (PMA) to a sample of 239 university undergraduates. Males outperformed females on both tests. However, the male advantage on the APM turned out to be non-significant when sex differences on spatial rotation were statistically controlled. It is suggested that sex differences on the PM could be a by-product of its visuo-spatial format.