Advanced progressive matrices and sex differences: Comment to Mackintosh and Bennett (2005) Roberto Colom ⁎ , Francisco J. Abad Facultad de Psicología, Universidad Autónoma de Madrid, 28049 Madrid, Spain Received 30 June 2006; accepted 30 June 2006 Available online 10 August 2006 Abstract Mackintosh and Bennett's [Mackintosh, N. J. and Bennett, E. S, (2005). "What do Raven's Matrices measure? An analysis in terms of sex differences." Intelligence 33: 663–674.] study shows that males outperform females in some APM items but not in others, implicating that these items are measuring discriminable mental processes. The present comment was motivated by the fact that the sample size considered by these authors was small, thus raising the possibility of a lack of reliability. To replicate their findings, data from the Abad et al.'s [Abad, F. J., Colom, R., Rebollo, I., & Escorial, S. (2004). Sex differential item functioning in the Raven's Advanced Progressive Matrices: Evidence for bias. Personality and Individual Differences, 36(6): 1459–1470.] study were re- analyzed, but following the same criteria employed by Mackintosh and Bennett. The results are not consistent with those reported in their study, indicating that average sex differences remain fairly constant across the same groups of APM items considered by them. © 2006 Elsevier Inc. All rights reserved. Keywords: Intelligence; Sex differences; Advanced progressive matrices test There are several studies wondering whether or not males and females differ on average in the Progressive Matrices (PM) test. However, the number of studies focusing on the Advanced Progressive Matrices (APM) test is much smaller. The meta-analysis reported by Lynn & Irwing, 2004 considers studies published between 1939 and 2002 of whom nine (from Argentina, Belgium, France, Hong Kong, Singapore, Spain, and the United States) used the APM. The average sex difference computed from these studies was equivalent to approx- imately 4.7 IQ points (d = .31). Abad, Colom, Rebollo, & Escorial, 2004 found a male advantage equivalent to 4.03 IQ points, whereas Colom, Escorial, & Rebollo, 2004 reported a male advantage equivalent to 4.3 IQ points. Mackintosh & Bennett, 2005 showed a higher average male advantage equivalent to 6.4 IQ points, although the interesting point of their study was that males' better performance was statistically significant for some groups of items only. These authors classified the items according to the rules proposed by Carpenter, Just, & Shell, 1990 showing a male advantage in the rules addition/sub- traction and distribution of two. However, the sex difference in the rules pairwise progression and distribution of three was not significant. They concluded that “if there is a difference between male and female performance on one type of item, but not on another, then the two types of items must be measuring or engaging at least partially discriminable processes and operations” (p. 670). Intelligence 35 (2007) 183 – 185 ⁎ Corresponding author. Tel.: +34 91 497 4114. E-mail address: roberto.colom@uam.es (R. Colom). 0160-2896/$ - see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.intell.2006.06.003