Working with data from the PISA study (OECD, 2007), Lynn (2010) has argued that individuals from South Italy average an IQ approximately 10 points lower than individuals from North Italy, and has gone on to put forward a series of conclusions on the relationship between average IQ, latitude, average stature, income, etc. The present paper…

The Ravens Standard Progressive Matrices Test was administered to 48 subjects who then performed a card-sorting task under single- and competing-task conditions. Hick's Law and the Roth-Jensen procedure were used in task development. Complexity should have a more central role in speed of processing models of intelligence than ability to divide…

Three studies of college students found a sex difference in the correlation of memory scanning rate, short- and long-term components of free recall, and word recognition with memory span. Findings are discussed in terms of prior work and a theory presented to account for the obtained sex differences. (Author/RD)

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…