Lynn (2010) suggests that differences in average intelligence explain many of the differences observed across the Italian regions. This paper puts forward a methodological critique to his study, coupling it with an empirical test showing that Lynn's analysis is not sufficiently robust to support its conclusions. (Contains 2 tables.)

Beraldo (2010) and Cornoldi, Belacchi, Giofre, Martini, and Tressoldi (2010) (CBGMT) have eight criticisms of my paper (Lynn, 2010) claiming that the large north-south differences in per capita income in Italy are attributable to differences in the average levels of intelligence in the populations. CBGMT give results for seven data sets for IQs in…

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…

Prior studies found individual differences in visual recognition memory during infancy were related to individual differences in later intelligence. This paper discusses methodological issues in the measurement of infant visual recognition, the significance of previously obtained predictive validity coefficients, and the theoretical question of…

In 2 studies with 85 and 88 undergraduates, respectively, peripheral nerve conduction velocity (NCV) was significantly correlated with IQ score and reaction times, and NCV and reaction time contributed significantly, in combination, to prediction of IQ. Results are interpreted in terms of a neural efficiency model of intelligence. (Author/SLD)

The authors discuss methodological and theoretical issues in psychological investigations of infant attention, fixation times, habituation, and intelligence. A consensus on how to measure individual differences in habituation has not been reached. The relation between IQ and attention is discussed. (RD)

Sources of continuity among nine measures of infant cognitive processing and later childhood intelligence quotient were examined through developmental structural equation models applied to a sample of 208 twin pairs measured from 7 to 36 months. Skills assessed appear related to general cognitive ability in a relatively unstable manner. (SLD)

Two methodological issues involved in determining the relationship between learning and general intelligence were examined: (1) the use of learning strategies in a paired-associate task and (2) the importance of time (rather than errors) in the measurement of learning efficiency. (Author/RD)

This study investigated the relationship between measures of speed of cognitive information processing and intelligence test scores. Cognitive processing measures were significantly related to IQ scores. Reaction time tests measure cognitive operations basic to intelligence, and individual differences in intelligence are partly due to variability…

Interrelationships among IQ, academic achievement, and teacher ratings of pupils' classroom achievement were evaluated in a large sample of children from various racial and socioeconomic backgrounds. A substantial relationship between standardized measures of IQ and achievement was found and was independent of race, but decreased with increasing…