There are ten points of interest in the results. First, the IQ in the northern regions of Italy measured by the PISA data is approximately 100 and therefore about the same as in Britain and other countries of northern and central Europe [...]. This confirms the results of the standardization of the Colored Progressive Matrices in northern Italy reported by Prunetti [...] and shows that IQs measured by the PISA data and by the Colored Progressive Matrices data are consistent. Regional IQs in Italy decline steadily through the central regions and into the south and reach a low of 89 in the most southerly region of Sicily. The first hypothesis of this study that there may be a north–south gradient of IQs in Italy is supported and quantified by the correlation of 0.963 between regional IQs and latitude.
