Ten, we consider finally the how the regional differences in IQs in Italy can be explained. The regional differences in IQs in the British Isles and France can be reasonably explained by a tendency of the more intelligent in the poorer regions to have migrated over the course of centuries from the provinces to London and Paris [...]. This would have raised IQs in the capital cities and reduced IQs in the provinces. In the United States also there has been migration from the poor south to the more affluent north that has likely been selective. It is probable that something similar has occurred in Italy, although most of the migration from the poor south was to the rich north rather than to Rome which is situated in the center of Italy. Putnam [...] describes migration from the south from the 1890s onwards as "substantial" and states that between 1958 and 1963 approximately 7% of the population of the south migrated to the north. Some political scientists have considered the possibility that outward migration from the south could have been selective. For instance, Putnam [...] writes that "it could be argued that selective migration could account for the backwardness of the south" although he does not mean selective migration for intelligence but for "civic mindedness" which he considers the crucial advantage of the northern population.
