Both intelligence and educational attainment are strongly determined by the same genetic factors [...], and where there are large population differences in intelligence and educational attainment there is a probability that genetic factors are involved. In the case of Italy, it is known that the populations of the north and south differ genetically. Cavalli-Sforza, Menozzi, and Piazza (1994) are the leading authorities on the genetics of human populations, particularly those in Italy. They write of the population genetics of Italy that "northern Italy shows similarities with countries of central Europe, whereas central and southern Italy are more similar to Greece and other Mediterranean countries. This corresponds to the well-known differences in physical type (especially pigmentation and size) between the northern and north-central Italians on the one side and southern Italians on the other". By "Mediterranean countries" Cavalli-Sforza, Menozzi and Piazza mean the countries that border the Mediterranean including those of North Africa and the Near East. They note also that the Sardinians are genetically more closely related to the Greeks, Lebanese and North African Berbers than to central and northern Europeans [...]. Subsequent studies have confirmed the genetic impact of immigration from the Near East and North Africa into southern Italy. For instance, the Taql, p1 2f2-8-kb allele has a high frequency in the Near East and North Africa (Morocco, 81.8; Lebanon, 43.7; Tunisia, 34.1). The allele is also present but at a lower frequency (26.4) in southern Italy, including Sicily. The frequency of the allele falls to 14.1% in central and northern Italy, but the allele is rare at 3.8% in France and 3.5% in the Netherlands [...]. A similar gradient is present for the pYa1 allele which has a high frequency in North Africa represented by Egypt (85.0), a lower frequency in southern Italy (includes Sicily and Sardinia) (70.5), falling to 51.4 in north-central Italy, and falling further to 33.0 in England [...].
