As stated at the outset, the aim of this analysis is not to demonstrate that IQ in Southern Italy is the same or higher than that in the North. On the other hand, a simple statistical exercise, based on correlations among variables, such as that by Lynn, is far from conclusive. Recent studies have shown a significant statistical relationship (p-value = 0.008) between the presence of storks in the European continent and the birth rate (Matthews, 2000); an association which seems particularly remarkable in the case of Germany (Höfer et al. 2004). We know how hard it is to explain causality by means of statistical exercises and certainly causal relationships are not captured by simple statistical correlations.
Our previous discussion suggests a different relationship among the variables analyzed by R. Lynn and those collected in the present article. Allowing that school tests are representative of differences in IQ, we have seen that:
- they clearly show how the North-South difference in cognitive ability does not exist at the age of 7. The correlation between regional educational achievement (INVALSI) and regional per capita income becomes positive (0.44) at the age of 10, but is, however, considerably lower than that found through PISA test scores;
- the IQ-average income relationship did not exist in the past, although if it had derived from a genetic difference, it would consequently have done so;
- knowledge of genetic differences in Italy does not support Lynn's opinion that peoples from North Africa and the Near East strongly influenced the genetic structure of the Southern Italian population. Genetically, the influence of the Phoenicians and the Near East populations accounts for a very small fraction, while the predominant genetic influence derives from the long phase of Greek colonization.
The existence of differences in IQ, as revealed by school tests and other tests (supposing that these actually reveal "fundamental" diversities in intelligence), seems much better explained as being socially, economically and historically influenced rather than being genetically determined. Capabilities in problem solving are enhanced by a developing and stimulating environment, according to the so-called "Flynn effect".
In the past, the Southern Italian economy has at times been more advanced than the Northern one; for example during both the Roman antiquity and the high Middle Ages. Perhaps the North and the Centre were more advanced than the South in the late Middle Ages; although nothing certain can be said on the matter. The following decline of the Italian economy as a whole, from the late Middle Ages until the end of the 19th century, probably cancelled the existing economic differences. When per capita GDP diminishes and approaches the level of bare subsistence, differences among regions disappear. In the 19th century, Italy was a relatively backward country both in the North and the South. The statistical material available from the end of the 19th century onwards, does not actually indicate a deep North-South divide, in economic terms. The start of modern growth from then on affected the North much more than the South and economic disparity began to exist between the two parts of the country. In 1891 the North-South difference in per capita GDP was less than 10 percent; it was 20 percent on the eve of World War 1, and 45 per cent after World War 2. In 2010, per capita GDP in the South is about 60 percent that of the North. As ordinarily happens, relative backwardness implies the accumulation of adverse influences. While literacy and years of education grew in the North with respect to the South, infant mortality diminished much more quickly in the North than the South. Institutions, including families and schools, work much better in prosperity than backwardness. Estimates of IQ are likely to be higher where families, municipalities, provinces and regions invest more in education. Remarkable emigration from the South to the North, especially between 1950 and 1975, increased the North-South diversity since emigration, in Italy as elsewhere, is always selective. Since IQ registers education and years of schooling to a greater extent than intelligence, the relative position of the South compared to the North deteriorated in both the cultural environment and the economy more or less contemporaneously.
Daniele and Malanima. "Are people in the South less intelligent than in the North? IQ and the North-South disparity in Italy". Journal of Socio-Economics, 2011.