Generally speaking, Lynn is not to be trusted. He's been caught numerous times falsifying and manipulating data to fit his conclusions (e.g. here, here, here, here, here and here), and it looks like he's up to his old tricks again.
This time around, he's not even using actual IQ data, but the proxy of scores on reading, math and science tests administered to 15-year-olds (PISA 2006). So he's attempting to quantify innate general intelligence by looking at the academic performance of school kids, a measure that to a large extent involves learned knowledge and other factors. Indeed, while some researchers report a strong correlation between general intelligence and educational attainment, one of Lynn's own sources, Deary et al. (2007), addressing two of his other sources, suggests that caution should be exercised when attempting to equate the two:
There are various possible causes of the cognitive ability-educational achievement association. Bartels et al. (2002b) found a strong genetic correlation between cognitive ability (measured at 5, 7, 10, and 12 years) and educational achievement at age 12. In an overview, Petrill and Wilkerson (2000) concluded that genetics and shared and non-shared environmental factors all influence intelligence and education, with genetics being important in the correlation between them, and non-shared environment being important in discrepancies between intelligence and educational attainments.
Whereas the correlations indicate that around 50% to 60% of the variance in GCSE [General Certificate of Secondary Education] examination points score can be statistically explained by the prior g [general intelligence] factor, by the same token a large proportion of the variance is not accounted for by g. Some of the remaining variance in GCSE scores will be measurement error, but some will be systematic. Thus, non-g factors have a substantial impact on educational attainment. These may include: school attendance and engagement; pupils' personality traits, motivation and effort; the extent of parental support; and the provision of appropriate learning experiences, teaching quality, school ethos, and structure among other possible factors (Petrides, Chamorro-Premuzic, Frederickson, & Furnham, 2005; Strand, 2003).
But Lynn already knows the pitfalls of his approach. Finland had the highest score in Europe on the 2006 PISA tests, and using his method leads to a calculated IQ of 107, yet he reports Finns' IQ as being just 97. Romanians' PISA score is near the very bottom of Europe, leading to an estimate of 85, though their measured IQ is in fact 94 according to Lynn, just three points lower than that of Finns. With discrepancies like that, there's absolutely no reason to trust his calculated IQs of around 100 and 90 for Northern and Southern Italians. Clearly, PISA scores are not a good substitute for IQ.
Then, to try to prove that disparities in intelligence are long-standing, and therefore genetically based, he uses literacy as another (questionable) proxy for IQ. But whereas for other correlates like stature and infant mortality he includes data from the past and present to show that the North-South gap has remained fairly stable, for literacy he only includes data from 1880, when it was extremely large (55% vs. 20%, on average). Obviously, he wants to hide the fact that the gap has been closing steadily since then, and by the 21st century, literacy among Italians under the age of sixty-five was 99.7% in the North and 99% in the South (Istat 2001).
Lynn goes on to attempt to correlate his fake IQs with achievement. The primary measure he uses is per capita income, which is double in the North what it is in the South. His source is the Italian Statistical Office, but he should be aware that figures for the South's economic performance are greatly underestimated because the official statistics fail to take into account a large underground economy there, according to Burnett and Vaccara (1999):
But the third factor, somewhat alleviating the second, is the existence of a far vaster private sector than ever shows up in the economic statistics. The size of the lavoro nero sector and the black market in the South clearly exceeds that of any other EU region.... In Calabria, with its dire employment figures, 84 percent of the families own their own home. What such anomalies must mean is that real income in Calabria is far higher than what is "on the books." Many among the vast numbers of officially unemployed are, in fact, partly or fully employed. They are earning no social benefits, but they are earning the daily lire that keep their families afloat. [...] A very large part of the South's hidden labor is made up of entrepreneurs, sometimes also employing black labor, and existing themselves outside official recognition, taxation, protection, control, or counting. A recent analysis concludes that "there exists in several zones of the Mezzogiorno [Southern Italy] a whole fabric of small and very small businesses that escape every census, but that work and make profits, share among themselves a serious level of production, export to other regions [of Italy] and abroad." [...] This massive sector skews all the statistics. It means that the GDP for the Italian South (and for Italy as a whole) is far from accurate. And the unemployment figures do not reflect reality.
Then, with the same goal of establishing a pattern that extends far back in time, he also looks at historical achievement, citing Charles Murray's Human Accomplishment. But here again he plays fast and loose with the data. He adds up Murray's "significant figures" for Italy from 1400-1950 and divides them into "North", "Center" and "South" based on their origins. Almost all of them (187 out of 236) come from the "North". However, he explains that he uses the 42nd and 41st lines of latitude as borders, which are, respectively, just north of Rome and just north of Naples. So more than half of the country is put into the "North" category, while the "Center" gets flattened down and pushed into the territory of the "South" (click here to see what that looks like). This is a shameless and transparent ploy by Lynn to hugely inflate the number of significant figures from the "North" and reduce the number elsewhere in the country.
But perhaps even worse, he ignores the main finding of Murray's book, which is that achievement has been concentrated in just a few places, and Southern Italy is but one of many "low-achievement" areas throughout Europe, along with some of the northernmost regions in Italy:
As you can see — and as Murray points out in his book — the highest ranking region is Tuscany, which would normally be considered part of Central Italy. Ironically, Lynn doesn't even have PISA/IQ data for Tuscany, though its 1880 literacy rate isn't particularly high. So he's basically attributing the unique genius of that region to the brainpower of regions that have not produced the same level of genius.
Finally, Lynn offers his "explanation" for the disparities in fake IQ, which, unsurprisingly, turns out to be admixture from the Middle East and North Africa, where (according to him) IQs are in the range of 80-84. As you might expect from someone with an agenda and little knowledge of genetics, he references a lot of old studies that use single or small numbers of loci and don't directly address the question of admixture. One of them has "Neolithic demic diffusion in Europe" in its title, yet he stupidly follows the citation with references to historical groups like Phoenicians and Arabs.
Recent genome-wide studies have been able to detect and quantify admixture like never before. Li et al. (2008), using more than 600,000 autosomal SNPs, identify seven global population clusters, including European, Middle Eastern and Central/South Asian. Contrary to Lynn's claims, it's actually the overachieving Tuscans who have a small amount of non-European admixture and not the underachieving Sardinians:
López Herráez et al. (2009) typed the same samples at close to 1 million SNPs and analyzed them in a Western Eurasian context, identifying a number of subclusters. This time, all of the European samples show some minor admixture. Among the Italians, Tuscany still has the most, and Sardinia has a bit too, but so does Lombardy (Bergamo), which is even farther north:
The bottom line is, we don't know the average IQs for different regions in Italy, which is why Richard Lynn had to resort to making them up. And while Southern Italians are likely to be a few points lower than Northern Italians — as the Irish and Scottish are a few points lower than the English — there's absolutely no reason to believe that North and South would be separated at their extremes by almost a full standard deviation. Lynn certainly hasn't proven anything of the kind with this ridiculous study, nor has he provided any valid explanations for such a disparity.
Since I wrote this article, a number of studies have been published that refute Lynn and confirm what I've said (Last update: December 27, 2012):
- Cornoldi et al. (2010) and Sergio Beraldo (2010)
- Felice and Giugliano (2011)
- Daniele and Malanima (2011)
- D'Amico et al. (2012)
- Cornoldi et al. (2013)
Richard Lynn. "In Italy, north-south differences in IQ predict differences in income, education, infant mortality, stature, and literacy". Intelligence, 2010.