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Socioeconomic disparity between North and South Italy has been recently explained by Lynn (2010) as the result of a lower intelligence quotient (IQ) of the Southern population. The present article discusses the procedure followed by Lynn, supplementing his data with new information on school assessments and per head regional income. Genetic North–South differences are then discussed on the basis of the most recent literature on the subject. The results do not confirm the suggested IQ-economy causal link.
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Are people in the South less intelligent than in the North?
IQ and the North-South disparity in Italy
Vittorio Daniele
a
and Paolo Malanima
b
The final, revised version of this paper has been published as:
Daniele V., Malanima P. (2011), Are people in the South less intelligent than in the North?
IQ and the NorthSouth disparity in Italy. Journal of Socio-Economics 40(6):844-852.
Working paper version
ABSTRACT - Socioeconomic disparity between North and South Italy has been
recently explained by R. Lynn (2010) as the result of a lower intelligence quotient (IQ) of
the Southern population. The present article discusses the procedure followed by Lynn,
supplementing his data with new information on school assessments and per head regional
income. Genetic North-South differences are then discussed on the basis of the most recent
literature on the subject. The results do not confirm the suggested IQ-economy causal link.
Key words: Intelligence quotient, Italy, regional disparities, school attainments.
Jel Classification: I00. I20. Z13.
a
“Magna Graecia” University of Catanzaro, Dopes Department, Viale S. Venuta, 88100 Catanzaro
Italy.
b
Institute of Studies on Mediterranean Societies (ISSM), National Research Council (CNR), Naples,
Italy.
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1. Introduction
In IQ and the Wealth of Nations, R. Lynn and T. Vanhanen (2002) claim that “the
intelligence of the populations has been a major factor responsible for the national
differences in economic growth and for the gap in per capita income between rich and poor
nations”(2002: xv). They retain that differences in per capita income among nations can
largely be explained by differences in national intelligence quotients (IQs). IQ accounts for
half the variance in per capita GDP among countries . Since, according to the authors,
national differences in IQs are partially genetic, the gap between rich and poor will be
impossible to eradicate (Lynn and Vanhanen, 2002: 195). In a subsequent book, Lynn and
Vanhanen (2006) expanded their initial sample of countries to include 192 nations, showing
the existence of an IQ-income per capita correlation of 0.60. Among other things, the
authors show how national IQs explain a series of social phenomena such as years of
schooling (0.64 correlation with IQ), life expectancy (0.77) and the degree of
democratization (0.57).
These results have been supplemented by Kanazawa (2006a, 2006b) and Whetzel-
McDaniel (2006), who maintain that the relationships singled out by Lynn and Vanhanen
(2002) between IQ, democracy and economic freedom are statistically significant and
robust. Recently, the existence of a link between IQ and economic performance has crept
into economics as well. By means of cross-country regressions, Weede and Kampf (2002)
found a strong, direct relationship between IQ and rates of growth, while Jones and
Schneider (2006) showed how the increase of 1 percent in national IQ implies a 0.11
percent increase in national rates of growth. Finally, Ram (2007) finds that the inclusion of
IQ in the Mankiw-Romer-Weil growth model raises its explanatory potential.
The thesis according to which IQ is the main factor explaining the different levels
of economic development has also been supported by research at a regional level. Lynn
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(1979) found a significant correlation between IQ and per capita income in the British Isles,
while McDaniel (2006) came to the same conclusion for the United States. This
relationship would extend to the macroeconomic level the strong correlation between IQ
and socioeconomic success existing at the individual level (Jencks, 1972; Irwing and Lynn,
2006; Strenze, 2007).
In 2000-05, in Southern Italy, where 37 percent of the Italian population lived, per
capita GDP was about 60 percent of that in the North (Daniele and Malanima, 2007). In a
recent paper, Lynn (2010) argues that the divide in per capita income and other
socioeconomic variables between North and South Italy depends on regional differences
in the intelligence quotient. According to R. Lynn, “regional differences in intelligence are
the major factor responsible for the regional differences in Italy in per capita income and in
the related variables of stature, infant mortality, and education” (Lynn, 2010: 94). Since, in
the opinion of the author, North-South differences in per capita income did exist in Italy
well before the 19th century, it seems logical to assume there to be some primary
determinant of such disparities. According to Lynn this divide originates from the North-
South genetic difference, which is the main determinant of the North-South difference in
IQ. Thus, synthetically: genes → IQ → North-South Italian divide.
In this article we start with correlations among variables concerning economy and
intelligence today; then we go back in time to discuss the relationship between economy
and IQ one century ago and finally we deal with the genetic heritage of the South of Italy.
The aim of our analysis is not to demonstrate that the IQ of the Southern Italian
population is the same or higher than in the North, but to test both the basic data and the
method followed by Lynn and subsequently to check if his data and procedure support the
conclusions drawn by the author. Since, as we will see, some simple facts neglected by
Lynn on the North-South socio-economic divide do not fit the set of relationships
established in his article, in conclusion we will propose a different, and, in our view, more
appropriate framework, to explain the links among the variables.
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2. The North-South Italian divide: methods and results
2.1. Measuring regional IQs
In his paper, Lynn (2010) assumes that interregional disparities in IQ are reliably
proxied by the statistics of the Program for International Student Assessment - PISA 2006 -
based on the results of 15-year-old students in tests on reading comprehension,
mathematical ability and the understanding of science (OECD, 2006). In his database, Lynn
averaged the results of the PISA 2006 tests concerning Italian regions and expressed them
“in standard deviation units in relation to the British mean”(2010: 96). These figures are
then converted into conventional IQs by multiplying them by 15. The result is that, while in
the North of Italy the level is 100 and thus equal to the British figure, in the South it is close
to 90, with Sardinia at 89. He then draws some conclusions on North-South economic
differences from the correlations between regional IQ and other variables regarding Italian
regions, both today and in the past. These variables concern stature in 1855, 1910, 1927,
1980, per capita income in 1970 and 2003, infant mortality in 1955-57 and 1999-2000,
literacy in 1880 and years of education in 1951, 1971 and 2001.
The correlation between IQ and the variables is higher than 0.74 and stays mainly
in the range between 0.85 and 0.95. IQ is therefore highly and positively correlated to per
capita income in 1970 and 2003, to years of education from 1951, and negatively, as
expected, to infant mortality from 1955 onwards. It is also positively associated to stature.
The health-stature-IQ correlation is explained by saying that more intelligent populations
“are more competent in looking after their babies, e.g. avoiding accidents, and are able to
give them better nutrition, which makes them healthier and more resistant to disease”
(Lynn, 2010: 97).
The use of test scores in mathematics and science to proxy national IQ is based on
strong evidence, such as that collected by Luo et al., according to which “individual
differences in mental speed are a main causal factor underlying the observed correlation
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between general intelligence and scholastic performance in children between the ages of 16
and 13” (Luo et al., 2003: 67). In a study based on data for 81 countries, Lynn and Mikk
(2007) found strong cross-country correlations between national IQs and mathematics and
science attainment. This study suggests that national IQs and educational attainment are
both indicators of mental ability of national populations. According to Rindermann (2007),
international and national assessment studies essentially measure the same thing as the
intelligence test: namely, a general intelligence factor.
A number of scholars have severely criticised the use of school attainment as an
estimate for IQ (Baumert et al. 2009). The reason is that IQ is, at least in part, a product
(rather than a cause) of school-related learning (Richardson, 2002). IQ calculated from school
tests captures not only intelligence, but years and quality of education, together with
environmental influences. We can suppose that the higher the age to which the school tests
refer, the higher the influence of all these secondary determinants on the primary cause of
difference that we wish to reveal (Richardson, 2002; Wilkinson and Pickett, 2007). As
shown by Marks (2007), IQ tests measure the degree of literacy much more than
intelligence. Growth of the average years of education explains the so-called “Flynn
effect”, that is the long term rise in IQ (Flynn, 1999).
2.2. Data and method
The database exploited in this article is reported in the Appendix (Table 1). The
series in columns 5-20 are the same as those in Lynn’s article. We have however, added
four columns to his series. We have supplemented PISA’s data with results of recent tests
by the Italian National Institute for the Evaluation of Instruction (INVALSI), based on a
wide sample of 1,100 primary classes distributed throughout all the Italian regions (Table 1,
cols. 1, 2). These data concern the assessment for mathematics in the 2nd and 5th classes of
the primary school. The enquiry by INVALSI has followed the methodology of similar
international comparative enquiries. In particular, tests in mathematics comply with the
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criteria already developed in international research on the theme by IEA-TIMSS -
International Association for the Evaluation of Educational Achievement, Trends in
International Mathematics and Science Study (Montanaro, 2008; Invalsi, 2009). The
INVALSI database has been utilized here to complete the documentary material exploited
by Lynn with information concerning average scores for the 2nd and 5th primary classes; that
is for children of between 7 and 10 years of age. These data refer to 20 Italian regions,
while the PISA assessment refers only to 12. However, in Table 1 data are reported
relating to 16 regions, which is the same sample examined in Lynn’s (2010) article. Two
other new series (cols. 3, 4) report data on GDP per capita in 1891 and 1911 (in 1911
prices) (Daniele and Malanima, 2007; Felice, 2007). We have established correlations
between data by Lynn and these recently published series. Since Lynn deals with the Italian
genetic and economic history, we tried to go back in time with our revision of his results.
We started by examining the correlation between INVALSI data and per capita
regional GDP in 2008, using data from the whole sample of 20 regions, in order to obtain
more robust relationships. Subsequently, the sample of 16 regions is considered to compare
our results with those attained by Lynn.
2.3. Results
Table 2 (Appendix) reports the descriptive statistics for maths scores: with the
exception of Sicily, all Southern regions exhibit similar or higher values than the national
mean. These data show how the standard deviation is relatively low for the 2nd class and is
increasing for the 5th class scores. Figure 1 illustrates the relationship between maths tests
scores and regional per capita income. It is easy to see that the relationship is not significant
(R2 = 0.03; p-value = 0.43), and the correlation is, in any case, low and negative (-0.18).
Three Southern regions Calabria, Puglia and Basilicata occupy the first places in the
hierarchy. Regional differences among children begin to appear in the 5th primary class, as
we see in Figure 2. The coefficient of determination is, however, low indeed (R2 = 0.15).
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The relationship is statistically not significant (p-value = 0.09), while the correlation
between variables is now positive (0.39) and higher than that for the 2nd class.
Figure 1. Maths test scores (2nd class) and per capita GDP (2008)
LAZ
FVG
LIG
MAR
LOM
BAS
ABR
CAL
EML
TOS
TAA
UMB
VEN
VDA
PIE
MOL
PUG
SIC
SAR
0
20
40
60
80
100
120
140
50 52 54 56 58
Math (II class)
GDP per capita 2008
Figure 2. Maths test scores (5th class) and per capita GDP (2008)
LAZ
FVG
LIG
MAR
LOM
BAS
ABR
CAL
EML
TOS
TAA
UMB
VEN
VDA
PIE
MOL
PUG
SIC
SAR
R2 = 0.15
20
40
60
80
100
120
140
45 50 55 60 65
Math (V class)
GDP per capita 2008
Note to Figs. 1, 2: PIE (Piedmont), LOM (Lombardy), VDA (Val D’Aosta), TAA (Trentino Alto Adige), VEN
(Veneto), LIG (Liguria), EML (Emilia), TOS (Toscana), UMB (Umbria), MAR (Marche), LAZ (Lazio), ABR
(Abruzzi-Molise), CAM (Campania), BAS (Basilicata), PUG (Puglia), CAL (Calabria), SIC (Sicily), SAR (Sar-
dinia). North includes the first 11 regions; South the other ones.
We will now examine the correlation between the INVALSI tests and the variables
used by Lynn in his investigation (for the sample reported in Appendix, Table 1). Table 3
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(Appendix) shows how the correlation between the tests for the 2nd class and per capita
output in 2003 is weak and negative (-0.18) regions with higher per capita GDP record
worse results in the tests. Maths tests for the 2nd class are also weakly correlated with maths
tests according to the PISA assessment (0.16), with mean instruction (0.16) and, as a
consequence, with IQ index as computed by Lynn. Correlations with the other variables are
weak or negative, the reason being that stature, infant mortality and average years of
education are endogenous to the level of regional development measured by GDP. These
variables exhibit very significant correlations with per capita GDP, but not with the results
in mathematics in the 2nd year of the primary school.
The case is different when we look at the correlation matrix for maths tests in the
5th class of the primary school that is at the age of 10. In this case, the relationship with the
PISA test, with years of education and with regional values of IQ, is significant (0.72). The
correlation with 2003 per capita GDP is relatively high (0.44), although considerably lower
than that with IQ. As expected, the results of the tests carried out on the 5th class students
are correlated with the variables investigated by Lynn, with the single exception of infant
mortality between 1955-57 (-0.26); although the correlation is lower than with the PISA
tests administered to 15- year-old students.
If we accept that the 2006 PISA assessment on IQ and the INVALSI tests assessing
the capacity of intelligence in problem solving are both reliable, then our provisional results
are as follows:
a. correlation with regional disparities in GDP is inexistent in the first years of school;
b. North-South disparities begin to appear in the last primary class (the 5th in Italy);
c. at the age of 15, these regional differences are visible and a relatively high
correlation exists between them and per capita income.
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2.4. Back in the past
In Lynn’s opinion, since the IQ of the Southern Italian population has not changed
over the last two centuries, a likely correlation could be supposed to exist between IQ and
data concerning the standard of living of past Southern populations. According to him,
“individuals and populations with a high IQ are able to work more efficiently than those
with a low IQ and consequently command higher incomes” (2010: 87). The main
correlation investigated by Lynn is that between IQ and per capita income.
We have already seen that a significant relationship exists between regional income
in 2003 and IQ as measured by PISA scores. In recent years, scholars went back in time
with their knowledge of per capita product. Research on Italian national accounting resulted
in the revision of data on Italian GDP in the years 1891, 1911, 1938 and 1951 (Conti
economici dell’Italia). Lengthy research into the industrial product by Fenoaltea (2001,
2003) and agriculture by Federico (2003b, 2003c) have enabled the reconstruction of
regional series for these two sectors of activity. Series regarding the service sector on
national and regional scales have also been produced (Felice, 2005a, 2005b). Until the last
decade, the opinion prevailed that at the date of national Unification in 1861, an economic
disparity already existed between Northern and Southern Italy. However, recent research
has revealed that at that time, agricultural output per head was slightly higher in the South;
industrial product was slightly higher in the North and services were more or less equally
present in both the North and South. Overall, as Fenoaltea (2006) stressed, a deep diversity
did not yet exist in the second half of the 19th century, and distribution of sectoral
employment, based on the first Italian national censuses from 1861 until 1911, confirms
this opinion (Daniele and Malanima, forthcoming).
Regional GDP from 1891 onwards has recently been reconstructed independently
by Daniele and Malanima (2007) and by Felice (2007), with similar results. According to
these reconstructions, in 1891 per capita GDP in the South was lower by 5-10 percent. It is
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plausible, but not certain, that in 1861, the year of Italian national Unification, the disparity
did not yet exist, or was modest, at least in per capita income. Italy was then a poor
agricultural country and areas of backwardness and prosperity existed both in the North and
South. An advanced and rich North did not yet exist at that time. In Italy, the increase of
literacy followed modern economic growth starting from the late 19th century. Although
regional differences in the levels of literacy existed during the period between 1870 and
1880, historians are doubtful about their significance. When referring to the Italian regions,
historians of literacy have often stressed that it is hard to distinguish the literate from the
illiterate merely by the ability to write one’s own name (Cipolla, 1969; Vigo, 1983; Lupo,
2005).
On the basis of this recent literature, it has become possible to test the regional
income-IQ relationship. Our correlation matrix, including data on regional income in 1891
and 1911, has been reported in the Appendix (Table 4). The correlation between data on
regional GDP per head and IQ is negative in 1891 (-0.13) and is not significant in 1911
(0.15). Our series show that the correlation increased year by year from then onwards. A
preliminary conclusion is that, in the half century after Unification, the (supposed) original
regional differences in IQs were not correlated to average regional incomes. Unfortunately
information regarding living standards in a more remote past and levels of average income
is not available. Historical literature suggests however, that for a lengthy period spanning
antiquity and the early and high Middle Ages, Southern Italy was more advanced than the
North (Malanima, 2002).
2.5. IQ and genes
According to Lynn, a genetic North-South difference is the main or unique
determinant of the relative backwardness of the Southern economy. Research on European
genetic structure has revealed or confirmed the genetic similarity of the European
populations and shown that Finns, on the one hand, and Italians, on the other, are the most
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atypical ethnicities in the continent. As for Italy, a further difference has been highlighted,
the Northern populations being more similar to the Europeans and the Southern to the
Mediterranean populations (Lao et al. 2008). The gradient between North and South, from a
genetic viewpoint, can be established in the Centre of the peninsula.
In their well-known work published in 1994, L. Cavalli Sforza, P. Menozzi and A.
Piazza stressed the North-South genetic difference in Italy, noting that “Northern Italians
are more similar to central Europeans whereas Southern Italians are closer to other
Mediterranean people, being darker and smaller” (Cavalli Sforza et al. 1994: 278). While
Northern Italian populations are genetically more similar to European peoples R. Lynn
states —, populations of Southern Italy share their genetic characters with “peoples from
North Africa and the Near East” (Lynn, 2010: 99), who immigrated to the South of Italy in
the distant past. Phoenicians, Carthaginians, Arabs are recalled by Lynn in his article as the
ancestors of present Southern Italians. The conclusion by Lynn is not totally new since, at
the end of the 19th century, C. Lombroso (1876), a little later A. Niceforo (1898) and, more
recently, F. Vöchting (1951) stated similar opinions. A consequence of this genetic
diversity is the difference in stature, which existed in the past and continues to exist today.
Despite the increase in stature both in the North and the South during the past century, a 2
percent difference in height remains (Federico, 2003a: 291). This difference in height is
correlated with socioeconomic disparities, in addition to possible differences in genetic
endowments (Arcaleni, 2006).
In his reconstruction, Lynn emphasizes the Phoenician and Arab genetic heritage of
the Southern populations. It is now known that from the Iron Age onwards, Southern Italy
underwent colonization first by Phoenicians and Greeks and later by the Arabs (9th-10th
centuries). Greek populations spread especially in Southern Magna Graecia and Sicily.
According to Piazza et al. (1988), towards 400 B.C., Greek inhabitants represented about
10 percent of the whole population living in the island, while the genetic influence of the
Phoenicians remained quite superficial: “whereas the Phoenicians directed their main
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colonizing efforts towards the coasts of North Africa, Spain, Malta, Sardinia and the
western triangle of Sicily, the Greeks settled mainly along the Southern and Western shores
of the mainland and also along the fertile coastal belt of Sicily” (Piazza et al.: 206). A high
percentage of Greeks also lived in Southern Italy (Piazza 1991: 67). It is not surprising that
the main genetic influence in the South is Greek, while the Phoenician influence is very
marginal. The case of Sardinia one of the Southern regions considered by Lynn is
unique: this region results as being genetically different from all other Italian regions
(Sicily included) (Piazza et al. 1988: 204).
For Sicily, a genetic map based on the variation of Y-chromosome lineages drawn
up by Di Gaetano et al. (2009), exhibits a genetic similarity with Greece. The homogeneous
distribution across the whole island of the haplogroup E3b1a2-V13 in particular, shows
how Greek colonisation resulted in genetic similarity between Greek and Sicilian
populations, while genes from North-West Africa are much less widespread on the island.
The conclusion of this research is that the genetic contribution of Greek chromosomes to
the Sicilian gene pool can be estimated about 37 percent, whereas the contribution of North
African populations is estimated to be around 6 percent. Can the Greek heritage to the
Western culture really be associated to a lower IQ?
3. IQ and the economy: a discussion
3.1. Intelligence, schooling and income
In the Italian case, the existence of regional differences in PISA and TIMMS scores
has already been analysed. For example, Montanaro (2008), by examining the TIMMS and
PISA results, notes that the family socioeconomic background significantly affects the
performance of students in these tests. In particular, in the first years of education, regional
disparities in test scores are very modest and concern primarily students with less
favourable family backgrounds. Other studies (Bratti et al., 2007; Checchi, 2007) show how
the North-South divide of Italian students’ ability in mathematics (as measured in PISA
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2003) is largely explained by factors related to regional socioeconomic environment, such
as school infrastructures and the local labour market, in terms of both employment
probability and the presence of irregular and illegal economies. Bratti et al. (2007) find that
about 75 percent of the North-South differential in mathematics is accounted for by
resource differences, while geographical differences in “school effectiveness” account for
the remaining share. Similarly, with respect to international studies that assign to the
environment a primary role in explaining differences in cognitive proficiency, national
studies also suggest that at the regional level when different socioeconomic conditions
exist a diverse performance in schooling test scores is influenced by environmental
factors.
The relationships between intelligence, schooling and income are complex since
each variable is linked to the others. The topic has been more widely discussed in
behavioural literature than in economic research. Ceci and Williams (1997) have shown
that variations in years of schooling are related not only to variations in intelligence and test
scores. “Some of the benefits that result from staying in school probably derive from its
indirect effect on intelligence, just as some of the contribution that intelligence makes to
earnings probably derives from its synergy with school-related variables” (Ceci and
Williams, 1997: 1057). Individuals can expect significant financial gains from extending
their education and even benefits in terms of health and life expectancy (Hanuschek, 2009:
41).
Recent studies show how not only the quantity, but also the quality of schooling
the cognitive skills , as measured by ordinary achievement score (such as TIMMSS or
PISA), plays a powerful role in individual earnings, aggregate income and economic
growth rates (Hanushek and Kimko, 2000). A research based on a large sample of countries
(Jamison, Jamison and Hanushek, 2007), shows that higher levels in the quality of
education (as measured by international student achievement tests) increase growth rates of
national income: depending on specific assumptions, the standard deviation by 1 point in
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test scores is correlated with a yearly increase in income per capita by 0.50.9 percent and a
similar increase in standard deviation in test scores is estimated to engender the decline in
infant mortality rates by 0.6 percent.
Developing countries lag dramatically behind developed countries both for quantity
and quality of schooling (or cognitive skills): “in many developing countries, the share of
any cohort that completes lower secondary education and passes at least a low benchmark
of basic literacy in cognitive skills is below one person in ten” (Hanushek and Woessmann,
2008, p. 657). These results are consistent with studies on Italy, that show how school
effectiveness and socio-economic variables, related to regional contexts, explain the North-
South differences in PISA scores (Bratti et al., 2007; Checchi, 2007)
3.2. Genes, socio-economic status and school achievements
At the individual level, the relationship between cognitive ability, as measured by
IQ, and education has been extensively analysed. For example, Jencks et al. (1972) reported
the existence of correlations ranging from 0.40 to 0.63 between cognitive test scores and
years of education. Mackintosh (1998) found in Britain a correlation of about 0.50 between
IQ scores of 11year-old children and later educational performance. Deary et al. (2007)
performed a longitudinal study of 70,000 English children examining the association
between psychometric intelligence at the age of 11 and educational achievement in 25
academic subjects at the age of 16. They found a correlation of 0.81 between intelligence
and educational achievement, with general intelligence contributing to achievement in all of
the 25 subjects under examination. Lynn and Mikk (2007) found a strong correlation
between national IQs, mathematics and science attainment and a number of economic and
demographic variables. Rindermann (2007) shows how IQ scores collected by Lynn and
Vanhanen are highly correlated with results from international school assessments. He
seems to share the opinion that “national cognitive ability”, is identical to general
intelligence.
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Turkheimer et al. (2003), show that the share of IQ variance explained by the genes
and environment is correlated to SES (Socio-Economic Status) in a non-linear way. Their
models suggest that in relatively poor families, 60 percent of the variance in IQ is
accounted for by the shared environment. In this case genetic contribution is close to zero.
In rich families, the result is almost exactly the reverse. The suggested explanation for the
lower ‘ability’ of children from lower SES is only in part genetic. Improvements in the
educational system might in fact be effective in reducing the difference. After controlling
for SES, there is some evidence that even minimal increase in parent involvement plays a
positive role on the mastery of basic skills (Gorard and Huat See, 2008).
Research referring to the USA (Lara-Cinisomo et al., 2004) shows that the main
factors associated with the educational achievement of children are not race, ethnicity, or
immigrant status, but, to a much greater extent, the socioeconomic environment. These
factors include parental education, neighbourhood poverty, parental occupational status,
and family income. An ample review by the Royal Society (2008) stresses the strong link
between SES and attainment in reading, mathematics and science among students between
5 and 11 years of age. Students from higher SES backgrounds obtain, on average, higher
marks and examination grades, whatever the subject (Hogrebe et al., 2006).
3.3. Differences among individuals and nations
The hypothesis that genes are a causal factor for cognitive differences is still highly
controversial whenever we look at ethnic and national differences (Nisbett, 1998;
Sternberg, 2005; Sternberg, Grigorenko and Kidd, 2005). At the moment, there is no
evidence of specific genes that account for intelligence and that differ around the world
(Cooper 2005; Wicherts and Wilhelm, 2007; Rindermann and Ceci, 2009). As clearly
pointed out by Spinath (2007: 752), the well-documented and highly consistent result that
genes contribute to individual differences in intelligence cannot be used as evidence for a
genetic influence on differences among groups in intelligence. While individual differences
in cognitive ability largely depend on genetic factors, the role of environmental factors in
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explaining international differences in cognitive ability is likely to play a much more
relevant role than for individuals (Meisenberg, 2003; Rindermann and Ceci, 2009).
In a study on the black-white IQ gap based on nine standardized samples relating to
four major tests, Dickens and Flynn (2006) have shown that blacks have reduced the gap,
gaining 5 or 6 IQ points on non-Hispanic whites between 1972 and 2002. As stated by
Dickens and Flynn (2006: 917): “Neither changes in the ancestry of those classified as
black nor changes in those who identify as black can explain more than a small fraction of
this gain.”
The crucial role of environmental conditions on average cognitive levels of
populations is confirmed by the massive rise in IQ that took place in many countries during
the 20th century, known as the Flynn effect: the increase in the standard of living, that is in
health, nutrition, education, mass media have all been proposed as determinants of IQ gains
(Meisenberg, 2003). The estimates of national IQ by Lynn and Vahnanen (2002) highly
correlate with all the variables proposed as causes of the Flynn effect (Flynn, 1999):
secondary enrolment ratio (0.78), pupil-teacher ratio (-0.72), the number of PCs per 1000
persons (0.66), fertility rate (-0.86) and urbanisation (0.67) (Wicherts and Wilhelm, 2007;
Wicherts et al., 2010). The result is a national g-factor more similar to the socio-economic
developmental status of a country than g at the individual level (Brunner and Martin, 2007).
The international differences in cognitive competence can be explained in a large part by
aspects of the educational systems of the respective countries, including the amount of
pre-school education, student discipline, quantity of education, attendance at additional
schools, early tracking, the use of centralized exams and high stakes tests, and adult
educational attainment (Rinderman and Ceci, 2009). Since these differences can be
reduced by reforming educational policy, there are implications not only for closing
international gaps in educational achievement, but also for narrowing gaps in wealth,
health, and democracy.
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4. Conclusions
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 casual 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.
18
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
19
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.
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26
APPENDIX
Table 1. Database for IQs and related variables (North: rows 1-10; South: rows 11-16)
1
2
3
4
5
6
7
8
9
10
Maths
(II cl.)
Maths
(V cl)
GDP per
capita
1891
GDP per
capita
1911
Maths
PISA
Mean
Education
IQ
Stature
1855
Stature
1910
Stature
1927
1
Piemonte
55.3
59.3
449.2
672.1
492
502
100
162.1
167.0
168.9
2
Lombardia
55.4
58.4
478.5
698.7
487
492
100
162.5
166.2
168.1
3
Veneto
55.5
60.4
374.6
484.8
510
515
101
164.8
167.1
169
4
Friuli Ven. G.
55.1
59.9
375.0
485.0
513
522
103
165.3
167.4
171.7
5
Trentino A.A.
52.4
55.5
375.0
485.0
508
512
101
169.2
6
Liguria
53.7
57.0
529.7
849.9
473
481
97
163.2
167.7
169.7
7
Emilia
55.2
58.5
464.5
619.5
494
500
100
163.4
166.6
169.2
8
Toscana
54.5
59.8
445.1
581.8
163.7
166.2
169.8
9
Umbria
56.2
59.8
513.8
593.7
161.9
164.6
167.2
10
Lazio
53.3
54.7
463.4
623.1
161.8
164.6
167.6
11
Abruzzi-Basilicata
55.6
56.1
342.7
416.6
443
447
92
159.6
162.8
164.2
12
Campania
56.0
57.2
487.5
612.5
436
439
90
160.2
162.9
164.9
13
Puglia
56.7
57.3
419.8
529.4
435
441
91
159.7
163.1
164.3
14
Calabria
57.4
57.4
316.6
418.6
158.3
162.2
163.3
15
Sicilia
50.8
50.4
435.2
520.1
423
427
90
160.2
163.3
164.7
16
Sardegna
53.2
51.6
431.0
537.6
429
438
89
158.5
160.6
162.1
11
12
13
14
15
16
17
18
19
20
Stature
1980
GDP per
capita
1970
GDP per
capita
2003
infant
mortality
1955-57
Infant
mortality
1990-02
Literacy
1880
Years
education
1951
Years
education
1971
Years
education
2001
Latitude
1
Piemonte
175.3
10,964
20,519
3.86
67.8
5.1
5.5
8.6
45.0
2
Lombardia
175.2
11,693
22,639
45.4
3.61
63
5.2
45.0
3
Veneto
177.0
9,223
20,338
36.7
3.17
4.6
5.3
8.8
45.5
4
Friuli Ven. G.
178.0
8,985
20,750
38.3
2.5
45.9
5.2
5.7
9.0
46.0
5
Trentino A.A.
177.1
10,930
23,079
44.9
3.47
45.9
5.1
5.7
8.9
46.0
6
Liguria
175.1
9,517
20,000
40.8
4.05
55.5
5.1
5.9
9.0
44.5
7
Emilia
175.4
10,058
22,439
36.2
3.73
52.2
4.6
5.2
8.7
44.5
8
Toscana
175.8
10,022
19,666
35.2
3.24
38.1
4.4
5.2
8.6
43.5
9
Umbria
175.8
7,815
17,070
39.8
3.76
28.6
4.1
4.9
8.7
43.0
10
Lazio
175.5
10,317
20,207
41.8
4.8
5.8
9.4
41.5
11
Abruzzi-Basilicata
174.0
6,814
15,480
68.1
4.56
18.1
3.8
4.6
8.5
41.0
12
Campania
173.1
6,481
11,862
62.2
5.21
24.6
3.6
4.7
8.2
40.5
13
Puglia
173.3
6,313
12,030
70.4
5.88
20
3.4
4.5
8.0
40.0
14
Calabria
172.4
6,128
11,595
117.5
5.54
14.6
3.5
4.5
8.0
39.0
15
Sicilia
172.7
6,525
12,488
57.0
6.62
19.1
3.5
4.5
8.0
37.9
16
Sardegna
171.6
8,054
13,722
53.6
4.1
19.1
3.4
4.6
8.2
40.0
27
Table 2. Descriptive statistics for Invalsi data on math scores
Variable
Mean
Median
Minimum
Maximum
Std.
Dev.
C.V.
Math_II_class
55.01
55.35
50.80
57.40
1.63
0.03
Math_V_class
57.22
57.25
50.40
60.70
2.73
0.05
Table 3. Correlation matrix for variables
Maths (II
clas)
Maths (V cl)
Maths PISA
Mean Educa-
tion
IQ
Stature
1855
Stature
910
Stature
1927
Stature
1980
GDP pc
1970
GDP pc
2003
Infant mortal-
ity 1955-7
Infant mortal-
ity 1990-02
Literacy
1880
Years educ
1951
Years educ
1971
Years educ
2001
Latitude
Maths (II clas)
1.00
Maths (V cl)
0.70
1.00
Maths PISA
0.16
0.72
1.00
Mean Education
0.16
0.72
1.00
1.00
IQ
0.17
0.72
0.99
0.99
1.00
Stature 1855
-0.05
0.64
0.94
0.93
0.92
1.00
Stature 1910
0.01
0.66
0.90
0.89
0.90
0.93
1.00
Stature 1927
-0.09
0.61
0.92
0.92
0.93
0.96
0.96
1.00
Stature 1980
-0.02
0.63
0.95
0.94
0.93
0.94
0.87
0.92
1.00
GDP pc 1970
-0.25
0.31
0.80
0.81
0.84
0.67
0.73
0.74
0.66
1.00
GDPpc 2003
-0.18
0.44
0.92
0.92
0.94
0.84
0.86
0.86
0.84
0.93
1.00
Inf. Mort. 1955-7
0.39
-0.26
-0.83
-0.85
-0.84
-0.78
-0.67
-0.72
-0.66
-0.68
-0.72
1.00
Inf..Mort. 1990-02
-0.06
-0.61
-0.86
-0.87
-0.86
-0.77
-0.67
-0.76
-0.81
-0.75
-0.83
0.67
1.00
Literacy 1880
-0.10
0.46
0.83
0.84
0.86
0.75
0.87
0.81
0.67
0.90
0.88
-0.66
-0.64
1.00
Years educ 1951
-0.15
0.46
0.90
0.90
0.93
0.82
0.90
0.89
0.83
0.89
0.94
-0.63
-0.76
0.92
1.00
Years educ 1971
-0.27
0.33
0.86
0.87
0.87
0.78
0.83
0.86
0.79
0.86
0.88
-0.64
-0.75
0.86
0.96
1.00
Years educ 2001
-0.21
0.32
0.88
0.88
0.89
0.72
0.69
0.76
0.80
0.77
0.85
-0.72
-0.87
0.69
0.86
0.91
1.00
Latitude
0.04
0.65
0.97
0.97
0.98
0.89
0.90
0.89
0.89
0.81
0.91
-0.70
-0.89
0.85
0.90
0.81
0.73
1.00
28
Table 4. Correlation matrix for variables
GDP pc 1891
GDP pc 1911
Mean Educa-
tion
IQ
Stature
1855
Stature
910
Stature
1927
Stature
1980
GDP pc
1970
GDP pc
2003
Infant mortal-
ity 1955-7
Infant mortal-
ity 1990-02
Literacy
1880
Years educ
1951
Years educ
1971
Years educ
2001
Latitude
GDP pc 1891
1.00
GDP pc 1911
0.88
1.00
Mean Education
-0.17
0.11
1.00
IQ
-0.13
0.15
0.99
1.00
Stature 1855
0.23
0.33
0.93
0.92
1.00
Stature 1910
0.29
0.51
0.89
0.90
0.93
1.00
Stature 1927
0.22
0.38
0.92
0.93
0.96
0.96
1.00
Stature 1980
0.01
0.10
0.94
0.93
0.94
0.87
0.92
1.00
GDP pc 1970
0.29
0.49
0.81
0.84
0.67
0.73
0.74
0.66
1.00
GDP pc 2003
0.19
0.37
0.92
0.94
0.84
0.86
0.86
0.84
0.93
1.00
Inf. Mort. 1955-7
-0.52
-0.46
-0.85
-0.84
-0.78
-0.67
-0.72
-0.66
-0.68
-0.72
1.00
Inf..Mort. 1990-02
-0.06
-0.17
-0.87
-0.86
-0.77
-0.67
-0.76
-0.81
-0.75
-0.83
0.67
1.00
Literacy 1880
0.41
0.67
0.84
0.86
0.75
0.87
0.81
0.67
0.90
0.88
-0.66
-0.64
1.00
Years educ 1951
0.21
0.47
0.90
0.93
0.82
0.90
0.89
0.83
0.89
0.94
-0.63
-0.76
0.92
1.00
Years educ 1971
0.25
0.50
0.87
0.87
0.78
0.83
0.86
0.79
0.86
0.88
-0.64
-0.75
0.86
0.96
1.00
Years educ 2001
0.23
0.37
0.88
0.89
0.72
0.69
0.76
0.80
0.77
0.85
-0.72
-0.87
0.69
0.86
0.91
1.00
Latitude
0.13
0.32
0.97
0.98
0.89
0.90
0.89
0.89
0.81
0.91
-0.70
-0.89
0.85
0.90
0.81
0.73
1.00
... INVALSI, an Italian institution, uses larger samples which additionally include children. The northern intellectual advantage is less dramatic in INVALSI scores than in PISA scores (Cornoldi et al., 2010;Cornoldi, Giofré & Martini, 2013) or is not seen at all in the first years of school (Daniele & Malanima, 2011;Robinson, Saggino & Tommasi, 2011). On the other hand, significant latitude-IQ-GDP correlations have emerged in the Raven standardization in Italy (Cornoldi et al., 2010) -objected by D' Amico et al. (2012) -and in other tests (e.g., Piffer & Lynn, 2014). ...
... The whole set of results in the literature is explainable by UV photons impairing socio-economic development (measured as a socio-economic latent variable, SELV), which in turn affects CCA. Whereas the radiation → SELV causal path may take a number of generations to materialize as culture, the greater cognitive impact of latitude observed among adolescents than children (Studies 1 and 2; Daniele & Malanima, 2011;Robinson, Saggino & Tommasi, 2011) suggests a cumulative process of environmental cognitive shaping at the individual level. ...
Article
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Lynn’s (2010) attribution of decreasing north-to-south PISA scores and GDP in Italy to inherited intelligence caused debate, but cognitive-capitalism’s tenet that regional/national intelligence, inherited or not, determines provincial/country wealth remains unchallenged. We introduce a new theory into the debate and test a UV radiation → intelligence → socioeconomic latent variable (SELV) model vis-à-vis a radiation → SELV → intelligence one. Only the latter is found well-adjusted in Italy, more so when intelligence is assessed in adolescents than children. Since hair and eye color vary with latitude in Italy and UV radiation could be a proxy for ancestry, the models are retested among White students in the USA. Similar results observed suggest that, in both countries, increased UV radiation impairs socio-economic development, perhaps by reducing industriousness through oxidative stress. The ensuing less-developed social environments exert negative influences on individuals’ cognition. Yet, ancestry appears to add latitudinal socioeconomic variance in Italy. A third study in Brazil, in turn, shows that cognitive effects of UV radiation through SELV are clearly distinguishable from the cognitive effects of race. The results suggest that the postulate that intelligence causes wealth needs revision. Key Words: UV radiation; Intelligence; Socioeconomic latent variable; Italy; USA; Brazil
... For this quantitative review, studies were included if they: (1) provided non-redundant information; (2) measured cognitive ability with intelligence or academic achievement tests (but not with cognitive proxies such as literacy, as in Grigoriev, Lapteva, & Lynn, 2016); (3) provided correlations between relatively contemporaneous measures of cognitive ability and socioeconomic outcomes (but not between cognitive ability and outcomes from many decades apart, as in Daniele & Malanima, 2011); (4) provided zero-order correlation coefficients or a table from which these could be computed; (5) were published in peerreviewed journals. Based on these inclusion criteria, 46 studies were identified covering 22 countries. ...
... This thesis was criticized by several Italian researchers who argued that PISA scores are a measure of educational attainment rather than of intelligence and proposed economic, educational, and social explanations for the north-south differences in IQs and PISA scores (Beraldo, 2010;Cornoldi, Belacchi, Giofre, Martini, & Tressoldi, 2010;Daniele & Malanima, 2011;Felice & Giugliano, 2011;D'Amico, Cardaci, Di Nuovo, & Naglieri, 2012;Cornoldi, Giofrè, & Martini, 2013;Daniele, 2013;and Daniele, 2015). ...
Article
Differences in intelligence have previously been found to be related to a wide range of inter-individual and international social outcomes. There is evidence indicating that intelligence differences are also related to different regional outcomes within nations. A quantitative and narrative review is provided for twenty-two countries (number of regions in parentheses): Argentina (24 to 437), Brazil (27 to 31), British Isles (12 to 392), to 79), Spain (15 to 48), Switzerland (47), Turkey (12), the USA (30 to 3100), and Vietnam (61). Between regions, intelligence is significantly associated with a wide range of economic, social, and demographic phenomena, including income (r unweighted = .56), educational attainment (r unweighted = .59), health (r unweighted = .49), general socioeconomic status (r unweighted = .55), and negatively with fertility (r unweighted = −.51) and crime (r unweighted = −.20). Proposed causal models for these differences are noted. It is concluded that regional differences in intelligence within nations warrant further focus; methodological concerns that need to be addressed in future research are detailed.
... Lynn's thesis on north-south disparities in Italy raised much criticism. It has been observed, in particular, that PISA tests measure scholastic achievements, not general intelligence, and, furthermore, that the north-south disparities in achievements and in socioeconomic development are due to historical and economic factors (Beraldo, 2010;Cornoldi et al. 2010Cornoldi et al. , 2013Felice and Giugliano, 2011;Daniele and Malanima, 2011;D'Amico et al. 2012;Daniele, 2015). ...
Article
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The relationship between PISA 2012 maths test scores and relative poverty was tested in a sample of 35 Italian and Spanish regions, together with a larger sample that included Australian, Belgian, and Canadian regions. The correlation between mean scores in mathematics, adjusted for students' socioeconomic and cultural backgrounds, and poverty rates is ‐−0.84 for the Italian and Spanish sample, and −0.68 for the complete sample. In the regressions, the effect of relative poverty on mean scores in mathematics is highly significant (p < 0.01), robust to different specifications, and independent from students' backgrounds and regional development levels. It is proposed that disparities in average scores in mathematics across regions depend on the shares of low-performing students which, in turn, depend on the degree of relative poverty within regions. The implications for the thesis according to which, in Italy and Spain, regional disparities in educational achievements reflect genetic differences in the IQ of populations are discussed.
... We still have to examine whether UV-induced behavioral changes are more plausible than the alternatives as explanation for differences in economic development between countries and provinces. The two alternatives are theories attributing these differences to genetics (Lynn, 2010) or to history (Daniele & Malanima, 2011). ...
Article
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In this comment on the target article by Federico Leon and Mayra Antonelli-Ponti, I examine whether there are any known mechanisms through which effects of UV radiation on the skin can possibly induce changes in the brain. The conclusion is that several possible mechanisms exist. However, this does not imply that UV radiation does indeed induce important effects on human behavior, and there is evidence contradicting the importance of such effects for society-level outcomes. First, I want to thank the authors for presenting their UV radiation theory for critical comments. The evidence presented in support of the theory consists mainly of ecological observations about relationships between intensity of UV radiation and socioeconomic development. The primary effect appears to be not on one or another aspect of cognition, but on non-cognitive traits that impair the acquisition of cognitive skills indirectly. Because UV radiation does not penetrate beyond the skin and behavior is organized by the brain, any effect of UV radiation on human behavior requires a mechanism whereby UV-induced changes in the skin are transmitted to the brain. Therefore I will first examine some evidence related to effects of UV radiation on behavior, before assessing the plausibility of the UV hypothesis in a wider context.
... Consistent with the theory of racial differences in intelligence, he argued that the comparatively lower 'IQ scores' of southern Italians are due to the genetic legacy of Phoenicians and Arabs that, in different epochs, colonized some areas of the South. As was easily predictable, Lynn's paper raised a debate, and his thesis was criticized on historical, economic and methodological grounds (Beraldo, 2010;Cornoldi et al., 2010;D'Amico et al., 2012;Daniele & Malanima, 2011b;Daniele, 2015). ...
Article
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Contrary to Leon & Antonelli-Ponti's claim that regional socio-economic and cognitive differences between Italian provinces are best explained by differences in UV radiation, it is argued that (1) these differences are of rather recent origin, dating to the period of industrialization in the 19th and 20th centuries; and (2) regional differences in Europe today are better explained by distance from the continent's economic center of gravity in North-Western Europe. Neither UV radiation theory nor Lynn's genetic theory are required to explain economic differentials in modern Europe. © 2018 Ulster Institute for Social Research. All rights reserved.
... In the past, some authors argue that differential in human capital endowment and intelligence can be called for as one factor (see the discussion in Refs. [18,17]), while others pointed at highlighting resources unevenly distributed (see Ref. [12]), other again discussed the mobility of teachers across the NortheSouth directory (see Ref. [6]). Whatever the causes, our paper discusses one consequence for the geographical gap: not only the levels of (measured) cognitive skills are higher for students in the North than in the South, all else equal; but also the role of schools in influencing test scores is stronger in the South, so adding to the inequality of opportunities for those students who are enrolled in schools where the impact on achievement is negative. ...
Article
This paper assesses the differences in educational attainments between students across classes and schools they are grouped by, in the context of Italian educational system. The purpose is to identify a relationship between pupils’ reading test scores and students’ characteristics, stratifying for classes, schools and geographical areas. The dataset contains detailed information about more than 500,000 students at the first year of junior secondary school in the year 2012/2013. By means of multilevel linear models, it is possible to estimate statistically significant school and class effects, after adjusting for pupil’s characteristics, including prior achievement. The results show that school and class effects are very heterogeneous across macro-areas (Northern, Central and Southern Italy), and that there are substantial discrepancies between and within schools; overall, class effects on achievement tend to be larger than school ones.
Article
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We relate students’ math scores in the OECD-PISA test to school characteristics. The average math score for Italian students has been increasing in 2009. The determinants of this growth are analyzed by the Oaxaca–Blinder decomposition, that is particularly useful in comparing groups. The progress in educational attainments shows a different composition between northern and southern schools. In the North-Center regions, improvements are explained by school endowments, while in the South they are also driven by external factors that are not explained by the estimated model and are linked to improvements in students' attitude to education leading to a more favorable disciplinary climate. The regional gap decreases but does not disappear.
Article
This paper analyses data on average IQ and four measures of political attitudes at both the regional level (n = 11) and the local authority level in Britain (n = 372). At the regional level, average IQ is positively associated with right-wing economic attitudes and trust in experts, but is not significantly associated with liberal social attitudes or intention to vote Remain in the EU referendum. At the local authority level, average IQ is positively associated with all four measures of political attitudes, although the associations with right-wing economic attitudes and trust in experts are stronger than the associations with liberal social attitudes and intention to vote Remain in the EU referendum. In multivariate models, average SES is a better and more robust predictor of political attitudes than average IQ.
Article
The recent availability of more accurate estimates of regional gdp, of social indicators (human capital, life expectancy, the human development index [hdi], heights, inequality, and social capital), and of other indices (such as market potential) has helped to advance the study of the growth patterns within Italian regions from (approximately) unification to the present day. This up-to-date information provides the basis for a new explanation of Italy's industrial expansion and economic growth: The North-South socio-institutional divide that existed in Italy before unification in some respects grew stronger after unification, never to be bridged. This geographical division ultimately carried differences in human and social capital, governmental policies, and various institutions that exerted considerable influence on the regional structure of Italy's economic growth. © 2018 by the Massachusetts Institute of Technology and The Journal of Interdisciplinary History, Inc.
Article
Cross-regional correlations between average IQ and socio-economic development have been reported for many different countries. This paper analyses data on average IQ and a range of socio-economic variables at the local authority level in the UK. Local authorities are administrative bodies in local government; there are over 400 in the UK, and they contain anywhere from tens of thousands to more than a million people. The paper finds that local authority IQ is positively related to indicators of health, socio-economic status and tertiary industrial activity; and is negatively related to indicators of disability, unemployment and single parenthood. A general socio-economic factor is correlated with local authority IQ at r = .56. This correlation increases to r = .65 when correcting for measurement error in the estimates of IQ.
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Full-text available
The question of cognitive differences between human populations is one of the most contentious issues in the study of human diversity. After reviewing the worldwide patterns of cognitive test performance, this article evaluates alternative causal hypotheses and evolutionary mechanisms. Racial affiliation and latitude correlate with IQ test performance, as does economic development. Religion, a history of colonialism, and a history of Communist rule are important in some cases. This article proposes mechanisms of gene-culture co-evolution that can explain the worldwide patterns. The genetic component of these mechanisms is likely to become testable with further advances in molecular genetics.
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The target paper identifies a common factor underlying measures of intelligence and student achievement on the cross-national level. Given the level of analysis applied, however, this factor cannot be interpreted as general cognitive ability (g). Rather it is an indicator of a nation's prosperity. g operates at the individual level and not at the cross-national level. Copyright (C) 2007 John Wiley & Sons, Ltd.
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Jencks' (1972) classical study Inequality reported a correlation of 0.310 between IQ and income for men in the United States. The present study examines whether this result can be replicated in Britain. Data are reported for a national sample whose intelligence was obtained at the age of 8 years and whose income was obtained at the age 43 years. The correlations between IQ and income were 0.368 for men (n=1280) and 0.317 for women (n=1085).
Conference Paper
Humane-egalitarian ideals, whose aims are group justice and reducing environmental inequality and privilege, must be rested against reality: as revealed by psychology and other social sciences. Four issues are addressed: the equation between IQ and intelligence, whether group potential is determined by a group's mean Ie, whether the Black-White re gap is genetic, and the meritocratic thesis that genes for Ie,will become highly correlated with class. Massive Ie gains ol er time test the IQ-intelligence equation, reveal groups who achieve far beyond their mean les, and falsify prominent arguments for a genetic racial le gap. Class re trends suggest America is not evolving toward a meritocracy, brit ct core refutation of that thesis is needed and supplied. Finally, the viability of humane ideals is assessed against a worst-case scenario.