Unterschiede in der Verteilung der Intelligenz bei Männern und Frauen

Terminator macht auf einige Studien zur Verteilung der Intelligenz innerhalb der Geschlechter aufmerksam:

Brother–sister differences in the g factor in intelligence: Analysis of full, opposite-sex siblings from the NLSY1979 Original Research Article

Intelligence, Volume 35, Issue 5, September-October 2007, Pages 451-456

Ian J. Deary, Paul Irwing, Geoff Der, Timothy C. Bates


There is scientific and popular dispute about whether there are sex differences in cognitive abilities and whether they are relevant to the proportions of men and women who attain high-level achievements, such as Nobel Prizes. A recent meta-analysis (Lynn, R., and Irwing, P. (2004). Sex differences on the progressive matrices: a meta-analysis. Intelligence, 32, 481–498.), which suggested that males have higher mean scores on the general factor in intelligence (g), proved especially contentious. Here we use a novel design, comparing 1292 pairs of opposite-sex siblings who participated in the US National Longitudinal Survey of Youth 1979 (NLSY1979). The mental test applied was the Armed Services Vocational Aptitude Battery (ASVAB), from which the briefer Armed Forces Qualification Test (AFQT) scores can also be derived. Males have only a marginal advantage in mean levels of g (less than 7% of a standard deviation) from the ASVAB and AFQT, but substantially greater variance. Among the top 2% AFQT scores, there were almost twice as many males as females. These differences could provide a partial basis for sex differences in intellectual eminence.

Sex-related differences in general intelligence g, brain size, and social status Original Research Article

Personality and Individual Differences, Volume 39, Issue 3, August 2005, Pages 497-509

Helmuth Nyborg


The question of a sex difference in intelligence has long divided the experts. IQ researchers sum standardized subtest scores to calculate intelligence in general, and find that males outscore females by about 3.8 points, whereas factor analysts derive the g factor scores from intertest-correlations and find no consistent sex differences in general intelligence. The latter finding is puzzling, as males have larger average brains than females, and brain size correlates .30–.45 with g (and IQ). Males thus “ought” to score a higher g than females.

The present study addressed this paradox by testing four hypotheses: (1) Inadequate analyses explain why researchers get inconsistent results, (2) The proper method will identify a male g lead, (3) The larger male brain “explains” the male g lead, (4) The higher male g average and wider distribution transform into an exponentially increased male–female ratio at the high end of the g distribution, and this largely explains male dominance in society.

All four hypotheses obtained support and explain in part why relatively few males dominate the upper strata in all known societies. The confirmation of hypothesis 3 suggests that the brain size—intelligence–dominance link may be partly biological.

Testing the developmental theory of sex differences in intelligence on 12–18 year olds Original Research Article

Personality and Individual Differences, Volume 36, Issue 1, January 2004, Pages 75-82

Roberto Colom, Richard Lynn


The consensus view states that there are no sex differences in intelligence. However, Lynn (1994, 1999) has formulated a developmental theory of sex differences in intelligence that challenges that view. The theory states that boys and girls mature at different rates such that the growth of girls accelerates at the age of about 9 years and remains in advance of boys until 14–15 years. At 15–16 years the growth of girls decelerates relative to boys. As boys continue to grow from this age their height and their mean IQs increase relative to those of girls. This paper presents new evidence for the theory from the Spanish standardization sample of the fifth edition of the DAT. 1027 boys and 924 girls between 12 and 18 years were tested. The general trend shows that girls do better at the younger ages and their performance declines relative to boys among older age groups, which supports the developmental theory. The sex difference for the DAT as a whole for 18 year olds is a 4.3 IQ advantage for boys, very close to the advantage that can be predicted from their larger brain size (4.4 IQ points). The profile of sex differences in abilities among the Spanish sample is closely similar to that in the United States and Britain, which is testimony to the robustness of the difference in these different cultures.

Sex differences in brain size, stature and intelligence in children and adolescents: some evidence from Estonia Original Research Article

Personality and Individual Differences, Volume 29, Issue 3, 1 September 2000, Pages 555-560

Richard Lynn, Juri Allik, Olev Must


Sex differences in brain size and stature decrease from the age of 7 through 13–14 years and increase from the age of 15 through 18 years in Estonia, as they do in the United States. Sex differences in intelligence show a somewhat similar decrease and increase although they do not move precisely in synchrony with the morphological trends. The results are interpreted as suggesting that sex differences in maturation determine the magnitude of sex differences in physical and mental development during childhood and adolescence.

Do sex differences in a faceted model of fluid and crystallized intelligence depend on the method applied? Original Research Article

Intelligence, Volume 38, Issue 1, January-February 2010, Pages 101-110

Ricarda Steinmayr, André Beauducel, Birgit Spinath


Recently, different methodological approaches have been discussed as an explanation for inconsistencies in studies investigating sex differences in different intelligences. The present study investigates sex differences in manifest sum scores, factor score estimates, and latent verbal, numerical, figural intelligence, as well as fluid and crystallized intelligence as measured by the German Intelligence-Structure-Test 2000-R (IST 2000-R; Liepmann, Beauducel, Brocke, & Amthauer, 2007). The not population-representative sample consisted of 977 German 11th and 12th graders enrolled in a “Gymnasium” (551 female; mean age: M = 16.70; SD = 0.65) who completed the IST 2000-R. Sex differences in fluid and crystallized intelligence were not influenced by the method applied with men performing better than women. However, extent and direction of sex differences in verbal, numerical, and figural intelligence differed by the method applied. Whereas there was a male advantage in all three factors measured as manifest sum scores, women performed better in verbal intelligence as measured by factor scores or as latent variables. Effect sizes of sex differences in numerical and figural intelligence were also greatly reduced when applying the latter two methods. Results are discussed with regard to their theoretical and practical implications.

Factor structure and sex differences on the Wechsler Preschool and Primary Scale of Intelligence in China, Japan and United States Original Research Article

Personality and Individual Differences, Volume 50, Issue 8, June 2011, Pages 1222-1226

Jianghong Liu, Richard Lynn


This study presents data on the factor structure of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) and sex and cultural differences in WPPSI test scores among 5- and 6-year-olds from China, Japan, and the United States. Results show the presence of a verbal and nonverbal factor structure across all three countries. Sex differences on the 10 subtests were generally consistent, with a male advantage on a subtest of spatial abilities (Mazes). Males in the Chinese sample obtained significantly higher Full Scale IQ scores than females and had lower variability in their test scores. These observations were not present in the Japan and United States samples. Mean Full Scale IQ score in the Chinese sample was 104.1, representing a 4-point increase from 1988 to 2004.

A longitudinal study of sex differences in intelligence at ages 7, 11 and 16 years Original Research Article

Personality and Individual Differences, Volume 51, Issue 3, August 2011, Pages 321-324

Richard Lynn, Satoshi Kanazawa


This paper presents the results of a longitudinal study of sex differences in intelligence as a test of Lynn’s (1994) hypothesis that from the age of 16 years males develop higher average intelligence than females. The results show that at the ages of 7 and 11 years girls have an IQ advantage of approximately 1 IQ point, but at the age of 16 years this changes in the same boys and girls to an IQ advantage of 1.8 IQ points for boys.

Intelligence and neural efficiency: Further evidence of the influence of task content and sex on the brain–IQ relationship Original Research Article

Cognitive Brain Research, Volume 25, Issue 1, September 2005, Pages 217-225

Aljoscha C. Neubauer, Roland H. Grabner, Andreas Fink, Christa Neuper


In the field of physiological study of human intelligence, strong evidence of a more efficient operation (i.e., less activation) of the brain in brighter individuals (the neural efficiency hypothesis) can be found. Most studies in this field have used single, homogeneous tasks and have not examined sex differences. In analyzing the extent of Event-related Desynchronization (ERD) in the EEG during the performance of a verbal and a visuo-spatial task, we recently found that males and females display neural efficiency primarily in the domain where they usually perform better (i.e., verbal in females and spatial in males; cf. A.C. Neubauer, A. Fink, D.G. Schrausser, Intelligence and neural efficiency: the influence of task content and sex on brain–IQ relationship. Intelligence, 30 (2002) 515–536). However, this interpretation was complicated by differences in the complexity of the two tasks. By using a verbal (semantic) and a spatial (rotation) task of comparable complexity in this research, we sought to replicate and extend our earlier findings by additionally considering the individual differences in intelligence structure and the topographical distribution over the cortex. Findings were similar to the previous study: Females (n = 35) display neural efficiency (i.e., less brain activation in brighter individuals) primarily during the verbal task, males (n = 31) in the spatial task. However, the strength of this brain activation–IQ relationship varies with the intelligence factor: In males, the highest correlations were observed for spatial IQ, in females for verbal IQ. Furthermore, the sexes displayed topographical differences of neural efficiency patterns.

Sex differences in mental abilities: g masks the dimensions on which they lie Original Research Article

Intelligence, Volume 35, Issue 1, January-February 2007, Pages 23-39

Wendy Johnson, Thomas J. Bouchard Jr.


Empirical data suggest that there is at most a very small sex difference in general mental ability, but men clearly perform better on visuospatial tasks while women clearly perform better on tests of verbal usage and perceptual speed. In this study, we integrated these overall findings with predictions based on the Verbal–Perceptual–Rotation (VPR) model ([Johnson, W., and Bouchard, T. J. (2005a). Constructive replication of the visual–perceptual–image rotation (VPR) model in Thurstone’s (1941) battery of 60 tests of mental ability. Intelligence, 33, 417–430.; Johnson, W., and Bouchard, T. J. (2005b). The structure of human intelligence: It’s verbal, perceptual, and image rotation (VPR), not fluid and crystallized. Intelligence, 33. 393–416.]) of the structure of mental abilities. We examined the structure of abilities after removing the effects of general intelligence, identifying three underlying dimensions termed rotation–verbal, focus–diffusion, and memory. Substantial sex differences appeared to lie along all three dimensions, with men more likely to be positioned towards the rotation and focus poles of those dimensions, and women displaying generally greater memory. At the level of specific ability tests, there were greater sex differences in residual than full test scores, providing evidence that general intelligence serves as an all-purpose problem solving ability that masks sex differences in more specialized abilities. The residual ability factors we identified showed strong genetic influences comparable to those for full abilities, indicating that the residual abilities have some basis in brain structure and function.

Sex, masculinity—feminity, and intelligence Original Research Article

Intelligence, Volume 1, Issue 2, April 1977, Pages 218-233

George S. Welsh, Donald H. Baucom


Masculine and feminine subgroups of males and females were selected from samples of high school and college students on the basis of composite scores from several M—F scales. They were compared on intelligence as measured by a verbal test, Terman’s Concept Mastery Test, and a nonverbal test, D-48. Results did not support previous findings of sex differences in intelligence but showed that masculine subgroups of both sexes scored higher of the nonverbal test.

Sex differences in mental rotation and spatial visualization ability: Can they be accounted for by differences in working memory capacity? Original Research Article

Intelligence, Volume 35, Issue 3, May-June 2007, Pages 211-223

Scott Barry Kaufman


Sex differences in spatial ability are well documented, but poorly understood. In order to see whether working memory is an important factor in these differences, 50 males and 50 females performed tests of three-dimensional mental rotation and spatial visualization, along with tests of spatial and verbal working memory. Substantial differences were found on all spatial ability and spatial working memory tests (that included both a spatial and verbal processing component). No significant differences were found in spatial short-term memory or verbal working memory. In addition, spatial working memory completely mediated the relationship between sex and spatial ability, but there was also a direct effect of sex on the unique variance in three-dimensional rotation ability, and this effect was not mediated by spatial working memory. Results are discussed in the context of research on working memory and intelligence in general, and sex differences in spatial ability more specifically.

Sex differences on the WISC-R in Mauritius Original Research Article

Intelligence, Volume 33, Issue 5, September-October 2005, Pages 527-533

Richard Lynn, Adrian Raine, Peter H. Venables, Sarnoff A. Mednick, Paul Irwing


Sex differences on the WISC-R (Wechsler Intelligence Scale for Children-Revised) are examined in a sample of 1258 11 year olds in Mauritius. Boys obtained a significantly higher Full Scale IQ by 5.8 IQ points. Boys obtained a higher Performance IQ by 6.5 IQ points and a higher Verbal IQ by 1.0 IQ points. On the subtests, girls obtained a significantly higher mean on Coding while boys obtained significantly higher means on Similarities, Picture Completion, Block Design, Object Assembly and Mazes. There was no significant sex difference on Digit Span. Two methods were adopted for determining whether boys had an advantage on Spearman’s g. First, calculated from the first principal component of a principal components analysis, boys had an advantage on Spearman’s g of 6.15 IQ points. Second, using the method of entering the sex difference on each of the subtests as point-biserial correlations, including these in the full matrix of subtest correlations for factor analysis and examining the factor loading of sex on g produced a correlation between sex and g of .224, the equivalent of a sex difference of 6.9 IQ points. Thus the sex difference on the Full Scale IQ was found to be a good approximate measure of the difference in g. The pattern of sex differences in Mauritius is compared with that in eight other countries and found to be generally similar, although the boys’ advantage is greater in Mauritius than elsewhere. The variance in boys is slightly greater than in girls, but is only significant for Block Design.

Intelligence, sex and psychomotor performance Original Research Article

Personality and Individual Differences, Volume 3, Issue 4, 1982, Pages 457-459

Jitendra Mohan, Meena Sehgal, Anuradha Bhandari


This experiment investigated the effect of intelligence and sex on two simple psychomotor performance tests—Backward Figure Writing (BFW) and Backward Alphabet Writing (BAW) in 180 high-school students (90 boys and 90 girls). Three levels of intelligence, high, medium and low were taken. Ss being first matched on Extraversion and Neuroticism. Each S worked for 5 min in pre-test period, rested for 1 min and again worked for 2 min in post-rest period. Results indicated that in pre- and post-rest BFW, increase in speed of response was a direct function of increase in intelligence. Similar results were obtained in pre-rest BAW. In post-rest BAW, however, highest performance scores were obtained by the group, average in intelligence, followed by high and low intelligence groups. Sex did not emerge as a significant determiner of performance in BFW. In BAW, means favoured boys in both pre- and post-rest conditions and the F-ratio for sex emerged significant in post-rest BAW only. None of the interactions emerged as significant. The comparison of effects in two independent variables indicated the task-specific nature of various psychomotor tasks.

Sex differences on the progressive matrices: A meta-analysis Original Research Article

Intelligence, Volume 32, Issue 5, September-October 2004, Pages 481-498

Richard Lynn, Paul Irwing


A meta-analysis is presented of 57 studies of sex differences in general population samples on the Standard and Advanced Progressive Matrices (SPM and APM, respectively). Results showed that there is no difference among children aged 6–14 years, but that males obtain higher means from the age of 15 through to old age. Among adults, the male advantage is 0.33d equivalent to 5 IQ points. These results disconfirm the frequent assertion than there are no sex differences on the progressive matrices and support a developmental theory that a male advantage appears from the age of 15 years. A meta-analysis of 15 studies of child samples on the Colored Progressive Matrices showed that among children aged 5–11 years boys have an advantage of 0.21d equivalent to 3.2 IQ points.

Sex differences on three factors identified in Raven’s Standard Progressive Matrices Original Research Article

Intelligence, Volume 32, Issue 4, July-August 2004, Pages 411-424

Richard Lynn, Jüri Allik, Paul Irwing


Raven’s Standard Progressive Matrices (SPM) was administered to a sample of 2735 12- to 18-year-olds in Estonia. Both a scree test and the consistent Akaike information criterion (CAIC) indicated the presence of three significant factors. Exploratory and confirmatory factor analysis showed the loadings of the items on the three factors, which were identified as the gestalt continuation found by van der Ven and Ellis [Pers. Individ. Differ. 29 (2000) 45], verbal–analytic reasoning and visuospatial ability. Further analysis of the three factors showed a higher order factor identifiable as g. Examination of age by sex differences showed that on all four factors girls performed better than boys at the age of 12, there was no sex difference at age 14, while boys performed better than girls at the age of 17, although not significantly on visuospatial ability.

Sex differences in intelligence and brain size: A paradox resolved Original Research Article

Personality and Individual Differences, Volume 17, Issue 2, August 1994, Pages 257-271

Richard Lynn


Males have larger brains than females, even when corrected for body size, and brain size is positively correlated with intelligence. This leads to the expectation that males should have higher average levels of intelligence than females. Yet the consensus view is that there is no sex difference in general intelligence. An examination of the literature shows that the consensus view is wrong. Among adults, males have slightly higher verbal and reasoning abilities than females and a more pronounced superiority on spatial abilities. If the three abilities are combined to form general intelligence, the mean for males is 4 IQ points higher than the mean for females. Among children up to the age of around 14 yr the sex differences are smaller because girls mature earlier than boys. The evolutionary selection pressures responsible for greater intelligence in males are discussed.

Sex differences in latent general and broad cognitive abilities for children and youth: Evidence from higher-order MG-MACS and MIMIC models Original Research Article

Intelligence, Volume 36, Issue 3, May-June 2008, Pages 236-260

Matthew R. Reynolds, Timothy Z. Keith, Kristen P. Ridley, Puja G. Patel


Sex differences in the latent general and broad abilities underlying the Kaufman Assessment Battery for Children—Second Edition (KABC-II) were investigated for children and youth ages 6 through 18. The data were split into different age groups to account for changes due to differential development. Multi-group higher-order analysis of mean and covariance structures (MG-MACS) and multiple indicator-multiple cause (MIMIC) models were used to analyze these data. Boys consistently demonstrated a significant mean advantage on the latent visual–spatial ability (Gv) factor. A significant mean advantage was also found for boys on the latent crystallized ability (Gc) factor at all ages except for 17 and 18. Girls scored higher on the latent, higher-order g factor, at all ages, although this difference was statistically significant at only two age levels. An additional test, however, did not reveal a significant Age × Sex interaction effect, suggesting only main effects of Sex on Gv, Gc, and g.

Sex differences on the Progressive Matrices are influenced by sex differences on spatial ability Original Research Article

Personality and Individual Differences, Volume 37, Issue 6, October 2004, Pages 1289-1293

Roberto Colom, Sergio Escorial, Irene Rebollo


The Progressive Matrices Test (PM) is considered an excellent measure of general intelligence or g. There are several studies showing that, on average, males score higher than females on the PM. However, some investigations have demonstrated that there are no sex differences in g. Why are there these contradictory findings? The visuo-spatial format of the PM could be favourable to the male performance, because (on average) males score higher than females on overall spatial ability. The present study administered the Advanced Progressive Matrices Test (APM) and the Spatial Rotation Test from the Primary Mental Abilities Battery (PMA) to a sample of 239 university undergraduates. Males outperformed females on both tests. However, the male advantage on the APM turned out to be non-significant when sex differences on spatial rotation were statistically controlled. It is suggested that sex differences on the PM could be a by-product of its visuo-spatial format.

In a Scottish standardisation sample of the Wechsler Adult Intelligence Scale-Revised, men have a mean IQ of 105.09 and women of 100.00. The higher average mean obtained by men is consistent with four other standardisation samples of the WAIS and WAIS-R.

Sex differential item functioning in the Raven’s Advanced Progressive Matrices: evidence for bias Original Research Article

Personality and Individual Differences, Volume 36, Issue 6, April 2004, Pages 1459-1470

Francisco J. Abad, Roberto Colom, Irene Rebollo, Sergio Escorial


There are no sex differences in general intelligence or g. The Progressive Matrices (PM) Test is one of the best estimates of g. Males outperform females in the PM Test. Colom and García-López (2002) demonstrated that the information content has a role in the estimates of sex differences in general intelligence. The PM test is based on abstract figures and males outperform females in spatial tests. The present study administered the Advanced Progressive Matrices Test (APM) to a sample of 1970 applicants to a private University (1069 males and 901 females). It is predicted that there are several items biased against female performance, by virtue of their visuo-spatial nature. A double methodology is used. First, confirmatory factor analysis techniques are used to contrast one and two factor solutions. Second, Differential Item Functioning (DIF) methods are used to investigate sex DIF in the APM. The results show that although there are several biased items, the male advantage still remains. However, the assumptions of the DIF analysis could help to explain the observed results.

Sex differences on the WISC-R in New Zealand Original Research Article

Personality and Individual Differences, Volume 39, Issue 1, July 2005, Pages 103-114

Richard Lynn, David M. Fergusson, L. John Horwood


Sex differences on the WISC-R were examined in a sample of 897 New Zealand children studied at ages 8 and 9 years. Boys scored significantly higher than girls on the subtests of information, vocabulary, block design and object assembly, while girls scored significantly higher on coding. Boys obtained slightly but not significantly higher scores on the verbal, performance and full scale IQs. The results were in general similar to the sex differences in the standardisation samples of the WISC-R in Scotland, the Netherlands and the United States.

Sex ratios in the most-selective elite US undergraduate colleges and universities are consistent with the hypothesis that modern educational systems increasingly select for conscientious personality compared with intelligence

Medical Hypotheses, Volume 73, Issue 2, August 2009, Pages 127-129

Bruce G. Charlton



The main predictors of examination results and educational achievement in modern societies are intelligence (IQ – or general factor ‘g’ intelligence) and the personality trait termed ‘Conscientiousness’ (C). I have previously argued that increased use of continuous assessment (e.g. course work rather than timed and supervised examinations) and increased duration of the educational process implies that modern educational systems have become increasingly selective for the personality trait of Conscientiousness and consequently less selective for IQ. I have tested this prediction (in a preliminary fashion) by looking at the sex ratios in the most selective elite US universities. My two main assumptions are: (1) that a greater proportion of individuals with very high intelligence are men than women, and (2) that women are more conscientious than men. To estimate the proportion of men and women expected at highly-selective schools, I performed demonstration calculations based on three plausible estimates of male and female IQ averages and standard deviations. The expected percentage of men at elite undergraduate colleges (selecting students with IQ above 130 – i.e. in the top 2% of the population) were 66%, 61% and 74%. When these estimates were compared with the sex ratios at 33 elite colleges and universities, only two technical institutes had more than 60% men. Elite US colleges and universities therefore seem to be selecting primarily on the basis of something other than IQ – probably conscientiousness. There is a ‘missing population’ of very high IQ men who are not being admitted to the most selective and prestigious undergraduate schools, probably because their high school educational qualifications and evaluations are too low. This analysis is therefore consistent with the hypothesis that modern educational systems tend to select more strongly for Conscientiousness than for IQ. The implication is that modern undergraduates at the most-selective US schools are not primarily an intelligence elite, as commonly assumed, but instead an elite for Conscientious personality.

Sex differences in g: An analysis of the US standardization sample of the WAIS-III Original Research Article

Personality and Individual Differences, In Press, Corrected Proof, Available online 31 May 2011

Paul Irwing


This study employed both hierarchical and Bi-factor multi-group confirmatory factor analysis with mean structures (MGCFA) to investigate the question of whether sex differences are present in the US standardization sample of the WAIS-III. The data consisted of age scaled scores from 2450 individuals aged from 16 to 89 years. The findings were more or less uniform across both analyses, showing a sex difference favoring men in g (0.19–0.22d), Information (0.40d), Arithmetic (0.37–0.39d) and Symbol Search (0.40–0.30d), and a sex difference favoring women in Processing Speed (0.72–1.30d).

Sex differences on elementary cognitive tasks despite no differences on the Wonderlic Personnel Test Original Research Article

Personality and Individual Differences, Volume 45, Issue 5, October 2008, Pages 429-431

Bryan J. Pesta, Sharon Bertsch, Peter J. Poznanski, William H. Bommer


Whether males and females differ in general mental ability (GMA) remains an open question. Complicating the issue is that standardized IQ tests are constructed to minimize sex differences. We propose a potential solution whereby GMA is measured via performance on elementary cognitive tasks (ECTs). ECTs assess basic information-processing ability, yet correlate moderately highly with GMA. Toward this end, we had male (n = 218) and female (n = 226) undergraduates complete the Wonderlic Personnel Test (WPT), and two ECTs: inspection time (IT) and reaction time (RT). The sex difference on the WPT was non-significant (d = .17), but small differences favoring males existed for IT (d = .34), RT (d = .26), the standard deviation of RT (d = .30), and an ECT factor score (d = .38). Unlike standardized IQ tests, ECTs may be a viable research tool to help clarify and illuminate the nature of sex differences on GMA.

Sex differences on the progressive matrices among adolescents: some data from Estonia Original Research Article

Personality and Individual Differences, Volume 36, Issue 6, April 2004, Pages 1249-1255

Richard Lynn, Juri Allik, Helle Pullmann, Kaia Laidra


It has long been asserted that there are no sex differences on the Progressive Matrices. Contrary to this position, it has been contended by Lynn (1994, 1998) that there is a small difference favoring females from the age of approximately 9–14 years, and a difference favouring males from the age of 16 onwards, reaching approximately 2.4 IQ points among adults. Data to test these two theories are reported from a standardization of the Progressive Matrices on a sample of 2689 12–18 year olds in Estonia. The results confirm the Lynn theory and show a female advantage of 3.8 IQ points among 12–15 year olds and a male advantage of 1.6 IQ points among 16–18 year olds. Boys had a significantly larger standard deviation than girls. The results provide further confirmation that in early adolescence girls outperform boys on abstract (non-verbal) reasoning ability but that in later adolescence boys outperform girls.

Sex differences on the progressive matrices among 15–16 year olds: some data from South Africa Original Research Article

Personality and Individual Differences, Volume 33, Issue 4, September 2002, Pages 669-673

Richard Lynn


It has been widely asserted that there is no sex difference in mean scores on the Progressive Matrices. This paper presents an alternative theory that a male advantage on the test begins to appear at the age of 15 years. This alternative theory is supported by data for the largest sample hitherto reported consisting of 3979 15–16 year olds in South Africa. In this sample males obtained a significantly higher mean equivalent to 2.35 IQ points among 15 year olds and to 4.65 IQ points among 16 year olds.

Personality and Individual Differences, Volume 36, Issue 4, March 2004, Pages 779-787

Richard Lynn, Eduardo Backhoff, Luis A. Contreras-Niño


Normative data for sex differences on the Standard Progressive Matrices are presented for a sample of nine-hundred and twenty 7–10 year olds in Mexico. Factor analysis of the test showed the presence of factors identifiable as g, reasoning ability and visualisation. There was no statistically significant difference between boys and girls on the test, on g, or on reasoning. There was, however, a significant advantage for boys on the visualisation factor. There was also a non-significant trend for the boys’ advantage on the test to decline over the 4 years and to turn into an advantage for girls at age 10. This is consistent with the faster maturation of girls from the age of about 10 through 15 years.

Sex differences on the Dutch WAIS-III Original Research Article

Intelligence, Volume 34, Issue 3, May-June 2006, Pages 273-289

Sophie van der Sluis, Danielle Posthuma, Conor V. Dolan, Eco J.C. de Geus, Roberto Colom, Dorret I. Boomsma


Summarizing, the present study showed that males and females do differ with respect to specific cognitive abilities, but that g cannot be viewed as the sour

Ich eröffne dazu mal einen eigenen Betrag zur Übersichtlichkeit der Disskussion.

Hormonelle, genetische und andere Faktoren für Geschlechterunterschiede

Weitere Studien, die verschiedene Faktoren für Geschlechterunterschiede untersuchen:

Both sexual orientation and sex-typical childhood behaviors, such as toy, playmate and activity preferences, show substantial sex differences, as well as substantial variability within each sex. In other species, behaviors that show sex differences are typically influenced by exposure to gonadal steroids, particularly testosterone and its metabolites, during early development (prenatally or neonatally). This article reviews the evidence regarding prenatal influences of gonadal steroids on human sexual orientation, as well as sex-typed childhood behaviors that predict subsequent sexual orientation. The evidence supports a role for prenatal testosterone exposure in the development of sex-typed interests in childhood, as well as in sexual orientation in later life, at least for some individuals. It appears, however, that other factors, in addition to hormones, play an important role in determining sexual orientation. These factors have not been well-characterized, but possibilities include direct genetic effects, and effects of maternal factors during pregnancy. Although a role for hormones during early development has been established, it also appears that there may be multiple pathways to a given sexual orientation outcome and some of these pathways may not involve hormones.

Research highlights

► Prenatal exposure to androgenic hormones influences human sexual orientation. ► Androgen dose predicts the likelihood of non-heterosexual orientation. ► Normal variability in testosterone prenatally predicts masculinity in childhood. ► Sexual orientation is predicted by masculinity/femininity of childhood behavior. ► Prenatal stress does not demasculinize boys, but may masculinize girls slightly.

Quelle: Prenatal endocrine influences on sexual orientation and on sexually differentiated childhood behavior

Die Studie passt zu den anderen Studien. Pränatales Testosteron beeinflusst die sexuelle Orientierung, dass Verhalten während der Kindheit etc. Da die Auswirkungen zu dem Testosteronspiegel im Mutterleib passen, sind sie mit der Gesellschaft nicht zu erklären.

Die Rolle der Gene beleuchtet auch eine weitere Studie:

Biological differences between men and women contribute to many sex-specific illnesses and disorders. Historically, it was argued that such differences were largely, if not exclusively, due to gonadal hormone secretions. However, emerging research has shown that some differences are mediated by mechanisms other than the action of these hormone secretions and in particular by products of genes located on the X and Y chromosomes, which we refer to as direct genetic effects. This paper reviews the evidence for direct genetic effects in behavioral and brain sex differences. We highlight the ‘four core genotypes’ model and sex differences in the midbrain dopaminergic system, specifically focusing on the role of Sry. We also discuss novel research being done on unique populations including people attracted to the same sex and people with a cross-gender identity. As science continues to advance our understanding of biological sex differences, a new field is emerging that is aimed at better addressing the needs of both sexes: gender-based biology and medicine. Ultimately, the study of the biological basis for sex differences will improve healthcare for both men and women.

Quelle: The genetics of sex differences in brain and behavior

Zu den „Four Core Genotypes“

The „four core genotypes“ (FCG) model comprises mice in which sex chromosome complement (XX vs. XY) is unrelated to the animal’s gonadal sex. The four genotypes are XX gonadal males or females, and XY gonadal males or females. The model allows one to measure (1) the differences in phenotypes caused by sex chromosome complement (XX vs. XY), (2) the differential effects of ovarian and testicular secretions, and (3) the interactive effects of (1) and (2). Thus, the FCG model provides new information regarding the origins of sex differences in phenotype that has not been available from studies that manipulate gonadal hormone levels in normal XY males and XX females. Studies of the FCG model have uncovered XX vs. XY differences in behaviors (aggression, parenting, habit formation, nociception, social interactions), gene expression (septal vasopressin), and susceptibility to disease (neural tube closure and autoimmune disease) not mediated by gonadal hormones. Some sex chromosome effects are mediated by sex differences in dose of X genes or their parental imprint. Future studies will identify the genes involved and their mechanisms of action.

Quelle: What does the „four core genotypes“ mouse model tell us about sex differences in the brain and other tissues?

Das scheint mir recht interessante Forschung zu sein. Mal sehen, was sie noch erbringt.