Navigation Links
Greater g factor in men responsible for sex differences in general mental ability

An astonishing recent discovery is that men have a 4- to 5-point IQ advantage over women by adulthood. This was confirmed by a study conducted on 100,000 17- to 18-year-//olds on the Scholastic Assessment Test (SAT).

During the school years, the sex difference is not obvious because girls mature faster than boys. This is the reason why sex difference was not detected for years.

145 items from the SAT were examined by a study published in the September 2006 issue of the journal Intelligence. It revealed that there was a male IQ advantage of 3.63 points.

It also found that the g factor--the general factor of mental ability underlay both the SAT Verbal (SAT-V) and the SAT Mathematics (SAT-M) scales with the congruence between these components greater than 0.90, and that it was the g factor that predicted student grades better than the traditionally used SAT-V and SAT-M scales.

The male and the female g factors were congruent in excess of .99, and they favored males to an equivalent of 3.63 IQ points.

The male-female differences were present at every socioeconomic level, and across several ethnic groups. The average male advantage was found "throughout the entire distribution of scores, in every level of family income, for every level of fathers' and of mothers' education, and for each and every one of seven ethnic groups," said J. Philippe Rushton, professor of psychology at the University of Western Ontario, one of the authors of the study.

The paper's results dovetail with those from several other recently published studies showing that men--surprisingly--have a 4- to 5- IQ point advantage over women by late adolescence and early adulthood. Before that age the two sexes are equal in general intelligence.

As such, the findings overturn a 100-year consensus that men and women average the same in general mental ability.

Because girls mature faster than boys, the sex difference is masked du ring the school years. Since almost all the data showing an absence of sex differences were gathered on school children, this might explain why the sex difference was missed for so long.

For decades, however, psychologists have accepted that men and women differ in their test "profiles," with males averaging higher on tests of "spatial ability" and females higher on tests of "verbal ability." These differences were assumed to average out.

The authors of the study, psychologists Douglas N. Jackson and J. Philippe Rushton at the University of Western Ontario, conducted the study because two recent sets of observations had raised anew the question of sex differences in general intelligence.

The first was that the general factor of mental ability--g--was found to permeate all tests to a greater or lesser extent. Thus, a "spatial" test may be relatively high on g (mental rotation) or low (perceptual speed), a "verbal" test may be relatively high (reasoning) or low (fluency), as may a "memory" test be high (repeating a series in reverse order) or low (repeating a series in presented order).

More than any other factor, the test's g loading best determines a test's power to predict academic achievement, creativity, career potential, and job performance. Hence, the question of sex differences became formulated more precisely as: "Are there sex differences on the g factor?"

Another set of observations concerned the sex difference found in brain size and the relation between brain size and cognitive ability. Studies published in 1992 at the University of Western Ontario by zoologist C. Davison Ankney, and also by psychologist Rushton, showed men average a 100-gram advantage over women in brain weight (and volume).

A 1997 study in Denmark documented that men have 15% more neurons than women (22.8 versus 19.3 billion). Over two-dozen Magnetic Resonance Imaging studies have confirmed a brain-size/IQ correlation of about 0.40. So, if males average a larger brain, shouldn't they also average a higher IQ score?

British psychologist Richard Lynn at the University of Ulster in Northern Ireland, and Paul Irwing at the University of Manchester found that adult men consistently average 4 to 5 IQ points higher than adult women in a series of recent large-scale studies using a number of intelligence tests in various countries. (Irwing & Lynn's most recent paper appeared in Nature on July 6, 2006.)

Other researchers too have found a male advantage in general mental ability, including Prof. Helmuth Nyborg at the University of Aarhus in Denmark, who earlier this year was disciplined by his university for talking to the media about his "politically incorrect" conclusions.

Prof. Rushton agreed that "these are unpopular conclusions." He said, "only more data can determine the true nature of sex differences in cognitive ability. However, people should not be made to feel afraid to study controversial issues."

Prof. Rushton accepted that sex differences in general mental ability could help explain the "glass ceiling" phenomenon. But he also noted the paradox that although men may have higher IQ scores, women do increasingly well in school exams.

It will be very hard to argue that selection bias caused the sex difference in this data set, the authors wrote. "That would require the assumption that there are hypothetical respondents who, if tested, would provide a compensating female-male advantage in g that would counterbalance the findings. They would have to be found at every level of SAT performance, in every level of family income, for every level of fathers' and of mothers' education, and for every ethnic group examined."


Related medicine news :

1. Greater volume hospitals better for stroke
2. Cancer Patients At A Greater Risk Of Developing Blood Clots
3. Babies Born By C- section At A Greater Risk for Allergies
4. Creating A Greater Awareness Among Smokers
5. Women At A Greater Risk For Heart Failure
6. WHO Calls For Greater Emphasis On Combating AIDS
7. Motorcycles Cause Greater Pollution
8. Vitamin D in Pregnancy Linked To Greater Bone Densities in Children
9. Risk of Heart Disease Greater from Mom than Dad
10. HIV Prevalence In Ethiopian Women Greater Than National Average
11. More Caffeine Could Mean a Greater Acceptance Tendency
Post Your Comments:

(Date:12/1/2015)... ... December 01, 2015 , ... Lutronic, a leading innovator of ... latest addition to the devices for sale in the United States. Clarity is ... long-pulsed 1064 nm Nd:YAG lasers, into a single platform that is easy to own ...
(Date:12/1/2015)... ... 01, 2015 , ... PYA’s latest white paper, “ PYA ... main “pain point” for merging or aligning healthcare provider organizations—when mergers and other ... This quick-read guidance suggests that failing to recognize the power of an ...
(Date:12/1/2015)... ... December 01, 2015 , ... PartnerTech , a leader ... leadership since 2008. Gary Bruce, President of PartnerTech North America, currently serves as ... significant amount of time in Sweden since joining PartnerTech based in Malmo, Sweden. ...
(Date:12/1/2015)... ... ... Nurotron Biotechnology Co., Ltd., maker of cochlear implant systems, has won a tender ... be from the China Disabled Persons’ Federation, a central government association, for nearly 2,000 ... and adults suffering from severe and profound hearing loss . The company holds ...
(Date:12/1/2015)... (PRWEB) , ... December 01, 2015 , ... ... Trust on receiving the 2015 HSJ Acute Sector Innovation Award on November 18th. ... the patient care experience, and propose exciting enhancements to the medical landscape. , ...
Breaking Medicine News(10 mins):
(Date:12/1/2015)... 1, 2015 A federal court has denied the ... a lawsuit filed by the Pharmaceutical Care Management Association (PCMA) ... a new law that forces employers and consumers to pay ... Arkansas must now defend a law that raises ... and CEO Mark Merritt . --> ...
(Date:12/1/2015)... 2015  Athletic apparel company Tommie Copper ... pay $1.35 million to settle Federal Trade Commission ... compression clothing would relieve severe and chronic pain ... Tommie Copper,s proposed settlement ... its founder and chairman Thomas Kallish ...
(Date:12/1/2015)... , Dec. 1, 2015 Assurex ... its GeneSight® Psychotropic test giving healthcare providers an expanded ... decisions for patients suffering from depression, anxiety, bipolar ... behavioral health conditions. i . ... --> With the addition of two new ...
Breaking Medicine Technology: