Men are Smarter than women, New Findings

Men Are Smarter Than women

The most recent evidence

The subject of gender differences in general intelligence has always been a provocative issue in the history of psychology. Let’s begin with the concept of general intelligence before reviewing the scientific evidence.

What is General Intelligence?

 The ability to understand and solve mental problems is called “General intelligence”. Terms like IQ, General Factor, g factor or simply intelligence all refer to General intelligence.
 Intelligence includes a set of different skills and components such as logical (Mathematical), spatial (e.g. mental rotation) and verbal intelligence (e.g. language and writing). General Intelligence (g) is the shared core of these components underlying almost all recognized types of intelligence. It is equivalent to “mental energy” indicating brain efficiency in information processing [1].

Differences between men and women in IQ:

In July 2012, a story was published in the media claiming that based on James Flynn’s data, women have surpassed men in IQ tests and they have become smarter than men for the first time! However, a few days later, James Flynn in his speech at Cambridge said that the media has “distorted” his results and has “gone beyond his findings” [2].
Dr. Flynn who had published a journal paper, entitled ‘Modern men match men on Raven’s Progressive Matrices’, reported a negligible IQ difference between men and women (less than one point). Contrary to what the media implied, Flynn’s data was not the most recent one as he had collected results of IQ tests between 1984 to 2000.
 Anyway, James Flynn has been extremely criticized in his previous studies by outstanding experts like Professor Arthur Jensen, due to his “selective reporting”, “insufficient sampling” and incorrect statistical methods [3].

So, what is the true story?

For almost one century the only consistent result in gender differences in IQ was females’ higher verbal skills and Males’ higher spatial abilities. The consensus among psychologists was that men and women get equal IQ scores on average. In early 90’s this view was challenged for the first time.

Richard Lynn’s Developmental Theory:

Professor Richard Lynn , who took his PhD at the University of Cambridge and was a distinguished psychology professor, realized that there was a sort of variable trend in boys’ and girl’s development in Intelligence and proposed his developmental theory of intelligence in 1994 stating that boys become more intelligent than girls after puberty (from 16 onwards).
 Prior to his findings, MRI studies of men and women’s brains had predicted the existence of gender differences in general cognitive ability. Dr. Richard Lynn and his colleagues continues their research and in 2003 and 2005 performed a meta-analyses of 57 researches in different countries and another one of 22 university samples in the USA and found a male advantage of 4.5 to 5 IQ points [4].

Also, the most recent research in this field published in 2011 by Dr. Paul Irwing from the University of Manchester revealed an advantage of 3 IQ points among men. Dr. Irwing discussed that using Wechsler test (WAIS III) on an American standardized sample has given underestimation of the true gender difference because of the test limitations.
 The results from the Scholastic Aptitude test on 100,000 17 to 18-year-olds in the United States analyzed by Professor Philippe Rushton from the University of Western Ontario in Canada in 2006 revealed boy’s higher general intelligence about 4 points [5].

Professor Helmuth Nyborg, a psychologist from Denmark in 2005 found that adult males are more intelligent than adult females about five IQ points. A committee of experts was assembled by the University of Aarhus in Denmark to look into Nyborg’s finding and investigate accusations of scientific dishonesty against him. The committee confirmed his conclusion and estimated a difference of 4.55 points favouring men.

Examples of other new researchers confirming higher male IQ and Lynn’s developmental theory are:

Gerhard Meisenberg (2009), on a sample of 22-23 American adults,

Nicholas John Mackintosh et al. (2005) from the University of Cambridge on a group of 17-18 year old students in England,

Ricarda Steinmayr et al. (2006, 2010) at Heidelberg University on samples of 16-43 year olds in Germany.

The magnitude of gender difference found in these three researches was about 6 IQ points and higher [4].

What about Recent Years?

The fact that boys surpass girls in terms of intelligence from the age of puberty into adulthood has not changed in recent years. Most of the latest studies confirm that boys begin to show higher general intelligence than girls from the age of 16 and this trend continues until early twenties when this difference reaches its eventual value of 4 to 6 points in adulthood and remains approximately constant until the ages of 80-89. For instance, considering a [6] new study of gender differences on 12 to 18-year-olds in 2002, the same pattern is observable:

Girls were slightly and temporarily smarter at ages 11 to 13 about 1.7 points, but boys started to forge ahead of girls at the age of 16 by 1.3 points and this male advantage increased to 4.3 between the ages of 17-18.

Possible Explanations of Men’s Higher Intelligence:

Richard Lynn states that some of inconsistencies in IQ test results in the past century were related to researchers’ reliance on school samples and therefore missing the disparity that emerges after puberty between the sexes. It is worth mentioning that contrary to public perception, brains of smartest children mature later than less intelligent ones [6]. Moreover, new evidence shows that modern human has a longer childhood period and takes about 19 years to grow up compared to our closest species like Neanderthals or chimpanzees who become fully mature at the age of 11. This prolonged period of childhood and slow maturation may help human brain develop more synaptic connections and facilitate complex cognition [7].

 The Puberty Process involves a growth spurt in human and this physical and mental development stops gradually at the end of this stage. The faster maturation of girls gives them a short-term advantage in Intelligence between the ages of 11 to 13 (when boys have not started their maturation). From 14 to 16, boys’ growth also accelerates while by age 16 girls’ development begins to decelerate relative to boys. After this age, boys’ growth along with further brain development still continues, leading to a higher intelligence at the end of maturation process.
 Obviously, girls do not lose any IQ points after puberty, but boys start to overtake them at this age. The male advantage in intelligence cannot be assigned to discrimination against women or other social deprivations as these researches have been conducted in western countries in recent years. The IQ gap is present at all social and income levels and there are no distortion s in the data indicating a social effect on the results [5].

To check the possibility of any sampling errors caused by elimination of low IQ men (e.g. School dropouts), Dr. Satoshi Kanazawa from the University of London and Dr. Lynn conducted a longitudinal, measuring children’s IQ’s at the age of 7 and again at the ages of 11 and 16. Girls’ intelligence was 0.8 points on average higher from 11-13 but boys became 1.5 points smarter at the age of 16. Dr. Kanazawa believes that Lynn’s developmental theory is going to be a new consensus on IQ differences in 21st century [4].
 The effect of this 5 IQ difference is to produce a male-female ratio at high IQ levels ; There are twice as many men with IQ’s of 120-plus as there are women and 30 times as many men with IQ’s of 170-plus as there are women. The possibility of a greater variance in male population has not been observed in many cases and needs to be explored further.

Intelligence and Achievements:

While girls get better grades at school on average and continue to achieve more university degrees, their eventual scientific and research output is way below those of men. Based on the most recent data in 2011, men hold more than 80 percent of patents in all fields [9] in the US. Men have won eight times as many scholarly awards as women did in science and medicine between 2001 and 2010 (nearly 90% of research-based awards [10]).
 Until 2011, men have won 99 percent of Nobel prizes in physics and economy, 95 percent of medicine/physiology and 97 percent of Nobel prizes in chemistry [9]. This disparity appears from younger ages when boys significantly outperform girls in most fields of International Student Olympiads; in 2012, 98% of gold medallists In Math Olympiad [10] and 100% of all 45 gold medallists in Physics Olympiad were male students [8]. According to the evidence form history, “men have made 98% of world’s contribution to knowledge.” [3]

Many experts believe that the present education system, with its more compatibility with female personality traits, has caused boys to lag behind girls in many countries. Recently, after changing the assessment method in the United kingdom in 2010, boys could narrow the gap and even achieve more A* grades than girls in 2012 (girls’ grades did not decrease). The educational system needs a series of reforms to help boys and girls achieve their full intellectual and academic potentials.

References: 

[1]	L. S. Gottfredson, “The General Intelligence Factor,” [Online]. Available: http://www.psych.utoronto.ca/users/reingold/courses/intelligence/cache/1198gottfred.html.
[2]	S. B. Kaufman, “Men, Women, and IQ: Setting the Record Straight,” [Online]. Available: http://www.psychologytoday.com/blog/beautiful-minds/201207/men-women-and-iq-setting-the-record-straight/comments.
[3]	A. R. Jensen and J. P. Rushton, “The rise and fall of the Flynn effect as a reason to expect a narrowing of the Black-White IQ Gap,” Intelligence, 2010.
[4]	R. Lynn and S. Kanazawa, “A longitudinal study of sex differences in intelligence at ages 7, 11 and 16 years,” Personality and Individual Differences, 2011.
[5]	D. N. Jackson and J. P. Rushton, “Males Have Greater g:Sex differences in general mental ability,” Intelligence, 2006.
[6]	R. Colom and R. Lynn, “Testing the developmental theory of sex differences in intelligence 12-18,” Personality and Individual Differences, 2002.
[7]	J. Hamilton, “Study Makes Case for Late Bloomers,” [Online]. Available: http://www.npr.org/templates/story/story.php?storyId=5310107.
[8]	“A long childhood is of advantage,” [Online]. Available: http://www.mpg.de/617475/pressRelease20101111.
[9]	“Intellectual Property and Women,” [Online]. Available: http://nwbc.gov/sites/default/files/IP%20&%20Women%20Entrepreneurs.pdf.
[10]	[Online]. Available: http://www.sciencedaily.com/releases/2012/05/120508142622.htm.
[11]	“All Nobel Prize Winners by Gender,” [Online]. Available: http://chartsbin.com/view/3069.
[12]	“International Math Olympiad,” [Online]. Available: http://www.imo-official.org/default.aspx.
[13]	“Gold medalists,” [Online]. Available: http://www.ipho2012.ee/gold-medalists/.