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This category was nominated for deletion on 3 November 2007. The result of the discussion was keep.

Here are some complaints I have about this section. Since I am being censored and wikipedia is giving an incredibly biased picture under a concerted assault by fanatics, I am forced to post in the talk page:

1. Framing/Context

They describe the issue in terms of differences in intelligence between "races," which creates an inacurate pattern in the mind of the reader. The pattern is a pattern of consistent group differences between large population groups, this makes a genetic basis for differences in IQ between various groups appear genetic.

The reality is that groups that are very closely related genetically can differ greatly in IQ. For example Japanese and Koreans living in Japan. Koreans living in Japan have far lower IQ's then the Japanese, yet when they move to america they perform about as well as the Japanese. These differences are seen throughout the world, Catholics vs. Protestants in North Ireland, Castes in India, etc. By framing it in terms of Africans vs. everyone else they make a genetic hypothesis seem far more feasible then it is.

2. Inaccuracies:

a) Rushtons bogus craniometry is sited as established fact, it is not. Differences in brain size established as uncontroversial fact, they are not.

b) Claims that they are persecuted for being "politically incorrect," simply false. In the US not a single one of them has ever been fired that I am aware of, Arthur Jensen kept his job at Berkley for atleast 2 decades after claiming blacks were inferior to whites.

c) Treatment of "Occidental Quarterly," and "Journal of Mankind" as scholarly works. Absolutely false, they are not academic research periodicals. They are the creations of Eugenicsts and Racists for advocacy purposes.

3. Sins of ommiting:

a) They completely ommit the closest thing we have to direct evidence either way. Studies conducted in the 1970's reveal that there is no relationship between percentage of african ancestory and IQ. The children of American GI's and German women, where the children were raised in Germany as Germans, show no difference in IQ between biracial children and white children. There is a whole slew of studies that I won't bore you with. Suffice is to say, ALL the direct evidence contradicts the hereditarian hypothesis.

b) Presents the issue from a very narrow prospective and ignores the vast number of viewpoints that disagree with them. They focus on the disagreement between hereditarian "G" theorists and a few critics, and completely ignore the rich array of literature on the issue from other prospectives. They focus entirely on "g" psychometry and ignore other theories and measures of intelligence within psychology (Piaget, multiple intelligences, information processing, etc.).

They also completely ignore all the sociological, linguistic, and anthropological view points that contradict their view. They present a question that is sociological, etc., in terms of a narrow psychological theory and it's opponents.

c) They ommit the highly questionable underpinnings in "g" theory. Essentially IQ tests are graded on a curve where there is a fixed percentage of 100's, 101's, 102's, etc. Frequently a 5 point difference will involve getting one answer right or wrong. There are deep methodological errors in the psychometric approach, these are well documented and are a major source of criticism.

I have many, many more complaints with the article and how it is tilted, but that is all I can fit in for now.

More on head measuring

They uncritically post craniometric data as fact, data that was the work of J. Philippe Rushton and other scientefic racists. My objection to this is two-fold, this data is most certainly fraudulent, it is certainly misleading and innacurate. The main correlation with brains size is hight/size, because of this the average Black/White brain is allmost certainly much larger then the average asian brain (not proportionaly, but in absolute terms). But they list Rushtons finding that the black brain is much smaller then the white brain and the asian brain as slightly larger then the white brain.

If scientists wanted to see if there was a link between IQ and brain size, but they had to first adjust for hieght, because hieght is correlated with IQ. That doesn't preclude the possibility that tall people have bigger brains and therefore higher IQ scores, it just controls for sociological factors. The problem of course is that, I am fairly sure of this, the head varies less in size then the rest of the body. In other words very short people will appear to have larger brains if measured proportionally to there total size, but this doesn't mean larger brains in absolute terms. There are other problems such as how body size would impact brainsize, it might not be simply hieght but also bulk.

Stephen Jay Gould in fact points out a large number of problems, problems that would make it impossible to conduct such studies. Factors such as age, nutrition, health, drug use, etc. can radically alter the size and wieght of the brain. He also recalculated Mortons data from the 19th century and uncovered a huge number of mistakes in Mortons figures, mistakes that indicated a systematic bias. Morton is widely cited in textbooks as an example of how personal bias will lead to the sort of mistakes made (they were all made in Mortons favor).

To make a long story short there is allmost no way to adjust for all the factors(age, size, etc.) that could sway the figures in one direction or the other. At anyrate brain size is a terrible means for measuring intelligence, Neandrethals (who were very closely related to Humans, but went extinct) had signifigantly larger brains IIRC, and yet are usually seen as less intelligent.

The truth about Race and Intelligence: No correlation

There is a movement to establish a connection between Race and Intelligence, they use differences in IQ test scores between ethnic groups within the united states to prove this. They do not do research that could disprove their thesis, rather they publish there work in small eugenicist magazines where they are not subject to peer review.

Others who do not hold their views have conducted research that disproves their conclusions, this research difinitively proves there is no link between race and intelligence (among blacks and whites). The cause of the gap in the United States has been firmly established as not genetic:

A Philidelphia study examined 3000 African Americans and found no link between the degree of white ancestory and IQ.*

A study conducted in the 1970's examined two samples of African Americans and found no correlation between degree of white ancestory and IQ. In fact in one study the correlation went in the "wrong" direction (ie. the more african ancestory the higher IQ).**

In a study involving Carribean children showed that there was no genetic basis for the IQ gap between blacks and whites, rather it showed the black children to be considerably more intelligent. The IQ of the children at the Orphanage was: Blacks 108, Mixed 106, White 103.***

In a study comparing the offspring of American GI's and German women, where the children where raised in Germany as Germans there was no correlation found between IQ and Race. Both the Biracial and German childredn had average IQ's of 97.****

Many "G" theorists mantian that the gap in white and Black IQ scores in the US (they claim it to be 15 points) reflects differences in innate cognitive ability, scientists who are not "g" theorists (the vast majority) contest this. The hereditarians have never conducted any serious research to prove their case.

• Scarr., S., Pakstis, S. Katz, H and Barker. (1977) "The abscense of a relationship between degree of white ancestory and intellectual skills within the Black population," Human Genetics, 39:69-86

• • Loehlin, J.D., Vandenberg, SG and Osbourne, R.T (1973) "Blood-group genes and Negro-White ability differences" Behavioral Genetics 3: 263-77

• • • Tizard, B., Cooperman, A and Tizard, J. (1972) "Enviromental effects on langauge development a study of young children in longstay residential nurseries." Child Development, 43: 342-3

• • • • Flynn, JR, (1980) "Race, IQ, and Jensen." London Routledge and Kegan Paul.

Black Supremacy?

IQ differences between black and white populations in the UK and elsewhere are virtually non-existent. In fact, Blacks of African descents in the UK, on average, earn more money and obtain higher levels of education than the native white populations (Bhattacharyya, Ilson, Blair, 2000). According to the London daily times (January, 23, 1994, as reported in Stringer and McKie 1997:190; Re-reported by Smedley in Lieberman 2001:p87) “Black Africans have emerged as the most highly educated members of British society, surpassing even the Chinese as the most academically successful ethnic minority.”

In the U.S. Black immigrants from Africa average the highest educational attainment of any population group in the country, including whites and Asians (See Logan & Dean, 2003).

Tobias (1970) listed a number of difficulties involved in measuring and making meaningful comparisons of brain weight. These included equating subjects on age, sex, body size, temperature etc. In addition, brain development is plastic, and brain size may be affected by early environmental factors. Because of all these difficulties, Tobias (1970) concluded that no adequate racial comparative studies had actually been conducted.

Interestingly enough, the brain size of American blacks reported in Tobias’s summary were larger than any white group, (which include American, English and French whites) except those from the Swedish sub sample (who had the largest brains of any of the 77 national groups measured), and American blacks were estimated to have some 200 million more neurons than American whites (See Tobias 1970; Weizmann et. al 1990).

Ironically, many of the racial researchers of today who make claims about racial differences in brain size cite Tobias (1970) as one of their main sources while ignoring the findings reported in his work; I.E. Blacks on average had larger brains than virtually all other population groups!

The main correlation with brain size is height/size; because of this the average black/white brain is certainly larger than the average Asian brain (not proportionally, but in Absolute terms). Witelson’s, Kigar’s and Thomas’ (1999) examination of Albert Einstein’s brain illustrates that something more complicated than a brain’s size relates to it’s owner’s intelligence. They compared Einstein’s brain with an average specimen from a sample 35 intact, control brains. Einstein’s brain has about the same dimensions and the same weight as the comparison brain. However, in areas specific to Einstein’s unique skills, his brain was quite different. This leads one to conclude that it is overall brain structure and not brain size that determines one’s intellectual strengths.

If you are interested in learning about the nature and nurture of brain development I suggest researching the work of Joan Stiles (Developmental Cognitive Neuroscientist, UCSD).

You may also view a presentation of her work, here: <ahref="http://video.google.ca/videoplay?docid=5991955507070826102&q=joan+stiles">The nature and nurture of brain development</a>

There is also research that shows people with higher IQ scores to be lacking in skills relating to Practical Intelligence (See Sternberg 2001, and 2004). That is, IQ and Practical intelligence skills correlate negatively. Further, Sternberg demonstrates that tests of Practical intelligence are better at predicting job performance and real world success.

Leon J. Kamin (Bell Curve Wars, 1995 p.92): “Extensive practice at reading and calculating does affect, very directly, one's IQ score.”

Race and Genetics:

- A study conducted by Tizard and colleagues involving Caribbean children showed that there was no genetic basis for IQ differences between black & whites. The IQ of the children at the Orphanage was: Blacks 108, Mixed 106, and White 103 (James R. Flynn, 1980. Richard E. Nisbett, 1994. Also see, The Bell Curve wars, 1995).

- IQ differences in the U.S. are not as drastic as some would have you believe. Many researchers put the difference between 7-10 points (Richard Nisbett, 2005; Vincent, 1991; Thorndike et al, 1986; Leon J. Kamin, 1995; Dickenson & Flynn, 2002). As well, this conclusion is only reached after lumping the entire black population together as a single body. The truth is blacks from different regions in the U.S. differ markedly in culture and achievement.

- In more than a dozen studies from the 1960s and 1970s analyzed by Flynn (1991, 2002), the mean IQs of Japanese- and Chinese American children were always around 97 or 98; none was over 100. These studies did not include other Asian groups such as the Vietnamese, Cambodians, or Filipinos; who tended to under perform academically and on conventional psychometric tests in contrast to the former groups mentioned (See Flynn, 1991).

- Adjustments for socioeconomic conditions almost completely eliminate differences in IQ scores between black and white children. Co-investigators include Jeanne Brooks-Gunn and Pamela Klebanov of Columbia's Teachers College, and Greg Duncan of the Center for Urban Affairs and Policy Research at Northwestern University.

- Osbonre and Suddick (1971, as reported in Loehlin, 1975) attempted to use 16 blood-groups genes known to have come from European ancestors. Testing two samples the authors found that the correlation

—The preceding unsigned comment was added by 70.68.179.142 (talk) 01:29, 10 February 2007 (UTC).

Intelligence

What is intelligence? Is intelligence, fundamentally, 1 import thing (Spearman, 1904), 3 things (Sternberg 1988), 7 things (Gardner, 1983), 10 things (Gardner 1999), 120 things (Guildford, 1967), or even 150 or more things (Guilford, 1982)?

Thorndike, Hagen & Sattler (1986) point out the extent to which the history of intelligence is in part a battle over names.

“Perhaps the best way to achieve coherence in the field of intelligence is to recognize that no single correct “model” or “approach” is evident and that different ones elucidate different aspects of a very complex phenomenon (Sternberg et. al 2003).”

Wagner (1978) had Moroccan and North American individuals remember patterns of Oriental rugs and others remember pictures of everyday objects, such as a rooster and a fish. Moroccans who have long experience in the rug trade seemed to remember rug patterns better than the North American individuals.

Serpell (1979) had Zambian and English children perform a number of tasks. He found that English children did better on a drawing task, but that Zambian children did better on a wire-shaping task

Lave (1988) Showed that housewives in Berkeley California who could successfully do the mathematics needed for comparison shopping were unable to do the same mathematics when they were placed inside a classroom environment.

Carraher, Carraher, and Schliemann (1985) studied a group of Brazilian street children. The investigation found that the same children who are able to do the mathematics needed to run their street businesses were often unable to do mathematics in a formal setting.

Cole, Gay, Glick and Sharp (1971:233) made the following insightful observation: “ Cultural differences in cognition reside more in the situations to which particular cognitive processes are applied than in the existence of a process in one cultural group, and its absence in another.” A similar position is held by Berry (1974).

Sarason and Doris (1979) view intelligence as a cultural invention that does not hold true across cultures.

(Serpell, 1974; Super, 1983; Wober, 1974) Even within a given society, different cognitive characteristics are emphasized from one situation to another and from one subculture to another. These differences extend not just to conceptions of intelligence but to what is considered adaptive or appropriate in a broader sense.

Views of intelligence vary from culture to culture; and the majority of these views do not reflect Western ideas (See, Berry & Bennett, 1992; Greenfield, 1997; Okagaki & Sternberg, 1991; Serpell, 1993; Yang & Sternberg, 1997)

We need to reduce the bias toward measuring intelligence through logical/mathematical and linguistic abilities and move toward looking more directly at a specific intelligence in operation (Gardner, 1993).

Howard Gardner is vocal about his disdain for a singularly psychometric approach to measuring intelligence based on paper and pencil tests. Secondly, he responds to the belief that an intelligence is the same as a domain or a discipline. Gardner reiterates his definition of an intelligence and distinguishes it from a domain which he describes as a culturally relevant, organized set of activities characterized by a symbol system and a set of operations (See Gardner; Phi Delta Kappan, 1995).

“Often intelligence tests measure skills that children are expected to acquire a few years before the taking the test (Sternberg, Presidential addresses; Culture and Intelligence, 2004).”

“Vernon (1971) points out the axes of a factor analysis do not necessarily reveal a latent structure of the mind but rather represent a convenient way of characterizing the organization of metal abilites. Vernon believed that there is no one ‘right’ orientation of axes. Indeed, mathematically an infinite number of orientations of axes can be fit to any solution in an explanatory factor analysis (See Sternberg, 2004).”

The two most widely used standardized tests of intelligence are the Wechsler scales and the Stanford-Binet. Both instruments are psychometrically sound, but Gardner believes that these tests measure only linguistic and logical/mathematical intelligences, with a narrow focus within content in those domains. According to Gardner, the current psychometric approach for measuring intelligence is not sufficient (Gardner, 1993).

Robert Sternberg and his colleagues ask the experts to define “intelligence” according to their beliefs. Each of the roughly two dozen definitions produced in each symposium was different. There were some common threads, such as the importance of adaptation to the environment and the ability to learn, but these constructs were not well specified. According to Sternberg, very few tests measure adaptation to environment and ability to learn; nor do any tests except dynamic tests involving learning at the time of the test measure ability to learn. Traditional tests focus much more on measuring past learning which can be the result of many factors, including motivation and available opportunities to learn (Sternberg, Grigorenko, and Kidd, American Psychologist, 2005).

In Kenya, those schoolchildren whose traditional skills are most prized by the community tend to do least well in school tests (Sternberg & Grigorenko, 1997; Sternberg, Nokes, et al., in press). In Brazil, street children who run a successful street business typically fail mathematics in the school setting (Ceci & Roazzi, 1994). In the West, school-based tests show correlations with career success, but they are also major gatekeepers of academic and vocational routes to advancement (Sternberg, 1997).

IQ test items are largely measures of achievement at various levels of competency (Sternberg, 1998,1999, 2003). Items requiring knowledge of the fundamentals of vocabulary, information, comprehension, and arithmetic problem solving (Cattell, 1971;Horn, 1994).

IQ scores do change over time. The average change between age 12 and age 17 was 7.1 IQ points; some individuals change as much as 18 points (Jones & Bayley, 1941).

“Individuals do not necessarily exhibit their "intelligence" in its raw state. Rather, they prepare to use their intelligence by passing through a developmental process. Thus, people who want to be mathematicians or physicists, spend years studying and honing their logical/mathematical abilities in a distinctive and socially relevant way (Gardner, 1999).”

Instruments developed to quantify smartness are culturally based and cannot simply be "transplanted" to a culture with different values (Greenfield, 1997).

In addition to learned reasoning abilities, IQ measures little more than a person's ability to take an IQ test, as scores increase dramatically as a person is trained or familiarized with the tests (See Kamin, 1974).

"Intelligence is a biopsychological potential to process information that can be activated in a cultural setting to solve problems or create products that are of value in a culture (Gardner, 1999a), "

Scientists Richard Lewontin, Ruth Hubbard, and Howard Taylor have conclusively demonstrated that there is no scientific basis for any claims of a genetic, hereditary component of variations in "intelligence."

Research has shown that IQ type tests account for about 10% of the variation in how successful people are in various aspects of their adult lives. 10% isn't much and, maybe it's a coincidence, but when I ask people what it takes to be successful on the job or in a personal relationship and what it takes to be successful on one of these tests, or in an introductory classroom, the overlap is probably about 10% (Robert Sternberg, interview with Frontline).

IQ is a culturally, socially, and ideologically rooted concept. It could scarcely be otherwise, as this index is intended to predict success (i.e., to predict outcomes that are valued as success by most people) in a given society (i.e., in a large social group carrying its own set of values). IQ has been most studied where it was invented and where it is most appreciated, that is, in the established market economies and especially in the United States. Oddly enough, the country where its testing originated--France--largely ignores it. (The Predictive value of IQ- Sternberg et al; Merrill-Palmer Quarterly, Vol. 47, 2001)

The situation of testing itself (e.g., communicating with strangers regarding things and issues that lack context and that might appear to be meaningless) often results in the collection of unreliable data (e.g., Glick, 1968).

Intelligence is not a characteristic of people, but rather a potential for intelligence performance that is embedded in specific situations (Barab & Plucker, 2002).

views on smartness vary in different cultures; the majority of these views do not match Western views (Berry & Bennett, 1992; Greenfield, 1997; Okagaki & Sternberg, 1991; Serpell, 1993; Yang & Sternberg, 1997).

Gardner (1993) emphasizes two additional points about assessment that are critical. The first is that the assessment of intelligence should encompass multiple measures. Relying on a single IQ score from a WISC-III (Wechsler Intelligence Scale for Children) without substantiating the findings through other data sources does the individual examinee a disservice and produces insufficient information for those who provide interventions.

IQ tests are convenient partial operationalizations of the construct of intelligence, and nothing more. They do not provide the kind of measurement of intelligence that tape measures provide of height (See Sternberg et al, 2005).

At this point in history, the study of intelligence has moved well beyond the realm of psychometrics.

—The preceding unsigned comment was added by 70.68.179.142 (talk) 01:32, 10 February 2007 (UTC).

POV

The problem with this page is that the title is "Race and intelligence controversy". If there is a controversy then there are at least two sides to this controversy. Please propose subcategories for these categories or this will be Afd.--Tstrobaugh 20:07, 31 July 2006 (UTC)

I'm not sure I understand what the concern is. The two sides of the controversy are covered in the race and intelligence article. Examples in this category are James R. Flynn and Arthur Jensen. Categories are not required to have subcategories in order to avoid WP:CFD, and it doesn't seem necessary to partition topics into categories like Category:The partly genetic hypothesis of racial differences in intelligence.--Nectar 04:47, 1 August 2006 (UTC)

• You say "Categories are not required to have subcategories" Please state your reasoning and cite a guide supporting it. My position is that the current structure violates Misplaced Pages:Naming_conventions_(categories)#General_naming_conventions "Articles should be placed in the most specific categories possible". Opposite categories is the most that rule can be violated. I thought that subcategories would solve the problem but I'd like to hear you solution.

The sentence following "Articles should be placed in the most specific categories possible" is "Categories should be more or equally as broad as the articles they contain." Currently the category is equally as broad as the race and intelligence article it represents. If the positions in race and intelligence were expanded into articles titled The partly genetic hypothesis of racial differences in intelligence and The environmental hypothesis of racial differences in intelligence than it could be argued each article should represent its own category.--Nectar 11:55, 1 August 2006 (UTC)

• "than it could be argued each article should represent its own category" exactly! Encylopedias are not arguing grounds and do not take positions. They just provide information. Let the readers make their own opinions. The mere existencd of this category is a POV. There is also already categories Category:Controversies, Category:Wikipedia_controversial_topics and Category:Philosophical_arguments. Also "it is our job to be fair to all sides of a controversy." from Misplaced Pages:Guidelines_for_controversial_articles. This article this category relates to is already on Misplaced Pages:List_of_controversial_issues and I see you participated in Talk:Race_and_intelligence. Again I have to state that I believe this category is in existence to further a POV. Look over Wikipedia_talk:List_of_controversial_issues and Misplaced Pages:Votes_for_deletion/Controversy for some more talk on the subject. As for pointing to other categories that do the same like Category:Intelligent_design_controversies i will be tackling those also.--Tstrobaugh 15:46, 1 August 2006 (UTC)
• more on POV Talk:Intelligence_(trait)#older--Tstrobaugh 18:48, 1 August 2006 (UTC)
• more on POV Categorization/Gender,_race_and_sexuality#Other_considerations--Tstrobaugh 21:38, 1 August 2006 (UTC)

Can you explain clearly and concisely why this category violates WP:NPOV? I don't have time to read a dozen links, so if there's something relevant in a link, can you quote it? --Nectar 01:51, 2 August 2006 (UTC)

—The preceding unsigned comment was added by 70.68.179.142 (talk) 01:24, 10 February 2007 (UTC).

Bogus Arguments

IQ tests scores are not an absolute measure of intelligence; they tend to ignore many aspects of human cognition and the cognitive process. Things like creatively, wisdom, ability to learn, ability to adapt and practical skills are not gauged by these tests in a meaningful way. IQ tests also fail to measure the same construct among all people to whom the tests are applied, the more culturally distinct the group (I.E. Truckers, and Musicians) the greater the discrepancy. To apply a single test to an entire population of distinct individuals from varying backgrounds is unbelievably biased unless used to gauge a particularly relevant skill. Example: Race horses are not gauged for their poker skills. - Just as Sociologists are not measured by their ability to paint.

The fact of the matter is intelligence does vary among humans, but this can be for many reasons: prenatal care, subjective interpretation, interest factors, differing environments, life circumstances etc. My concern is not with differences among individuals, but with claims that imply that group differences involving subjective and highly bias testing situations can amount to genetic differences in the traits being tested.

How does one compare the intelligence of a gifted painter with that of a mediocre Physicist? According to the narrow methods and perspectives used and held by many Psychometricians, the Mediocre Physicist is likely to be perceived the more intelligent. Why, because this is what the testing situation demands that they believe/think.

Psychometric tests do not and can not measure the number of years spent in practice, nor can they measure interest, motivation, interpretation, diet, home & social life, daily activities etc.; nor do they try! Despite these obvious and fundamental short comings this model is often presented as valid and unbiased by many practitioners.

Cole, Gay, Glick and Sharp (1971:233) made the following insightful observation: “ Cultural differences in cognition reside more in the situations to which particular cognitive processes are applied than in the existence of a process in one cultural group, and its absence in another.

Robert Sternberg and his colleagues ask the experts to define “intelligence” according to their beliefs. Each of the roughly two dozen definitions produced in each symposium was different. There were some common threads, such as the importance of adaptation to the environment and the ability to learn, but these constructs were not well specified. According to Sternberg, very few tests measure adaptation to environment and ability to learn; nor do any tests except dynamic tests involving learning at the time of the test measure ability to learn. Traditional tests focus much more on measuring past learning which can be the result of many factors, including motivation and available opportunities to learn (Sternberg, Grigorenko, and Kidd, American Psychologist, 2005). - IQ test items are largely measures of achievement at various levels of competency (Sternberg, 1998,1999, 2003). Items requiring knowledge of the fundamentals of vocabulary, information, comprehension, and arithmetic problem solving (Cattell, 1971;Horn, 1994).

Further more, IQ is not a fixed quantity; it can be raised (It is not as difficult to rise, as it is to maintain). This has been demonstrated numerously through studies involving environmental stimulation.

Examples of such studies:

In 1987 Wynand de Wet (now Dr. de Wet), did his practical research for an M.Ed. (Psychology) degree on the Audiblox program at a school for the deaf in South Africa. The subject of the research project concerned the optimization of intelligence actualization by using Audiblox. Twenty-four children with learning problems participated in the study, and were divided into 3 groups.

The children in Group A received Audiblox tuition. The children were tutored simultaneously in a group by means of the Persepto for 27.5 hours between April 27 and August 27, 1987. The first edition of the group application of the Audiblox program was followed. No diagnostic testing was done beforehand. The children in Group B received remedial education. They were tested beforehand and based on the diagnosis each child received individualized tuition on a one-on-one basis for 27.5 hours between April 27 and August 27, 1987. The children in Group C were submitted to non-cognitive activities for 27.5 hours during this period.

All 24 children were tested before and after on the Starren Snijders-Oomen Non-verbal Scale (SSON), a non-verbal IQ test that can be used for deaf children. Dr. de Wet reported that he could do nearly all the Audiblox exercises without adaptations, except the auditory exercises. Because he had to use sign-language, the children could not close their eyes. The average scores of the three groups on the SSON test were as follows:

Average IQ's before intervention, after intervention, and general Increase

IQ scores Group A (Audiblox group): 101.125 - - 112.750 - - 11.625 Group B (Remedial group): 107.125 - - 116.250 - - 9.125 Group C (Non-cognitive): 104.250 - - 108.875 - - 4.625

Reports received from the teachers indicated that the improvements achieved through remedial education and through Audiblox transferred to the general school performance of the children. The transfer scored through the Audiblox, however, was superior to that of the remedial education, says Dr. de Wet. Finally, because Audiblox can be applied in a group setting, it is much more cost effective that remedial education, he says.

Reference: De Wet, W., The Optimization of Intelligence Actualization by Using Audiblox (M.Ed. (Psychology) Thesis: University of Pretoria, 1989).

The Glenwood State School

A particularly interesting project on early intellectual stimulation involved twenty-five children in an orphanage. These children were seriously environmentally deprived because the orphanage was crowded and understaffed. Thirteen babies with an average age of nineteen months were transferred to the Glenwood State School for retarded adult women and each baby was put in the personal care of a woman. Skeels, who conducted the experiment, deliberately chose the most deficient of the orphans to be placed in the Glenwood School. Their average IQ was 64, while the average IQ of the twelve who stayed behind in the orphanage was 87.

In the Glenwood State School the children were placed in open, active wards with the older and relatively bright women. Their substitute mothers overwhelmed them with love and cuddling. Toys were available, they were taken on outings and they were talked to a lot. The women were taught how to stimulate the babies intellectually and how to elicit language from them. After eighteen months, the dramatic findings were that the children who had been placed with substitute mothers, and had therefore received additional stimulation, on average showed an increase of 29 IQ points! A follow-up study was conducted two and a half years later. Eleven of the thirteen children originally transferred to the Glenwood home had been adopted and their average IQ was now 101. The two children who had not been adopted were reinstitutionalized and lost their initial gain. The control group, the twelve children who had not been transferred to Glenwood, had remained in institution wards and now had an average IQ of 66 (an average decrease of 21 points). Although the value of IQ tests is grossly exaggerated today, this astounding difference between these two groups is hard to ignore.

More telling than the increase or decrease in IQ, however, is the difference in the quality of life these two groups enjoyed. When these children reached young adulthood, another follow-up study brought the following to light: ┨e experimental group had become productive, functioning adults, while the control group, for the most part, had been institutionalized as mentally retarded.⼢r> Other Examples of IQ Increase

Other examples of IQ increase through early enrichment projects can be found in Israel, where children with a European Jewish heritage have an average IQ of 105 while those with a Middle Eastern Jewish heritage have an average IQ of only 85. Yet when raised on a kibbutz, children from both groups have an average IQ of 115.

In another home-based early enrichment program, conducted in Nassua County, New York, an instructor made only two half-hour visits a week for only seven months over a period of two years. He spent time showing parents participating in the program how best to teach their children at home. The children in the program had initial IQⳠin the low 90s, but by the time they went to school they averaged IQⳠof 107 or 108. In addition, they have consistently demonstrated superior ability on school achievement tests.

Further References: • Clark, B., Growing Up Gifted (3rd ed.), (Columbus: Merrill, 1988). • Dworetzky, J. P., Introduction to Child Development (St. Paul: West Publishing Company, 1981). • Skeels, H. M., et al., “A study of environmental stimulation: An orphanage preschool project,” University of Iowa Studies in Child Welfare, 1938, vol. 15(4).

Leon J. Kamin (Bell Curve Wars, 1995 p.92): “Extensive practice at reading and calculating does affect, very directly, one's IQ score.”r>

Robert Sternberg on the matter of IQ gains (Interview with Skeptic magazine): "I think it's hard to maintain the IQ gains. But if you think environment is important in the development of intelligence, and you put people in a really good program and you raise their IQ, and then take them out of the program and put them back in the poor environment in which they started, chances are you are going to lose a lot of the beneficial effect. If you give someone antibiotics for a disease, cure them, then put them back in the original septic environment, the disease will return. We've seen this when we work with children with parasitic infections. We can give them Albendazol and it will cure their parasitic infection. But if you put them back in the environment in which they acquired the infection, they will just acquire it again."

I personally do not agree with his comparing of IQ with disease or infection, but his point is valid; I am sure the same can be said for a good music program or art school. I think the main problem here is maintenance. Example: If a body builder does not exercise for some time his muscle mass will decrease. Or, if an artist does not paint for some years his/her skill will diminish. In other words, “use it or loose it.” ⦮ There are many other studies that prove IQ to be a non static phenomenon and/or none genetic trait, one of the most notable and well known being the Flynn effect: This study of IQ tests scores for different populations over the past sixty years, James R. Flynn discovered that IQ scores increased from one generation to the next for all of the countries for which data existed (Flynn, 1994). This interesting phenomenon has been called "the Flynn Effect."

”Research shows that IQ gains have been mixed for different countries. In general, countries have seen generational increases between 5 and 25 points. The largest gains appear to occur on tests that measure fluid intelligence (Gf) rather than crystallized intelligence (Gc).”⼢r>

http://www.indiana.edu/~intell/flynneffect.shtml

This being said, how well do IQ tests predict real world success? - According to Stephen J. Gould the only thing an IQ test can accurately predict is how well a person scores on the test. Many others have made similar statements

Robert Sternberg on the matter of intelligence etc: My first set of interests is in higher mental functions, including intelligence, creativity, and wisdom. - I have proposed a triarchic theory of successful intelligence, and much of the work we do at the PACE Center is in validations of this theory. The theory suggests that successfully intelligent people are those who have the ability to achieve success according to their own definition of success, within their sociocultural context. They do so by identifying and capitalizing on their strengths, and identifying and correcting or compensating for their weaknesses in order to adapt to, shape, and select environments. Such attunement to the environment uses a balance of analytical, creative, and practical skills. The theory views intelligence as a form of developing competencies, and competencies as forms of developing expertise. In other words, intelligence is modifiable rather than fixed.

We use a variety of converging operations to test the triarchic theory--componential (information-processing) analyses, exploratory and confirmatory factor analysis, cultural and cross-cultural studies, instructional studies, and field studies in the workplace. The results of all of these kinds of studies have been encouraging.

Key References: Sternberg, R. J. (1977). Intelligence, information processing, and analogical reasoning: The componential analysis of human abilities.Hillsdale, NJ: Erlbaum. Sternberg, R. J. (1985). Beyond IQ: A triarchic theory of human intelligence. New York: Cambridge University Press. Sternberg, R. J. (1990). Metaphors of mind: Conceptions of the nature of intelligence. New York: Cambridge University Press. Sternberg, R. J. (1997). Successful intelligence. New York: Plume. Sternberg, R. J. (1999). The theory of successful intelligence. Review of General Psychology, 3, 292-316. Sternberg, R. J., Forsythe, G. B., Hedlund, J., Horvath, J., Snook, S., Williams, W. M., Wagner, R. K., & Grigorenko, E. L. (2000).Practical intelligence in everyday life. New York: Cambridge University Press. Sternberg, R. J., & Grigorenko, E. L. (2000). Teaching for successful intelligence. Arlington Heights, IL: Skyligh

Robert J. Sternberg (b. 8 December 1949) is a psychologist and psychometrician and the Dean of Arts and Sciences at Tufts University. He was formerly IBM Professor of Psychology and Education at Yale University and the President of the American Psychological Association

- Also see work by Howard Gardener.

Sternberg on Psychometric G (a quote from his interview with skeptic magazine): “What I found at that time was that if you use the kinds of tasks that are used in intelligence tests, then you will get the g factor. That statement reflected analyses we did that instead of using individual difference analysis used process analysis. Even using process analysis, we got a general factor. So if you were to ask me, "Do I think that there is general factor in the kinds of tests that psychometricians use?" I would say "Yes." That is a different question from, "If you define intelligence, not just as IQ, but as involving more than what the IQ tests in fact test, is there then a general factor?" then I would say the answer is "No." So the way psychometricians operationalize it, you get a g factor.”

Note: There are three major schools of psychometric interpretation and only one supports the view of g and IQ.

Race and Genetics:

- Osbonre and Suddick (1971, as reported in Loehlin, 1975) attempted to use 16 blood-groups genes known to have come from European ancestors. Testing two samples the authors found that the correlation over the 16 genes and IQ scores was not highly positive as would have been predicted if European genes in Blacks increased IQ scores. In Fact, the correlations were -.38 and +.01. Because the results were not significant, the authors concluded that European genes lower IQ scores.

- Zuckerman (1990) demonstrated the dubiousness of results obtained through race premises. He found much more variation within groups designated, and, like many other species, humans showed considerable geographical variation in morphology (p.1134). Yee, et al. (1993) further concludes this. Also see

- A study conducted by Tizard and colleagues involving Caribbean children showed that there was no genetic basis for IQ differences between black & whites. The IQ of the children at the Orphanage was: Blacks 108, Mixed 106, and White 103 (Flynn, 1980; also see Richard E. Nisbett, Race, Genetics and IQ; The Bell Curve wars, 1995).

- Adjustments for socioeconomic conditions almost completely eliminate differences in IQ scores between black and white children. Co-investigators include Jeanne Brooks-Gunn and Pamela Klebanov of Columbia's Teachers College, and Greg Duncan of the Center for Urban Affairs and Policy Research at Northwestern University.

- According to most geneticists human populations have never been separated long enough for anything but the most superficial traits to have developed; human psychical traits over lap and graduate into one another. As well, there is as much or more diversity and genetic difference within any "racial" group as there is between people of different racial groups. Traits like height and body shape offer much more genetic information than anything we use to designate the racial groups found here in North America and elsewhere. Also, what is considered black America could be considered white in Africa; that is, social ideas involving race differ from population to population." (See, Cavalli-Sforza, Menozzi, Piazza, 1994 & 2000; Davis, 1991; Allen & Adams, 1992. Yee, Fairchild, Weizmann and Wyatt, 1993; Also see Dryna, D.Manichaikul, De Lange, Snieder, and Spector, 2001; Holden, 2001)

- Also, IQ differences in the U.S are not as drastic as some have you believe. Many researchers put the difference between 7-10 points (Richard Nisbett, 2005; Vincent, 1991; Thorndike et al, 1986; Leon J. Kamin, The Bell curve wars, 1995). As well, this conclusion is only reached after lumping the entire population together as a single body. The truth is blacks from different regions in the U.S. differ markedly in culture and achievement.

- In more than a dozen studies from the 1960s and 1970s analyzed by Flynn (1991), the mean IQs of Japanese- and Chinese American children were always around 97 or 98; none was over 100. These studies did not include other Asian groups such as the Vietnamese, Cambodians, and Filipinos; who tend to achieve far less, academically.

- Stevenson et al (1985), comparing the intelligence-test performance of children in Japan, Taiwan and the United States, found no substantive differences at all. Given the general problems of cross-cultural comparison, there is no reason to expect precision or stability in such estimates.

- Charles Allen.

Further evidence against Rushton, Lynn, and Jensen coming soon!!

Why are you posting this here? This is a for discussing the category, not the article race and intelligence.

Rename category

Would it not be more neutral and more simple just to rename this category 'race and intelligence'? Some of the articles have nothing to do with controversy, so it seems inappropriate to name the category so. Richard001 06:43, 23 May 2007 (UTC)

we should add this name

I think we should add this name James D. Watson, I do not know how to add the name to this page, I hope someone help. Hasam 22:19, 17 October 2007 (UTC)

What is PZ Myers doing on this list?

To the best of my knowledge, Myers has not published any scholarly or popular work relevant to the race and intelligence debate. His statements on the topic of intelligence aren't of the kind that would garner major media attention (unlike statements made by Stephen Jay Gould or James Watson). He isn't an authority in psychometrics or any other branch of psychology. Myers is a developmental biologist whose research doesn't seem to have any bearing to this topic. I'm not aware that he has ever advanced any original thinking about the subject on his blog. (And blog posts should always be considered a questionable source when it comes to serious scientific matters on Misplaced Pages.) Furthermore, his Misplaced Pages article doesn't mention anything relating to this matter. Myers inclusion in this category needs to be justified otherwise I'm going to remove him in the near future. 24.113.82.222 07:24, 4 November 2007 (UTC)

Do Black have larger Brains?

The majority of empirical studies on the matter of racial differences in brain size suggest that blacks from comparable environments will have larger brains than do others. Brain sizes vary considerably within any species, but this variation is not usually related to intelligence. Instead, it correlates loosely with body size: large people tend to have larger brains (Gould, 1981). As a result, women on average will have smaller brains than men (Peters, 1991). However, this does not indicate that the level of male intelligence is higher than female intelligence; Neanderthals had on average larger brains than anatomically modern humans (Tattersall, 1995; Gould, 1981) but most would agree that they were considerably less intelligent than Homo sapiens (Tattersal, 1995, 2004; Gould, 1981; Mithen 1998). In addition, female brains are structured in a way that would more than make up for any size differences.

Tobias (1970) compared 7 racial and national groups in a study on brain size, in which he reported that the brain size of American blacks was larger than any white group, (which included American, English and French whites) except those from the Swedish sub sample (who had the largest brains of any of the groups measured), and American blacks were also estimated to have some 200 million more neurons than American whites (See Tobias 1970; Weizmann et al. 1990). Gould (1981, 1996) discovered upon recalculating Morton’s skull data that the crania of blacks in his sample were on average larger than those of whites. Morton included in his sample of black skulls more females than he included in the white sample. For example, in his analysis of Hottentotts (black tribe from South Africa) all measured crania were of females; the Englishmen were all mature men. Also, Morton did some early measurements with seed instead of shot. When he discovered that this method gave inconsistent results, he re did the Caucasian values with shot, but not the blacks (See Gould, 1981, 1996). After correcting these errors it was shown that the black sample had larger crania (and presumably, larger brains) than did whites (ibid).

Interestingly, during the time periods in which the data for the above mentioned studies were collected anthropomorphic research has shown that blacks were on average physically smaller in stature than whites and received poorer nutrition (e.g. Alan, 2006). Indicating that in spite of relatively lower anthropomorphic measurements and poorer nutritional intake, blacks still demonstrated larger brain volume.

Empirical evidence shows that there is virtually no correlation between the intensity of different selective force gradients (e.g. latitude/temperature) and cranial morphology (Harvati and Weaver, 2006; Keita, 2004; Roseman and Weaver, 2004; Roseman, 2004; Gould, 1981, 1996; Brace, 2001). Indeed, positive geographic selective force correlations relating to craniometric variables are usually only (vaguely) observed when people from extreme cold (arctic) environments, such as Inuit types and Siberians, are included in analysis (Roseman, 2004; Harvati and Weaver, 2006). For example, Harvati and Weaver (2006) found a weak association between cranial centroid sizes and climatic variables, which approached, but did not reach, significance. This effect disappeared when an Inugsuk (a group from Greenland similar to Eskimos) sample was removed from the analysis (ibid). Roseman (2004) observed similar findings with a Siberian sample – once the Serbian sample was removed from the analysis, there was no indication that environmental temperature or latitude played ‘any’ role in cranial morphology. In sum, recent studies comparing craniometric and neutral genetic affinity matrices have concluded that, on average, human cranial variation fits a model of neutral expectation.

Keita (2004) in his principal components analysis on male crania from the northeast quadrant of Africa and selected European and other African series also found no consistent ‘size differences’ between regional groups, as all samples showed marked variation in size. There were however some distinguishing differences in relationship to cranial shape between European and African samples, particularly with respect to nasal aperture and changes in the maxilla (part of the upper jaw from which the teeth grow). The primary goal of this study was to assess the anatomical basis of patterns of craniofacial variation along an African–European continuum, with special interest on North Africa. There was Interest in whether there was a sharp boundary separating any of these groups from each other (see Keita, 2004). In terms of overall cranial size, tropical African groups were found in many instances to have larger crania than European groups. For example, on close inspection of the 2 dimensional PC scatter plots, designating cranial size/shape, the Zulu sample appeared to have the largest crania of any group in the analysis, followed by Norse (Norway) and then Teita (Kenya). African crania were also found to be broader (wider) than European crania on average. Surprisingly, one European sample, Berg (Hungarian), correlated more closely with African samples in this respect than with other European samples. Tremendous overlap between all groups was observed in this study, for most variables (see Keita, 2004).

Extensive research in human genetics on ‘presumably’ neutral loci has also shown that the overwhelming majority of human diversity is found among individuals within local populations. Previous studies of craniometric diversity are similar to these genetic apportionments, implying that interregionally differing selection pressures have played a limited role in producing contemporary human cranial diversity (Roseman and Weaver, 2004; Brace, 2001).

Other physical anthropological research has also shown that the crania of Sub-Saharan Africans are generally wider than European and North African samples, verbatim. For example sub-Saharan specimens show a generalized vertical facial flattening, with consequent widening of the entire structure (Bruner and Manzi, 2004). This pattern involves interorbital and orbital enlargement, widening and flattening of the nasal bones and aperture, maxillary development and upper rotation, and a general widening and lowering of the face. The face shortens vertically and this flattening leads to a relative lateral enlargement of the whole morphology and maxillary frontward rotation (see Bruner and Manzi, 2004). The pattern toward the other extreme shows the opposite processes, with a general vertical stretching related to a lateral narrowing, as seen in European and North African samples (ibid).

Roseman and Weaver (2007) found that the amount of phenotypic variation in human cranial morphology decreases at the population level the further one travels from Sub-Saharan Africa. African populations tend to exhibit more cranial variation than do other world populations (Hanihara et al, 2003; Hiernaux, 1975; Keita, 2004; Roseman and Weaver, 2007). Relethford (1994) and Relethford and Harpending (1994) found that the amount of morphological variation among major geographic groups is relatively low, and is compatible with those based on the genetic data, where Africa shows the most variation. Manica et al (2007) note a smooth loss of genetic diversity with increasing distance from Africa, and along with this, using a large data set of skull measurements and an analytical framework equivalent to that used for genetic data, also show that the loss in genetic diversity is mirrored by a loss in phenotypic variability.

Genetic studies of human brainsize have discovered two genes that when mutated can result in a severely reduced brain volume, or ‘Autosomal recessive primary microcephaly’. The gene microcephalin (MCPH1) regulates brain size during development and has experienced positive selection in the lineage leading to Homo sapiens (Zhang, 2003; Evans et al, 2005). Within modern humans a group of closely related haplotypes, known as ‘haplogroup D’ arose from a single copy at this locus (Evans, 2006). Globally, D alleles are young and first appeared about 37,000 years ago; with high frequency haplotypes being rare in Asia, and particularly Africa. The highest frequencies are seen in Europe/Eurasia. The second microcephalin gene, ‘ASPM’ (abnormal spindle like Microcephaly associated), went an episode of positive selection that ended some time ago (between 6–7 million and 100,000 B.P.), with newer D variants showing positive selection arising about 5,800 years ago (Evans et al, 2005; Zhang, 2003), although some research calls into question whether these newer variants are being selected for (see Voight 2006; Yu et al, 2007).

Microcephaly genetic researchers believe that D alleles may have first arisen in an archaic homo species about 1.1 million years ago before introgression into modern Homo sapien sapiens about 37, 000 years ago; possibly as the result of interspecies breeding (Evans et al, 2006). In fact, microcephalin shows by far the most compelling evidence of admixture among the human loci examined thus far (Evans et al, 2006). Modern humans arose only 100,000 years ago in Africa (Horan et al, 2005), which would make D alleles more than 1million years “older” than modern humans, and certainly very primitive by any stretch.

Normal D variants of both ‘MCPH1’ and ‘ASPM’ genes have been shown to have mild affects on human brainsize with empirical evidence demonstrating the alleles to reduce brain volume, slightly (Woods et al, 2006). For example, each additional ASPM allele was associated with a non significant 10.9 cc decrease in brain volume. For MCPH1, each additional allele was associated with a non significant 19.5 cc decrease in brain volume (Woods et al, 2006).

While selective pressure in favor of smaller brain volume might seem counterintuitive, it should be noted that the fossil records suggest that brain size in humans – particularly in Europe - has decreased over the past 35,000 years, and on through the Neolithic period (Frayer, 1984; Ruff et al, 1997; Woods, et al, 2006). Interestingly, the selected variant of MCPH1 is thought to have arisen about 37,000 years ago (Evans et al, 2006) making it a candidate gene responsible for this general decline (Woods et al, 2006), while the ASPM variant is thought to have arisen only 5,800 years ago. These archaeological changes in brain size are paralleled by changes in body size (Ruff et al, 1997; Woods et al., 2006), and it is possible that decreases in brain size may have exerted selective pressure for corresponding decreases in body (Ruff et al, 1997; Frayer, 1984; see also, Woods et al., 2006).

The supposed rate of selection for these particular variant MCPH1 and ASPM alleles might also indicate that the genes are relatively unexpressed in the human brain, outside of causing ‘Autosomal recessive primary microcephaly.’ In one study it was shown that genes with maximal expression in the human brain tend to show little or no evidence for positive selection (Nielsen et al, 2006). For example, the microcephaly genes in question have also been implicated in the development of breast cancer (Xu et al, 2004), and other non brain related conditions (Trimborn et al, 2004). Implying that the mild brain volume reductions observed with each additional variant of ASPM and MCPH1 may in fact be adaptively unimportant. It should be further noted that one microcephalin gene (CDK5RAP2) has shown evidence of positive selection in West African Yoruba (Voight, 2006; bond et al, 2005), however, this gene at the MCPH3 locus has been least involved in causing a microcephalin phenotype (Hassan et al, 2007), and is not believed to have arisen in an archaic homo species.

Cernovsky (1990) reported that American blacks were superior in brain weight when compared with American whites. It is also known that the largest portions of the human brain are devoted to sensory and motor functions, which would mean that people with especially acute senses or strong motor skills can be expected to have larger brains than do others (Allen, 2002). It has been shown in several studies that blacks in general possess superior motor skills when compared to whites (Super, 1976; Wilson 1978; DiNucci, 1975); some believe that this may be the result of environmental and cultural factors (Super, 1976). The overall implications are the same, however, and suggest that blacks have larger brains.

TESTOSTERONE, BRAIN SIZE and PENIS SIZE…?

Some of the more desperate claims for racial differences in brain size are accompanied by highly unusual arguments suggesting racial differences in penis size (i.e. that they are inversely correlated). Thorough investigation of the formal neuroscience, anthropology, paleontology, anatomy, physiology, and ‘sex psychology’ literature reveal that legitimate references to this - ridiculous (?) - notion are not only remote, but in fact, “nonexistent.” The development and size of one’s penis is controlled by testosterone levels during puberty; and it is testosterone (and body size) that determine penis size. Testosterone: “Primary male hormone, causes the reproductive organs to grow and develop; responsible for secondary sexual characteristics, and promotes erections and sexual behavior” (1).

With this in mind; employing elementary logic one may safely arrive at the conclusion that because men tend to have dramatically higher levels of testosterone than do women (about 10 times the level), and on average have larger brains (due mostly to body size); that testosterone not only increases body and penis size, but also brain size! In fact, the relationship between larger brain size and testosterone is of common knowledge, and is well documented in the literature (e.g. Solms and Turnbull, 2002; Hulshoff Pol et al, 2006).

Moreover, low testosterone has been associated with smaller penis and testes size in humans (McLachlan and Allan, 2005). Low testosterone has also been associated with failure to go through full normal puberty, poor muscle development, reduced muscle strength, low interest in sex (decreased libido), osteoporosis (thinning of bones common in whites and Asians), poor concentration, difficulty getting and keeping erections, low semen volume, longer time to recover from exercise, and easy fatigue, in men (McLachlan and Allan, 2005). At the other (relative) extreme, high testosterone has been associated with improved health and longevity, superior motor abilities, increased reproductive success (in men), increased mental focus, larger brain volume and “boldness” in men (Dabbs and Dabbs, 2000; Solms and Turnbull, 2002; Hulshoff Pol et al, 2006; Fink el al, 2005).

With respect to brain size again; it is known that sex hormones (e.g. testosterone, estrogen) induce sexually-dimorphic brain development and organization. Research with cross-sex hormone administration to transsexuals has provided a unique opportunity to study the effects of sex steroids on brain morphology in young adulthood. Hulshoff Pol et al (2006) used magnetic resonance brain images prior to, and during, cross-sex hormone treatment to study the influence of anti-androgen +estrogen treatment on brain morphology in eight young adult male-to-female transsexual subjects and of androgen treatment in six female to- male transsexuals. The team found that compared with controls, anti-androgen (i.e. male sex hormones/testosterone) + estrogen treatment decreased brain volumes of male-to-female subjects towards female proportions, while androgen treatment in female-to-male subjects increased total brain and hypothalamus volumes towards male proportions (Hulshoff Pol et al, 2006 ). These findings have also been replicated in animal studies (Nottenbohm, 1980; Bloch and Gorski, 1988).

Brain size decreases after anti-androgen treatment observed in the above mentioned study where also very dramatic. Indeed, the magnitude of change signified a decrease in brain volume, which is at least ten times the average decrease observed a year in healthy adult individuals (Hulshoff Pol et al, 2006). The authors include that it was not surprising that the influences of sex hormones on the brain were not limited to the hypothalamus, but were also expressed as changes in total brain size. Estrogen and androgen receptor mRNA containing neurons are not limited to the hypothalamus, but are distributed throughout the adult human brain (Hulshoff Pol et al, 2006; Simerly et al, 1990).

Research has documented that American blacks possess androgen (e.g. Testosterone) levels that are as much as 10% higher than American whites (Ross and Henderson, 1994; Bernstein et al, 1986; Ross et al, 1995). This difference, as it is not excessive, should also offer blacks a number of genetic and health benefits. For example, testosterone level differences of this magnitude would suggest that blacks on average will have comparably larger brains than do whites. East Asians have been shown to possess much lower levels of androgens (Ross et al, 1995).

Notes:

1. Definition is from: University of Michigan comprehensive Cancer Center; Fertility & Cryopreservation Glossary.

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