In 1973 while 11.1 per cent of the United States population was black, about a quarter of all major league baseball players, a third of all pro football players and two thirds of all pro basketball players were black. Black players also appeared to earn more than white players in these sports, which would suggest a superior athlete. In more recent years it has been shown that while African Americans make up approximately 12.5% of the American population, they comprise nearly 79 per cent of pro Basketball players, close 67 per cent of pro football players and are dramatically overrepresented among professional boxing champions and other professional athletes.

By Bernie Douglas (June 3, 2008), Revised February 17, 2009

The Intelligence of Athletes:

Professional athletes and especially those involved in team sports must operate within highly dynamic and multi-dimensional situational contexts (Vickers, 2007) requiring a very complex set of cognitive skills (see Kioumourtzoglou et al, 1998; Horgan and Tienson, 1992). Often these skills resemble, or share close relationships with the kinds of skills that, in the not so distant past, helped to make our ancestors successful hunters and gathers. Hunting is assumed to have been in practice for 99% of human prehistory. So that “intelligence” in the past was never a measure of one’s academic aptitude or potential for formal schooling, but was instead a measure of one’s potential for real life survival, while this largely depended on hunting and gathering. This kind of survival also depended on the same intellectual abilities as those employed by athletes during competition. Formal schooling of the kind familiar to most in the West today did not become a part of most people’s lives until the early 20th century.
Even today in many parts of the world, formal schooling of the kind enjoyed by western children may, in fact, be entirely inaccessible. This is because in some parts of the world an education can be more of a privilege than an expectation (particularly for girls). Therefore, the best measures of intelligence should be those generally unrelated to literary pencil and paper multiple-choice tasks. Skills like quick decision making, cooperativeness, orienting efficacy, the capacity to represent features on a vast scale, and short-term strategic considerations of the kind used by Basketball players, for example (Huciński et al, 2007; Horgan and Tienson, 1992), are instead better or more universal indicators of intelligence, as they were likely very important to the survival of our early hunter-gatherer ancestors. What’s more, these skills are also highly relevant even within today’s modern social and business environments.

Athletes must be able to make split-second decisions under the pressures of competition (Vickers, 2007). Hundreds of times in the course of a basketball game, for instance, a player is faced with a decision that must be made rapidly, to shoot or pass, for example, and if to pass, to which teammate. The player has to take in a complex, rapidly changing situation, and doing this requires a highly specialized and practiced kind of perceptual processing (Huciński et al, 2007; Apostolidis et al 2004; Wyżnikiewicz-Kopp, 1977;Horgan and Tienson, 1992). There is a large amount of propositional information the players must apply to the scene to appropriately “take in” the situation.  Some players are better at recognizing situations than others. Thus, players with similar physical abilities do not always respond in physically or behaviorally similar ways to similar situations, because their cognitive abilities and responses are different (Huciński et al, 2007; Horgan and Tienson, 1992). In view of the diversity and variability of motor stimuli, basketball demands particular cognitive abilities to be able to adjust one’s internal states to diverse situations, or to think tactically (Huciński et al, 2007). A player can do many different things in a given situation, depending upon his current aims. A player's physical skills plus his understanding of the present court configuration are not sufficient to determine his action. Short-term strategic considerations figure importantly in determining a player's actions.

Besides decision making and perceptual skills there are also the basic properties that structure the game. For example, who is in the game? Of those in the game, who is a teammate and who is an opponent? This information is not literally contained in a perceptual or image-like representation of the situation. There are also more global properties of the game, such as the score, the time left on the time clock, the time left in the game, the coach's game plan and/or latest instructions, and what defense the opposition is playing. Second, there are specific properties of individual players: height, jumping ability, speed, shooting ability, and so forth. Third, there are more transient properties: who is guarding whom, what position each player is playing, who is having a good game and who isn't, who is shooting well, who is in foul trouble, etc.

Formal Studies of Cognitive Ability in Athletes:

Literature on covert orienting in various athlete groups points to four general findings. First, effects of voluntary covert orienting are usually smaller in magnitude for highly skilled athletes than for less skilled athletes or nonathletes, and this has been given a variety of interpretations, including that athletes are able to distribute their attention more effectively over multiple locations (Nougier et al., 1991; Nougier et al., 1989). Eric et al (2006) preformed two experiments investigating the perceptual processes employed during same/different judgment tasks in professional athletes and novice athletes. It was found that the eye movements of experts (i.e., number of fixations and fixation duration) were “consistent” across discrepant source and target conditions where the number of displaced elements was manipulated. In contrast, novices “decreased” the number of fixations employed as the number of elements displaced increased. Manipulation of target presentation confirmed that recognition was viewpoint dependent for both expert and novice players. The degradation in performance was accompanied by a change in the visual search behaviors employed by experts, which confirmed the strength of the search–cognition–performance links (Ibid).

Kioumourtzoglou et al (1998) conducted a laboratory study with a group of 13 men on an elite male national team of basketball players, between the ages of 22 and 23 years; and a control group of 15 men of equal age (physical education class) to assess differences in their scores on cognitive skills (memory-retention, memory-grouping analytic ability), perceptual skills (speed of perception, prediction, selective attention, response selection), and motor skills (dynamic balance, whole body coordination, wrist-finger dexterity, rhythmic ability). Their analysis showed that elite male basketball players scored higher on hand coordination and lower on dynamic balance given their anthropometric measurements (mainly height). Elite players were better on memory-retention, selective attention, and on prediction measures than the control group. The above skills are important in basketball performance (ibid).

In 1973 while 11.1 per cent of the United States population was black, about a quarter of all major league baseball players, a third of all pro football players and two thirds of all pro basketball players were black (Scully, 1973). Black players also appeared to earn more than white players in these sports (ibid), which would suggest a superior athlete. In more recent years it has been shown that while African Americans make up approximately 12.5% of the American population, they comprise nearly 79 per cent of pro Basketball players, close 67 per cent of pro football players and are dramatically overrepresented among professional boxing champions and other professional athletes.

Studies of reaction time in athletes and non athletes generally find athletes to out perform non athletes in these tasks. Reaction time is believed to be a good indicator of performance in sports according to one study (Kaur et al, 2006). This may also partially explain why Blacks athletes tend to be found overrepresented in many of the world’s most highly selective high performance sports (e.g. Football and Basketball and Box). Kaur et al (2006), found quicker reaction times in athletes as compared to control groups. Kamin (1995) reported that in tasks of reaction time, blacks in 2 out of three studies out performed white individuals.

Bredin et al (2005), in an experiment of cognitive ability in athletes and non athletes, examined subjects’ ability to walk when blindfolded to a previously seen target.  In the two groups of healthy volunteers: 21 athletes and 20 non-athletes. Subjects were asked to walk at three different velocities (slow, normal, and fast) to a target (10 m in front of them) that they had seen before being blindfolded. Increase in velocity was associated with a decrease in the distance walked for both groups. Both groups were accurate at normal velocities; however, athletes were also accurate at fast velocities whereas non-athletes undershot the target.

The Testosterone Factor:

Testosterone is the Primary male hormone and is responsible for the development of secondary sexual characteristics. Low testosterone levels in males has 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). Research shows that black men possess androgen levels (e.g. testosterone levels) that are superior to American whites (Ross and Henderson, 1994; Bernstein et al, 1986; Ross et al, 1995) – levels about 10% higher.

High testosterone levels have been associated with improved health and longevity, superior motor abilities, increased reproductive success (in men), increased mental focus (sharpens focus and concentration), larger brain volume, and “boldness” (Dabbs and Dabbs, 2000; Solms and Turnbull, 2002; Hulshoff Pol et al, 2006; Fink el al, 2005). Research shows also that low testosterone males tend to have higher pitched voices and are less dominant in appearance (Fink el al, 2005; Dabbs and Dabbs, 2000). Vegetarians have also been found to have lower androgen levels than do those who eat meat (Dabbs and Dabbs, 2000), as have castrated males (King A. et al, 2001). Androgen Levels are found to be higher in professional athletes.

Psychomotor:  Skills and Development

Studies find that black infants demonstrate superior psychomotor development when compared with white infants (Super, 1976; Wilson 1978). This may be interpreted as being indicative of superior neurological development, as delayed psychomotor development can be associated with developmental defects. For example, Walter et al (1989) found that infants with Iron Deficiency Anemia tended to do poorly on body balance-coordination skills when compared with controls. While Autti-Rämö and Granström (1991) found that infants exposed to intrauterine alcohol experienced delayed psychomotor development.

Psychomotor vigilance performance is said to be important to athletic performance. A national survey on the psychomotor development of children under 6 years of age was carried out with the help of 129 pediatricians in Argentina. Analysis was applied to a sample of 3573 healthy, normal children in order to estimate selected percentiles (25th, 50th, 75th and 90th). Multiple logistic regressions showed that social class, maternal education and sex (female) were associated with earlier attainment of some selected developmental items, achieved at ages later than 1 year. This research suggests that black infants may acquire psychomotor skills that are at levels superior even to white infants from advantaged backgrounds as black infants have consistently shown greater acquisition of such skills (Wilson, 1978). Studies investigating motor development have also found that black boys are also superior to white children in general motor abilities at later ages (Wilson 1978; DiNucci, 1975).  


Molecular genetic studies show that people of African descent generally possess higher levels of genetic variation and heterozygosity than do people of other backgrounds (Vigilant et al. 1991; Nei et al. 1993; Cavalli-Sforza et al. 1991; Deka et al. 1995b; Jorde et al. 1997; Lohmueller et al, 2008). Heterozygosity is thought to enhance resistance of hosts to infectious diseases, offers a greater degree of fitness for one or the other allele, and improves overall health (Gangestad & Buss 1993, Thornhill & Gangestad 1993). This may explain some of the difference observed in motor development between black and white children at younger ages. Africans have also been shown to possess the largest total number of alleles, as well as the largest number of unique alleles for most systems (Jorde et al, 2000). Surveys of 2000 databaseascertained insertion/deletion polymorphisms also show a pattern of higher ancestral allele frequencies in African populations (Weber et al. 2002). These genetic advantages, along with long hours of practice and dedication may contribute to the observed superior performance among black athletes in a number of the world’s most highly selective athletic arenas.

Athletics, Eye Color, and Visual Acuity:

Researchers continue to examine the distinctiveness of motor performance by dark- versus light-eyed individuals. For example, it has been shown that Dark-eyed individuals generally perform better at reactive type tasks, while light-eyed individuals perform better at ‘some’ self-paced tasks (Miller et al, 1992; Beer and Fleming, 1988; Rowe and Evans, 1994; Beer and Beer, 1989). Strange as this research may seem, Beer and Fleming (1988) using multiple regression analysis found that dark-eyed students hit a target with a frisbee more times than did light-eyed students. While Rowe and Evans (1994) had College students (61 men, 64 women) perform a forehand rally with different colored racquetballs. Eye color, sex, and total hits were recorded for each subject. Men scored significantly better with balls of each color than did women. Dark-eyed men performed better than other subjects and performance was better with blue balls than yellow or green balls. Other research shows that children with blues eyes tend also to be more timid and socially un savvy in preschool when compared with children of darker eye color  (Moehler et al, 2006; Coplan et al, 1998), and are more susceptible to alcohol abuse at later ages (Bassett and Dabbs, 2001).
Other cognitive studies argue the following: athletes possess superior visual abilities to nonathletes; elite athletes possess visual abilities superior to those of ordinary athletes; and, athletes, in particular those participating in fast paced sports involving resolution of detail at high speed, might have innately superior DVA (dynamic visual acuity) or might have developed superiority through repeated practice (Blundel, 1985; Ishigaki and Miyao; Long and Riggs, 1991; Bahill and La Ritz, 1984).
Blacks in one longitudinal study were found to have superior visual acuity to all other ethnic groups. African Americans (6.6%) were shown to have slightly higher rates of myopia (near sightedness) to, but not significantly different from white Americans (4.4%), while Asians were shown have the highest prevalences (18.5%), followed by Hispanics (13.2%) (Kleinstein et al, 2005). For hyperopia (far sightedness), whites had the highest prevalences (19.3%), followed by Hispanics (12.7%). Asians were shown to have the lowest prevalences of hyperopia (6.3%) and were not significantly different from African Americans (6.4%). For astigmatism, Asians and Hispanics had the highest prevalences (33.6% and 36.9%, respectively) and did not differ from each other. African Americans had the lowest prevalence of astigmatism (20.0%), followed by whites (26.4%) (Kleinstein et al, 2005). This suggests that with respect to general visual acuity blacks may have a strong advantage relative to other groups.

Pineal Gland: A Potential Cognitive Advantage for Africans  

Racial differences have been noted in the rate of pineal calcification as seen in plain skull radiographs. In Caucasians, according to studies, calcified pineal is visualized in about 50% of adult skull radiographs after the age of 40 years (Wurtman et al, 1964); while others argue that Caucasians, in general, may suffer from rates of pineal gland calcification at rates as high as 60-80% (King, 2001). Murphy (1968) reported a radiological pineal calcification rate of 2% from Uganda, while Daramola and Olowu (1972) in Lagos, Nigeria found a rate of 5%. Adeloye and Felson (1974) found that calcified pineal was twice as common in White Americans as in Blacks in the same city, strengthening a suspicion that there may be a true ethnic differences with respect to this apparatus. In India a frequency of 13.6% was found (Pande et al, 1984). Calcified pineal gland is a common finding in plain skull radiographs and its value in identifying the midline is still complementary to modern neuroradiological imaging.

There is a surprising rarity of calcified pineal gland on skull roentgenograms in West Africans (Akano and Bickler, 2003; Adeloye and Odeku, 1967). Adeloye and Odeku (1967) working from a hospital where an average of about 2,000 skull roentgenographic examinations were done every year, encountered less than 10 cases of roentgenologically visible calcified pineal gland in the Neurosurgery unit during a period of 10 years. In the tasks of daily life, calcification in the pineal gland affects our brain's ability to function. Calcification of the pineal gland is shown to be closely related to defective sense of direction (Bayliss et al, 1985). In a tricentre prospective study of 750 patients lateral skull radiographs showed that 394 had calcified pineal glands. Sense of direction was assessed by subjective questioning and objective testing and the results noted on a scale of 0-10 (where 10 equals perfect sense of direction). The average score for the 394 patients with pineal gland calcification was 3.7 (range 0-8), whereas the 356 patients without pineal gland calcification had an average score of 7.6 (range 2-10). This difference was highly significant (p less than 0.01) (Bayliss et al, 1985). Also, the effects of disturbed sleep and memory are well documented.

The Pineal Gland looks like a miniature pine cone and is situated in the middle of the brain beneath the two brain halves, surrounded by the ventricles, under the roof of the corpus callosum (cross-beam connecting the 2 brain halves). This active organ has, together with the Pituitary Gland, the next highest blood circulation after the kidneys. The pineal gland is responsible for the production of melatonin, a hormone that is secreted in response to darkness, and is also the site in the brain where the highest levels of Serotonin can be found (Sun et al, 2001). In the pineal, 5-HT (Serotonin) concentration displays a remarkable diurnal pattern, with day levels much higher than night levels. Serotonin plays an important role in sleep, perception, memory, cardiovascular activity, respiratory activity, motor output, sensory and neuroendocrine function. Research has shown that alterations in neurotransmitters such as serotonin are associated with the risk for suicide. Interestingly 72% percent of all suicides and 79% of all firearm suicides are committed by white men.

What is the Pineal Gland’s Function?

One study has shown a reciprocal relationship between the pineal and pituitary gland so that if the pineal is impaired, it affects the pituitary (Karasek and Reiter, 1982). This has a whole cascade of effects on the other glands and hormone production. The pituitary gland is an endocrine gland located at the base of the brain, and produces hormones, such as growth hormone, luteinizing hormone, follicle stimulating hormone and thyroid stimulating hormone.

Pineal indolamine (e.g. Melatonin/Serotonin) and peptide hormones influence immune functions. Melatonin, in particular, increases immune memory while T-dependent antigene immunization stimulates antibody production. According to Maestroni (1993), in an article published in the Journal of Pineal Research a tight physiological link between the pineal gland and the immune system is emerging that might reflect the evolutionary connection between self-recognition and reproduction. He goes further, mentioning that Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin appears to have an immunoenhancing effect. An interesting observation is the apparent protection from and rarity of autoimmune diseases in areas of West Africa (Greenwood, 1968) where pineal calcification is especially rare (Akano and Bickler, 2003; Adeloye and Odeku, 1967).

Scholars believe the reduction in melatonin with age may be contributory to aging and the onset of age-related diseases. This theory is based on the observation that melatonin is the most potent hydroxyl radical scavenger thus far discovered (Reiter, 1995). Prominent theories of aging attributes the rate of aging to accumulated free radical damage (Proctor, 1989; Reiter, 1995), and as Caucasians have higher rates of pineal calcification, which produces melatonin which is a vital free radical scavenger, some suspect that people of European descent may actually age faster than those from other continents. In fact, there have been studies that show Caucasians to wrinkle more severely and earlier than African Americans; the mean fraction of the face area covered with wrinkles is significantly smaller in African Americans than in Caucasians (Hillebrand et al, 2001). Caucasians also have significantly less well hydrated skin than African Americans (ibid).

Pineal gland calcification has also been implicated in the onset of Multiple sclerosis. Multiple Sclerosis is an autoimmune disease that affects the central nervous system (CNS). The CNS consists of the brain, spinal cord, and the optic nerves. Neuroradiological research has shown the pineal gland to be involved in the pathophysiology of Multiple Sclerosis. In a 1991 study by Sandyk R, and Awerbuch G.I published in the International Journal of Neuroscience, it was shown that Pineal Calcification was found in 100% of MS patients! The strikingly high prevalence of pineal calcification in Multiple sclerosis provides indirect support for an association between MS and abnormalities of the pineal gland (Sandyk and Awerbuch, 1991). Multiple Sclerosis tends to affect Caucasians disproportionately, is nearly unheard of in Africa and is rare among African Americans (Modi et al, 2001; Foster, 1970; Kurtzke et al, 1979). A high prevalence of pineal calcification has also been linked to bipolar disorder.

Caucasians have also been shown to suffer disproportionately from a whole array of different neurodegenerative disorders. For example, Huntington’s disease, optic neuritis, Parkinson’s disease, Multiple Sclerosis, PKU (Phenylketonuria), Anencephaly and Spinal bifida are all found in much higher frequencies among people of European decent than other groups (Bates et al, 2002; Okano et al, 1990; Tanner et al, 1996; Nelson et al, 1997; Modi et at, 2001; Kurtzke, 1979; Alan, 2003).


Adeloye, A., and Odeku, E. L (1972). Preliminary study of pineal gland in Nigerian African. Rev.neuro-psiquiat.,1972, I, 54-77

Adeloye D., Felson B. (1974). Incidence of normal pineal gland calcification in skull roentgenograms of black and white Americans. American Journal of Roentgenology VOL. 122, No. 3.

Akano A.; Bickler S.W. (2003). Pineal Gland Calcification in Sub-Saharan Africa Clinical Radiology, Volume 58, Number 4, April 2003 , pp. 336-337(2)

Alan H. Goodman , Deborah Heath , M. Susan Lindee et al (2003).Genetic Nature/Culture Anthropology and Science beyond the Two-Culture Divide (see Chapter 13 p 268).  UNIVERSITY OF CALIFORNIA PRESS

Bahill AT, La Ritz T. (1984). Why can't batters keep their eyes on the ball? American Scientist, Volume 72, Issue 3, p.249-253.

Bassett J.F. and Dabbs Jr J.M. (2001). Eye color predicts alcohol use in two archival samples. Personality and Individual Differences Volume 31, Issue 4, 5 September 2001, Pages 535-539

Bates G, Harper P, Jones L (2002) Huntington's Disease 3rd edition. Oxford University Press, New York

Bayliss CR, Bishop NL, Fowler RC (1985). Pineal gland calcification and defective sense of direction. Br Med J (Clin Res Ed). 1985 Dec 21-28;291(6511):1758-9.

Beer J, Beer J. (1989). Relationship of eye color to winning horseshoe pitching contests. Percept Mot Skills. 1989 Feb;68(1):136-8.

Beer J, Fleming P. (1988). Effects of eye color on frisbee toss. Percept Mot Skills. 1988 Apr;66(2):675-6.

Bernstein L, Ross RK, Judd H, et al (1986). Serum testosterone levels in young black and white men. J Natl Cancer Inst 76:45—48, 1986.

Blundell NL. (1985). The contribution of vision to the learning and performance of sports skills: Part 1: The role of selected visual parameters. The Australian Journal of Science and Medicine in Sport September 1985 249-253.

Bredin J.,  Kerlirzin Y., Israël I. (2005) . Path integration: is there a difference between athletes and non-athletes? Experimental Brain Research Volume 167, Number 4 / December, 2005.

Cavalli-Sforza LL, Bowcock AM, Kidd JR, Mountain JL, Hebert JM, Carotenuto L, Kidd KK, (1991) Drift, admixture, and selection in human evolution: a study with DNA polymorphisms.  Proc Natl Acad Sci USA 88:839–843.

Coplan RJ, Coleman B, Rubin KH (1998). Shyness and little boy blue: iris pigmentation, gender, and social wariness in preschoolers. Dev Psychobiol. 1998 Jan;32(1):37-44.

Dabbs,J.M, Dabbs M.G. (2000). Heroes, Rogues and Lovers: Testosterone and Behavior. McGraw-Hill Companies (July 25, 2000).

Daramola, G. F., and Olowu, A. 0. (1972). Physiological and radiological implications of low incidence of pineal calcification in Nigeria. Neuroendocrinology, 1972, 9, 41-57.

Deka R, Jin L, Shriver MD, Yu LM, DeCroo S, Hundrieser J, Bunker CH, et al (1995a) Population genetics of dinucleotide (dC-dA)n.(dG-dT)n polymorphisms in world populations. Am J Hum Genet 56:461–474.

DiNucci, James M. (1975). Motor Performance Age and Race Differences between Black and Caucasian Boys Six to Nine Years of Age. The ERIC database, an initiative of the U.S. Department of Education. 1975-02-00.

Eric L., Paul W., Mark W., Hubert R. (2006). Expertise in basketball modifies perceptual discrimination abilities, underlying cognitive processes, and visual behaviours.  Visual Cognition, Volume 13, Number 2, Number 2/January 2006, pp. 247-271(25).

Evans JR. (2003). Risk factors for age-related macular degeneration. Prog Retin Eye Res 2001;20:227–53.

Fink B., Grammer K., Mitteroecker P., Gunz P., Schaefer K.,. Bookstein F.L. and Manning J.T. (2005). Second to fourth digit ratio and face shape Proc. R. Soc. B (2005) 272, 1995–2001.

Gangestad SW, Buss DM. 1993. Pathogen prevalence and human mate preferences. Ethol. Sociobiol. 14:89–96.

Greenwood BM. Autoimmune disease and parasitic infections in Nigerians. Lancet 1968;i:380-2.
Harrison GA. 1992. Human genetics and variation. In: Harrison GA, Tanner JM, Pilbeam DR, Baker PT, editors. Human biology. Oxford: Oxford University Press. p 145–336.

Herlin S.J. (2003). Ancient African Civilizations to ca. 1500. Text Supplement and Study Guide for History/PAS 393.

Hulshoff Pol H.E., Cohen-Kettenis P.T., Peper J.S., Cahn W. (2006). Changing your sex changes your brain: influences of testosterone and estrogen on adult human brain structure. European Journal of Endocrinology (2006) 155 S107–S114.

Horgan, T. and Tienson, J. (1992). Cognition needs Syntax but not rules. Midwest Studies in Philosophy 15, 256-79.

Ishigaki H, Miyao M. (1994). Implications for dynamic visual acuity with changes in age and sex. Perceptual and Motor Skills 1994. 78 363-369.

Jorde LB, Rogers AR, Bamshad M, Watkins WS, Krakowiak P, Sung S, Kere J, et al (1997). Microsatellite diversity and the demographic history of modern humans. Proc Natl Acad Sci USA 94:3100–3103.

Jorde, L.B., Watkins, W.S., Bamshad, M.J., Dixon, M.E., Ricker, C.E., Seielstad, M.T., and Batzer, M.A. (2000). The distribution of human genetic diversity: Acomparison of mitochondrial, autosomal, and Y-chromosome data. Am. J. Hum. Genet. 66: 979–988.

Kamin L.J. (1995). Lies, Damn lies and Statistics.

Karasek M, Reiter RJ (1982). A reciprocal relationship between the adenohypophysis and the pineal gland. Med Hypotheses. 1982 Jul;9(1): 1-9.

King A., , Ashby J. and Nelson C. (2001). Effects of Testosterone Replacement on a Male Professional Singer. Journal of Voice Volume 15, Issue 4, December 2001, Pages 553-557.

Kioumourtzoglou E, Derri V, Tzetzis G, Theodorakis Y. (1998). Cognitive, perceptual, and motor abilities in skilled basketball performance. Percept Mot Skills. 1998 Jun; 86 (3 Pt 1):771-86.

Kleinstein R.N,; Jones L.A, Hullett S., Kwon S,  Lee R.J., Friedman N.E., Manny R.E., Mutti D.O, et al (2003). Refractive Error and Ethnicity in Children. ARCH OPHTHALMOL/VOL 121, AUG 2003.

Kuar P. Paul M., Sandhu J.S. (2006) Auditory and visual reaction time in athletes, healthy controls, and patients of type 1 diabetes mellitus: A comparative study. Int J Diab Dev Ctries, Sept 2006, Vol 26, issue 3.

Kunz D, Schmitz S, Mahlberg R, Mohr A, Stoter C, Wolf KJ, Herrmann WM. (1999) A new concept for melatonin deficit: on pineal calcification and melatonin excretion. Neuropsychopharmacology. 1999 Dec;21(6):765-72.

Kurtzke JF, Beebe GW, Norman JE Jr. (1979). Epidemiology of multiple sclerosis in U.S. veterans: 1. Race, sex, and geographic distribution. Neurology 1979;29:1228–1235.

Lohmueller KE, Indap AR, Schmidt S, Boyko AR, Hernandez RD, Hubisz MJ, Sninsky JJ, White TJ, Sunyaev SR, Nielsen R, Clark AG, Bustamante CD (2008). Proportionally more deleterious genetic variation in European than in African populations. NATURE, Vol 451, 21 February 2008.

Long GM, Riggs CA. (1991) Training effects on dynamic visual acuity with free-head viewing. Perception 1991 20 363-371.

Maestroni GJ (1993). The immunoneuroendocrine role of melatonin. J Pineal Res. 1993 Jan;14(1):1-10.

McLachlan R. and Allan C. (2005). Testosterone Deficiency fact sheet. Andrology Australia, funded by the Australian Government Department of Health and Ageing.

Miller LK, Rowe PJ, Lund J. (1992). Correlation of eye color on self-paced and reactive motor performance. Personality and Individual Differences Volume 31, Issue 4, 5 September 2001, Pages 535-539.

Modi G, Mochan A, Modi M, Saffer D. (2001). Demyelinating disorder of the central nervous system occurring in black South Africans. J Neurol Neurosurg Psychiatry 2001;70:500–505.

Moehler E., Kagan J., Brunner R., Wiebel A., Kaufmann C. and Resch F. (2006). Association of behavioral inhibition with hair pigmentation in a European sample. Biological Psychology Volume 72, Issue 3, June 2006, Pages 344-346.

Murphy, N. B. (1968). Carotid cerebral angiography in Uganda: review of boo consecutive cases. East African M. 7.,1968,45, 47-60.

Nei M, Livshits G (1990) Evolutionary relationships of Europeans, Asians, and Africans at the molecular level. In: Takahata N, Crow JF (eds) Population biology of genes and molecules. Baifukan, Tokyo, pp 251–265.

Nelson L, et al. (1997). Incidence of idiopathic Parkinson's disease (PD) in a health maintenance organization (HMO): Variations by age, gender, and race/ethnicity. Neurology 1997:A334.

Nougier, Vincent; Ripoll, Hubert; Stein, Jean-François (1989). Orienting of attention with highly skilled athletes. International Journal of Sport Psychology. 1989 Jul-Sep Vol 20(3) 205-223.

Nougier, Vincent; Stein, Jean-François; Bonnel, Anne-Marie (1991). Information processing in sport and "orienting of attention." International Journal of Sport Psychology. 1991 Jul-Dec Vol 22(3-4) 307-327.

Odeku, E.I., and Janota, I. (1967). Intracranial masses- Ibadan. West African M.F., 1967, 16, 31-42.

Okano Y.,  Eisensmith R.C., Dasovich M., Wang T., Güttler F., and Woo S. L. C. (1990). A prevalent missense mutation in Northern Europe associated with hyperphenylalaninaemia. European Journal of Pediatrics Volume 150, Number 5 / March, 1991 p. 347-352.

Persad, S., Menon, I. A. & Haberman, H. F. (1983) Photochem. Photobiol. 37, 63–68.
Proctor P.H. (1989). Free Radicals and Human Disease.  CRC Handbook of Free Radicals and Antioxidants, vol 1 (1989), p209-221.

Reed D.H., Frankham R. (2003). Correlation between Fitness and Genetic Diversity. Conservation Biology, Volume 17, Number 1, February 2003, pp. 230-237(8).

Reiter RJ. (1995): The pineal gland and melatonin in relation to aging: a summary of the theories and of the data Exp Gerontol. 1995 May-Aug;30(3-4):199-212.

Ross, R.K., Coetzee, G. A., Reichardt, J., Skinner, E, and Henderson, B.E. (1995). Does the Racial-Ethnic Variation in Prostate Cancer Risk Have a Hormonal Basis? Cancer, Volume 75, Issue S7 (p 1778-1782).

Ross R.K., Henderson B.E. (1994). Do diet and androgens alter prostate cancer risk via a common etiologic pathway? / Natl Cancer lnst 1994; 86:252-4.

Rowe PJ, Evans P. (1994). Ball color, eye color, and a reactive motor skill. Percept Mot Skills. 1994 Aug;79(1 Pt 2):671-4.

Sandyk R, Awerbuch G.I. The Pineal Gland in Multiple Sclerosis. International Journal of Neuroscience 1991; 61: 61

Scheib J.E., Gangestad S.W., and Thornhill R. (1999). Facial attractiveness, symmetry and cues of good genes. Proc. R. Soc. Land. B (1999) 266, 1913-1917.

Scully G.W. (1973). Economic Discrimination in Professional Sports Law and Contemporary Problems, Vol. 38, No. 1, Athletics (Winter - Spring, 1973), pp. 67-84 This article consists of 18 page(s).

Solms M. and, Turnbull O. (2002). The brain and the inner world. Other Press, New York

Sun X., Deng J., Liu T., and Borjigin J. (2001). Circadian 5-HT production regulated by adrenergic signaling. PNAS April 2, 2002 vol. 99 no. 7 4686–4691.

Super, C. M. (1976). Environmental effects on motor development: The case of African infant precocity. Developmental Medicine and Child Neurology, 18, 561–567.

Tanner C, Goldman S. (1996). Epidemiology of Parkinson's disease. Neurol Clin 1996; 14: 317-335.

Thornhill R, Gangestad SW (1993). Human facial beauty—averageness, symmetry, and parasite resistance. Hum. Nat. Interdiscip. Biosoc. Perspect. 4:237–69

Vickers J. (2007). Perception, Cognition, and Decision Training - The Quiet Eye in Action. Human Kinetics. Publishers; 1 edition (July 30, 2007).

Vigilant L, Stoneking M, Harpending H, Hawkes K, Wilson AC (1991) African populations and the evolution of human mitochondrial DNA. Science 253:1503–1507.

Watkins, W.S, Pradipta K. Das, Mark A. Batzer and Lynn B. JordeE. Brassington, Marion L. Carroll, Son V. Nguyen, Jerilyn A. Walker, B.V. Ravi Prasad, P. Govinda Reddy, Alan R. Rogers, Christopher T. (2003). Genetic Variation Among World Populations: Inferences From 100 Alu Insertion Polymorphisms. Genome Res. 13:1607-1618, 2003.

Weber, J.L., David, D., Heil, J., Fan, Y., Zhao, C., and Marth, G. (2002). Human diallelic insertion/deletion polymorphisms. Am. J. Hum. Genet. 71: 854–862.

Wilson A. (1978). Developmental Psychology of the Black Child. Africana Research Publications (December 1978).

Wiswell TE, Tuttle DJ, Northam RS, Simonds GR (1990).  Major congenital neurologic malformations. A 17-year survey. Am J Dis Child. 1990, 144:61-67

Wurtman, R. J., Axelrod, J., and Barchas, J. D (1964). Age and enzyme activity in human pineal. Letter to the editor. 7. C/in. Endocrinol. & Metabol., 1964,24, 299-301.