Write a Review. Related Searches. Arthur Ashe.
Series by cover
Born in the segregated South in , Ashe overcame racial prejudices and segregation to break Born in the segregated South in , Ashe overcame racial prejudices and segregation to break into the world of tennis, which had traditionally been dominated by whites. He rose to the top of the sport, winning three Grand Slam trophies View Product. Ghanaian Literatures. Ghananian Literature is a scholarly and very valuable collection surveying the Ghanian literatures and their Ghananian Literature is a scholarly and very valuable collection surveying the Ghanian literatures and their critical reception until the present decade.
World Literature TodayGhana, one of the smaller countries in Africa, is a linguistically and culturally pluralistic society that has Profit of Education. This important book translates evidence and examines policy, proposing a plan to save America's schools Allen et al. Likewise, Ivanovic found in a study conducted in Chile with 96 students who were 18 years old that the average cc of men was 1, cm 3 after appropriate adjustments, while the capacity of women was on average 1, cm 3 Ivanovic et al. Studies using MRI have also observed these differences Gur et al.
Fat distorts the formula again.
A way to avoid this distortion is to consider the lean body mass. The deviation of the regression brain-to-lean-body-mass weight ratio allows for balancing the EQ of men and women. Thus, a man with a brain size of 1, In addition, the cc of the great physicist Albert Einstein was 1, cm 3 , considerably less than the average size for an adult Anderson and Harvey, The Einstein ratio was 1. Thus, more neurons were located in a smaller space. Besides, Simmons presented results showing two skulls with the same external measurement but with different cranial capacities.
He also presented the opposite results: two skulls with different external measurements with identical cranial capacities. In summary, the encephalization quotient formula — while allowing comparisons between the level of intelligence of animals, especially mammals — is not the most appropriate for comparison among humans since it does not consider factors that distort the formula, as presented above, and others, such as density of neurons, cortical thickness, number of nc , brain folding, and the evolution of cerebral cortex, that are very important and may correlate better with human intelligence.
In some cases, the effects may be irreversible and in others they may be only temporary. Eppig et al. An interesting study on early intellectual stimulation, which demonstrates the dramatic effect of the environment on intelligence when individuals belong to low socioeconomic levels, was led by Harold Skeels on 25 children who lived in an orphanage in the United States Skeels et al. The orphanage was crowded and understaffed, so 13 little girls, whose average age was 19 months, were transferred to the Glenwood State School for retarded adult woman.
The average IQ of these girls was 64, while the average IQ of the children who remained in the orphanage was After 18 months, the girls were transferred to a special school that provided the finest care, love, and attention from their teachers. They were tested again and the average IQ jumped to 93 points. Of the 13 girls, 11 were given up for adoption. Two years later, these 11 girls were evaluated again — this time their IQ increased to an average of points.
Meanwhile, the children who remained in the orphanage were tested again and their average IQ was 66 points an average decrease of 21 points. The fundamental difference between these two groups was the quality of life, the experience. While one group was properly stimulated and motivated, the other was treated as if its members were mentally retarded.
Another study conducted in France revealed that a group of children who were adopted when they were between 4 and 6 years of age had an average IQ of 77 — very close to mental retardation. Nine years later, these same children were retested. Contrary to popular belief that IQ is stable, their IQ increased. Those children who grew up in working class families or on the farm obtained an IQ of Again, the main difference between these three groups was the experience, the quality of life.
These examples show that genetics and environment cannot be evaluated as two separated spheres. Turkheimer et al. On the other hand, properly stimulated and motivated children when a new cognitive or motor skill is learned may be able to change the brain structure and its functional organization and surpass the genetic potential. Research shows that the structure of the adult human brain changes when a new cognitive or motor skill, including vocabulary, is learned Draganski et al. Particularly, an increase of gray matter is observed, what is known as neuroplasticity or cortical re-mapping.
The preponderance of evidence shows that absolute brain size, relative brain size, or the different regions of the brain, such as cerebral cortex, cortical thickness, frontal and parietal regions, or cerebellum, are all positively correlated with intelligence. Research also clearly notes that experience plays an indisputable role on the intellect of individuals. The fundamental study of key scientific findings seems to show that genotypes are responsible for defining the theoretical limits of intelligence, but experience environmental influence is largely responsible for determining whether those limits will be reached or exceeded.
The brain changes with practice. Everything indicates that experience makes the great difference, and therefore, we contend that the gene-environment interplay is what defines the IQ of an individual. The relationship between brain size or brain compartment size and intelligence is controversial. It is clear, as Detterman points out, without a forum for the resolution of controversy, controversy will not be resolved and science will not advance. There are many positive correlations between brain size and intelligence, but we all know that correlation does not demonstrate causation.
How are brain structure and genes mapped on behavior and intelligence? Many questions are yet to be answered, and numerous issues obviously require much further research. The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Allen, J. Normal neuroanatomical variation in the human brain: an MRI-volumetric study. Anderson, B. Alterations in cortical thickness and neural density in the frontal cortex of Albert Einstein. Andreasen, N. Intelligence and brain structure in normal individuals. Psychiatry , — Pubmed Abstract Pubmed Full Text. Barton, R. Olfactory evolution and behavioral ecology in primates. Beals, K. Brain size, cranial morphology, climate, and time machines. CrossRef Full Text. Bigler, E. Aging, brain size, and IQ. Intelligence 21, — Bouchard, T. Genetic influence on human psychological traits.
The cerebellum contributes to mental skills. Brand, C. Broca, P.
Sur le volume et la forme du cerveau suivant les individus et suivant les races. Paris 2, —, —, — Ceci, S. Darwin should scientists study race and IQ? YES: the scientific truth must be pursued. Nature , — Colom, R. Distributed brain sities for the g-factorof intelligence. Neuroimage 31, — Coon, C. Some problems of human variability and natural selection in climate and culture.
Deary, I. A Very Short Introduction. Oxford: Oxford University Press. Detterman, D. Editorial note on controversial papers. Intelligence 34, 1. Dickens, W. Black Americans reduce the racial IQ gap: evidence from standardization samples. Draganski, B. Neuroplasticity: changes in grey matter induced by training. Driemeyer, J. Changes in gray matter induced by learning-revisited. PLos ONE 3, e Egan, V. Eppig, C. Parasite prevalence and the worldwide distribution of cognitive ability.
Flynn, J. What is Intelligence? Cambridge: Cambridge University Press. Foley, R. Ecology and energetics of encephalization in hominid evolution. B Biol. Galton, F. On head growth in students at the University of Cambridge. Gaser, C. Brain structures differ between musicians and non-musicians.
When genes matter for intelligence - Gene Expression
Gibson, K. Evolution of human intelligence: the roles of brain size and mental construction. Brain Behav. Gould, S. The Mismeasure of Man. New York: Norton. Gur, R. Sex differences in brain gray and white matter in healthy young adults: correlations with cognitive performance. Haier, R. Structural brain variations and general intelligence.
- IQ and the Wealth of Nations - Marginal REVOLUTION;
- Numerical Methods in Finance: Bordeaux, June 2010?
- Deregulation in the European Union: Environmental Perspectives.
- Movement Disorders In Clinical Practice.
- Recommended for you.
- IQ and the Wealth of Nations (Human Evolution, Behavior, and Intelligence) | Trade Me Marketplace.
Neuroimage 23, — Harvey, I. Volumetric MRI measurements in bipolar compared with schizophrenics and healthy controls. Haug, H. Brain sizes, surfaces, and neuronal sizes of the cortex cerebri: a stereological investigation of man and his variability and a comparison with some mammals. Healy, S. A critique of comparative studies of brain size. B , — Herrnstein, R. Ho, K. Analysis of brain weight. Adult brain weight in relation to body height, weight, and surface area.
Hogan, M. Cerebellar brain volume accounts for variance in cognitive performance in older adults. Cortex 47 — Hooton, E. The American Criminal , Vol. Hunt, E. Considerations relating to the study of group differences in intelligence. Ivanovic, D. Head size and intelligence, learning, nutritional status and brain development. Head, IQ, learning, nutrition and brain. Neuropsychologia 42, — Brain development parameters and intelligence in chilean high school graduates.
Intelligence 32, — Iwaniuk, A. A comparative analysis of relative brain size in waterfowl Anseriformes. Jackson, J. Jaeggi, A. Improving fluid intelligence with training on working memory. Jensen, A. Psychometric g related to differences in head size. Westport, CT: Praeger Publishers.
Jerison, H. Evolution of the Brain and Intelligence. New York: Academic Press. Han, C. Jensen, and B. Dudek New York: Academic Press , 29— Animal intelligence as encephalization. Sternberg Cambridge: Cambridge University Press , — Jung, R. The parieto-frontal integration theory P-FIT of intelligence: converging neuroimaging evidence. Brain Sci. Jurgens, H. Lynn works out the genetic contribution in most detail for people of African descent. He argues that Blacks in the United States appear to have experienced broadly the same environment as Whites in regard to the environmental determinants of intelligence , such as nutrition, because Blacks and Whites have had the same average height since World War I.
He presents evidence that Blacks in the southern states have very little White ancestry and have an average IQ of about 80, and he proposes this be adopted as the genotypic IQ of Africans. Consequently, because the average IQ for Blacks in sub-Saharan Africa is about 67, he takes this point difference as the amount due to the adverse environmental conditions , principally poor nutrition , and health , found on that continent. They discuss how race differences in intelligence have evolved. This showed that during the course of evolution, species have evolved greater intelligence in order to survive in more cognitively demanding environments.
The same principle, Lynn argues, explains the evolution of race differences in human intelligence. As early humans migrated out of Africa they encountered the cognitively demanding problem of having to survive cold winters where there were no plant foods and they had to hunt, sometimes big game. They also had to solve the problem of keeping warm. This required greater intelligence than was needed in tropical and semi-tropical equatorial Africa where plant foods are plentiful throughout the year.
Lynn shows that race differences in brain size and intelligence are both closely associated with low winter temperatures in the regions they inhabit. He gives a figure of 1, cc for the average brain size of sub-Saharan Africans, as compared with 1, cc for Europeans and 1, cc for East Asians. My book provides many details of individual studies.
Moreover, magnetic resonance imaging studies make clear that the relation between brain size and intelligence is highly reliable. Lynn is on very safe ground in his statements here. From time to time Lynn notes anomalies in his theory that require explanations. One of these is that Europeans made most of the great intellectual discoveries, while the East Asians, despite having a higher IQ, made relatively few—a paradox extensively documented by Charles Murray in his book, Human Accomplishment.
Lynn proposes an explanation for this: it may be that East Asians are more conformist than Europeans and this inhibits creative achievement. In Race, Evolution, and Behavior , I presented evidence that this personality trait has genetic roots.
Another anomaly: the average IQ of Israel is only about 95—substantially higher than the median IQ of 85 found elsewhere in the region, but much lower than the average IQ of Jews outside of Israel , estimated at between and Lynn suggests these differences could have arisen from selective migration more intelligent Jews emigrated to Britain and the USA , intermarriage with different IQ populations those in Europe versus those in North Africa , selective survival through persecution European Jews were the most persecuted , and the inclusion of ethnic non-Jews among the Ashkenazim in Israel as a result of the immigration of people from the former Soviet Bloc countries who posed as Jews.