verder staat er dat omvang van hersenen word bepaals door het klimaat waarin je leeft. Ze beweren nu dat dat dus los staat van Ras. Ik heb eeb verassing voor je.
Verruit de meeste afrikanen wonen in een warm land of heeft dat eeuwen gedaan. Duhh
wat zij zeggen is dat als een n*ger was doorgetrokken naar het zuiden en n*ger was gebleven was zijn schedel niet veranderd.
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Ja dat klopt en ik beweer ok niet het tegendeel. Maar zeg nu eens duidelijk wat je dus concludeert uit dat onderzoek. Want het is echt niet duidelijk.
Ik zal kort samenvatten wat je zegt en dan moet je maar zeggen of ik het goed begrepen heb. De hersenomvang van de mens hangt af van het klimaat waar je leeft. Afrikanen, hadden ze in Afrika blijven leven, dan was hun hersenomvang gelijk gebleven.
MAAR ER IS GEEN BEWIJS DAT ER EEN RELATIE BESTAAT TUSSEN INTELLIGENTIE EN HERSENOMVANG;
tENVENS POSTE JE ERGENS ANDERS DAT OOK DE ONTDEKKINGSTOCHTEN DE HERSENOMVANG BEINVLOEDDE;
Je moet wikipedia ook goed lezen he: er staat dat de hersenschedel vooral vorm veranderde.
Lees het onderzoek van 2005 die een algemene analyse heeft gemaakt. Ik heb het reeds gepost. Er staat in het engels zoiets als: er is tot op heden geen enkel bewijs dat er een link bestaat tussen hersenomvang, ras en intelligentie.
Lees het discussion punt eens op wikipedia.
There's been more than enough research in this area.
And the research has been mostly inconclusive to determine whether any "racial" order exists for brain size.--Ramdrake 15:18, 8
October 2006 (UTC)
Then, please consider Beals et al., 1984 who studied over 10,000 skulls and found no racial ordering whatsoever.--Ramdrake 15:18, 8 October 2006 (UTC)
But normal variance within the species is nearly two-fold (from about 1000 to nearly 2000 cc). Thus the effects of a "racial" difference of less than a hundred cc can legitimately be questioned.--Ramdrake 15:18, 8 October 2006 (UTC)
The measured amount of genetic variation in the entire human population is extremely small; genetically we are very similar. Indeed, 93% of all genetic variability occurs within Africa; the human groups with the greatest difference between them occur in Africa. Research has also found that the differences between chimpanzees and humans exceed 69%, whereas the widest range between any two groups of humans is less than 3%. All of this calls the concept of biological races into serious question.
Given the current knowledge about genetics claims like these are disputable. A 0.5% difference could in theory already express itself in a twice as large penis, or better brain.
Possible, however the odds are heavily against it, until a gene (or subset of genes) is found which is tied in a known way to intelligence and also shows a pattern of differential "racial" distribution. Such gene or set of genes has not been found, although some vague candidates have been proposed.--Ramdrake 15:18, 8 October 2006 (UTC)
I believe we've been over this before: If we are to say that "brain size varies according to race", we should present the counter-argument brought by Beals et al (1984) and reviewed among others by Lieberman (2001) that this variation has nothing to do with race, which Lieberman shows is a view shared by many researchers in the field. This counter-argument rightfully belongs side by side with the original statement, otherwise we will end up putting more weight on the statement than on the counter-argument.--Ramdrake 20:59, 8 October 2006 (UTC)
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en nog een interessante tekst die iets zegt over de intelligentietesten:
Box D. Brain Size and Intelligence
The fact that so much of the brain is occupied by the association cortices raises a fundamental question: does more of it provide individuals with greater cognitive ability? Humans and other animals obviously vary in their talents and predispositions for a wide range of cognitive behaviors. Does a particular talent imply a greater amount of neural space in the service of that function?
Historically, the most popular approach to the issue of brain size and behavior in humans has been to relate the overall size of the brain to a broad index of performance, conventionally measured in humans by "intelligence" tests. This way of studying the relationship between brain and behavior has caused considerable trouble. In general terms, the idea that the size of brains from different species reflects intelligence represents a simple and apparently valid idea (see figure). The ratio of brain weight to body weight for fish is 1:5000; for reptiles it is about 1:1500; for birds, 1:220; for most mammals, 1:180, and for humans, 1:50. If intelligence is defined as the full spectrum of cognitive performance, surely no one would dispute that a human is more intelligent than a mouse, or that this difference is explained in part by the 3000-fold difference in the size of the brains of these species. Does it follow, however, that relatively small differences in the size of the brain among related species, strains, genders, or individualswhich often persist even after correcting for differences in body sizeare also a valid measure of cognitive abilities? Certainly no issue in neuroscience has provoked a more heated debate than the notion that alleged differences in brain size among racesor the demonstrable differences in brain size between men and womenreflect differences in performance. The passion attending this controversy has been generated not only by the scientific issues involved, but also by the spectre of racism or misogyny.
Nineteenth-century enthusiasm for brain size as a simple measure of human performance was championed by some remarkably astute scientists (including Darwin's cousin Francis Galton and the French neurologist Paul Broca), as well as others whose motives and methods are now suspect (see Gould, 1978, 1981 for a fascinating and authoritative commentary). Broca, one of the great neurologists of his day and a gifted observer, not only thought that brain size reflected intelligence, but was of the opinion (as was just about every other nineteenth-century male scientist) that white European males had larger and better-developed brains than anyone else. Based on what was known about the human brain in the late nineteenth century, it was perhaps reasonable for Broca to consider it an organ, like the liver or the lung, having a largely homogeneous function. Ironically, it was Broca himself who laid the groundwork for the modern view that the brain is a heterogeneous collection of highly interconnected but functionally discrete systems (see Chapter 27). Nonetheless, the simplistic nineteenth-century approach to brain size and intelligence has persisted in some quarters well beyond its time.
There are at least two reasons why measures such as brain weight or cranial capacity are not easily interpretable indices of intelligence, even though small observed differences may be statistically valid.
First is the obvious difficulty of defining and accurately measuring intelligence among animals, particularly among humans with different educational and cultural backgrounds.
Second is the functional diversity and connectional complexity of the brain. Imagine assessing the relationship between body size and athletic ability, which might be considered the somatic analogue of intelligence. Body weight, or any other global measure of somatic phenotype, would be a woefully inadequate index of athletic ability. Although the evidence would presumably indicate that bigger is better in the context of sumo wrestling or basketball, more subtle somatic features would no doubt be correlated with extraordinary ability in Ping Pong, gymnastics, or figure skating. The diversity of somatic function vis-à-vis athletic ability confounds the interpretation of any simple measure such as body size.
The implications of this analogy for the brain are straightforward.
Any program that seeks to relate brain weight, cranial capacity, or some other measure of overall brain size to individual performance ignores the reality of the brain's functional diversity. Thus, quite apart from the political or ethical probity of attempts to measure "intelligence" by brain size, by the yardstick of modern neuroscience (or simple common sense), this approach will inevitably generate more heat than light. A more rational approach to the issue, which has become feasible in the last few years, is
to relate the size of measurable regions of known function (the primary visual cortex, for example) to the corresponding functions (visual performance), as well as to cellular features such as synaptic density and dendritic arborization. These correlations have greater promise for functional validity, and less pretense of judgment and discrimination.
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DIT WAS HET LAATSTE DAT IK ER OVER POST; VOOR MIJ IS HET DUIDELIJK EN VOOR ZIJ DIE OPENMINDED ZIJN EN HET BELANGRIJKER VINDEN DE JUISTHEID TE VINDEN IPV GEWOON GELIJK TE WILLEN KRIJGEN IS HET OOK DUIDELIJK;