Skin Color Differences Research Articles

Effects of Skin Color and Hair Differences on Facial Choices of Kindergarten Children

"Effects of Skin Color and Hair Differences on Facial Choices of Kindergarten Children." The Journal of Social Psychology, 107(2), pp. 287–288

Quantitative measurement of the vascular changes produced by UV radiation and carrageenin using the guinea-pig ear as the site of inflammation

The use of the guinea-pig ear as a site for the induction of experimental inflammation, using UV radiation or carrageenin, is described. The inflammatory response is localized, permitting separate quantitative measurement of erythema, vascular permeability, and edema. The intensity of erythema is determined by measuring skin temperature changes; this avoids difficulties with skin color differences encountered in other methods. The tissue does not require depilation. Vascular permeability changes and edema formation are determined, using, respectively, the determination of extravascular albumin content and changes in ear weight. The time course of the inflammatory response can be monitored by repeated determinations of ear temperature, permitting the identification of primary-phase and secondary-phase inflammation. The antiinflammatory effects of indomethacin, phenylbutazone, and aspirin are summarized; and paracetamol is shown to be inactive. It is suggested that the administration of potential antiinflammatory drugs may be so timed as to make available in the tissues maximal concentrations of drug during the secondary phase of the inflammatory response.

Racial differences in pigmentation and natural selection.

The inheritance of skin colour in man is not well understood. A clearer understanding could be obtained by taking into account the biological basis and genetical control of pigmentation in other mammals, particularly the experimental species. In these, most of the loci governing pigmentation are pleiotropic, colour being only one of the traits affected by them. Their products are evidently concerned with other metabolic pathways as well. There is strong evidence for inter-specific homology of pigmentation loci in mammals, and the situation in man may not be radically different. It is therefore possible that racial differences in skin colour may have resulted from the action of natural selection on these other functions of pigmentation genes.

Skin reflectance results from Holy Island, Northumberland.

The skin reflectance values at three EEL filters: 601, 605, and 609 of 100 inhabitants of Holy Island, Northumberland, are reported. They show no sex differences but a significant age difference and a marked regional difference. A method for examining regional differences in skin colour is introduced.

Chimaeric rabbits from embryonic cell transplantation.

SummaryEmbryonic single cells were successfully transplanted into preimplantation intact rabbit blastocysts. Phenotypic expression of the recipient blastocyst-donor cells genetic differences in the eye, skin, and coat color evidenced successful participation of transplanted cells in recipients organogenesis. An additional measure was the significant disproportionate sex ratio favoring the male in experimental neonates. It is, therefore, clearly established that the rabbit is a suitable model for micrurgical cell transplantation and further studies of cell interactions.

Education 2000 A.D.

In this article the author uses a mixture of historical evidence, extrapolation from present trends, and fantasies about the future to make some projections about the human condition in the year 2000. He then deduces what implications these projections bear for educational practice during the last quarter of the twentieth century. Some of the areas he touches upon in his analysis are the spread of affluence, developments in cybernation, the challenges of an information-rich society, changes in authority relationships, sex-role differences, skin-color differences, changes in space-consciousness, changes in time-orientation, population growth, the problems of violence, the use and abuse of drugs, ecological consciousness, the nurture of creativity and aesthetic sensitivity, and changes in religion.

A reflectometric study of the skin in Dutch families

In the period February–May 1968 the reflectances of the exposed (forehead) and unexposed (inside upper arm) skin, were measured at nine wavelengths (430, 470, 490, 520, 550, 580, 600, 660 and 685 mμ), using an “EEL” Reflectance Spectrophotometer in 100 Dutch families. The reflectance curves of upper arm and forehead show the shape usually found in white persons. The skin colour of the upper arm is lighter than that of the forehead in males and females. A difference in skin colour between males and females is observed. The forehead reflectances of males are lower than of females, and the upper arm reflectances of females are lower than those of males. A similarly directed sex difference in skin colour at the forehead has been found in other white groups. If no difference in reaction on exposure exists between both sexes, then the skin colour of the male upper arm will be lighter than that of females, although males in general are more exposed to radiation, because male arms are less uncovered than female arms. No change in skin colour at the upper arm is observed during ageing. As judged from the wavelengths concerned the changes in skin colour at the forehead during ageing result for the greater part both from a regular accumulation of melanin, and an increase in the blood flow of the skin, particularly during the years 11–25. Intrafamilial reflectance resemblances are investigated by means of correlations computed from the upper arm reflectance values measured at wavelengths 550 and 685 mμ. Significant positive correlations between the parents, 0·299 (wavelength 550 mμ) and 0·226 (wavelength 685 mμ) respectively, indicate positive assortative mating. The pattern of intrafamilial correlation coefficients suggests a role of X-chromosomal genes in the causation of the variability in the reflectances measured at wavelength 685 mμ (a measure of melanin deposition). Intrafamilial correlation computations of reflectances measured at wavelength 550 mμ (a measure of vascular response) show some positive correlations, but the role of genes in the causation of the variability in these reflectances remains unclear.

Genetic drift and polygenic inheritance.

AbstractThe interaction of random gene drift and selection was studied by computer simulation for two quantitative traits, which were considered to approximate stature and skin color differences in human populations. The expected effects of gene drift, fixation of alleles and reduction of genotypic and phenotypic variances, were found in the simulation. Stabilizing selection, which seems to be the type of selection operating on these traits, was found to increase the effects of gene drift. Since there seems to be no evidence of reduction in phenotypic and presumably genotypic variability in small human populations, the applicability of these simple genetic models to human traits raises problems for which several possible solutions exist.

Sex differences in skin colour in man.

SummarySkin reflectances were obtained at 685 mμ wave length from the medial upper arm and the forehead regions among 105 Tibetan males and 105 Tibetan females, in order to study sex differences in human skin pigmentation. The forehead pigmentation of males was always found to be darker than that of females, and the difference to be significant during middle and late adolescence The medial upper arm pigmentation of girls was found to be darker than that of boys, during early adolescence; but during middle adolescence the two sexes exhibited just similar pigmentation and during late adolescence females emerged to be significantly lighter than males. The present study, thus, suggests that one of the factors causing sex differences in human skin pigmentation may be the physiological changes occurring during adolescence, which may be genetically determined.

Camouflage for disfiguring skin lesions

Certain abnormalities of exposed skin may turn sensitive individuals into social and psychological cripples. These conditions are mostly untreatable by orthodox medical or surgical methods, but they can often be disguised. Differences in skin colour can be more effectively disguised than differences in texture.

Racial Differences in Skin Color: Sir:

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Reactions in a projective doll-play interview of white males 2 to 6 years of age to differences in skin color and facial features.

(1950). Reactions in a Projective Doll-Play Interview of White Males Two to Six Years of Age to Differences in Skin Color and Facial Features. The Pedagogical Seminary and Journal of Genetic Psychology: Vol. 76, No. 2, pp. 323-341.

Racial Differences in Skin-Colour as Recorded by the Colour Top.

Racial Differences in Skin-Colour as Recorded by the Colour Top.