Реферат на тему Beauty Essay Research Paper Charles Darwin wrote
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Beauty Essay, Research Paper
Charles Darwin wrote in 1872 in his book “The Descent of Man”: “It is certainly not true that there is in the mind of man any universal standard of beauty with respect to the human body.
Although we “are all legally equal”, everyone knows that people are often treated differently according to their physical appearance. Even when we apply for jobs, appearance may dominate qualification. We even believe that attractive people are better – “what is beautiful is good” is a common standard in our thinking.
We have to admit that beauty standards might be different between cultures and between times, I will show in this essay that the underlying constraints, which shaped the standards, are the same. And that these constraints may be of an evolutionary origin.
Obsession and the shaping of our perception of attractiveness and beauty comes from human mate selection criteria, which have evolved through human evolutionary history, . In such a view, perception of attractiveness will be sex-specific because both sexes should have different aspirations for mates.
Nancy Etcoff, According to evolutionary considerations on a theoretical level females experience higher risk than males in opposite-sex interactions because they have the higher investment in the offspring. Since females invest more per offspring, their potential fertility is lower than that of males. Females are thus the limiting factor in reproduction and males have to compete for them. Females in turn choose among males. In humans, sex differences are most prominent in the role that status and physical attractiveness play in mate selection. Females value men’s socioeconomic status, with social position, prestige, wealth and so forth and use these as indicators, more than male attractiveness. In contrast, men attach greater value to women’s physical attractiveness, healthiness, and youth; all cues linked more with reproductive capacity than to female social status. Men are also more inclined to multiple short-term mating and less discriminating in their choice than females, whereas women are more interested in few long-term bonds and are more selective than males. It is noteworthy that these differences are relative and not absolute. Indeed, males are selective in choosing partners but females are even more selective. Males and females thus have different aspirations in mate-selection. Females, when interested in a long-term partner, look for males who are able to invest in their offspring and are willing to become involved in long-term relationships, i.e. males who are good competitors, reliable and friendly, those males who also have to be successful in male-male competition and strive for dominance. Males on the other hand can enhance their reproductive success either through philandering, or by reproducing with females who possess “good genes” and additional investing in the offspring. Possessing “good genes” thus would be equivalent to “being attractive” for males. Indeed males fixate female bodies more often whereas females fixate male bodies less often. The information females are looking for in males does not seem to lie in their bodily appearance – they concentrate on the male’s face.
Theories of Feature Processing: Pro. If attractiveness has any relation to mate-selection then we would expect two basic differences in the evaluation of traits in the opposite sex: first, those traits should be valued which guarantee optimal reproduction, that is youth and second, these traits should be basically those which are sexual dimorphic
In the human face the basic proportions are sexually dimorphic, male traits develop under the influence of testosterone and female traits develop under estrogen. In the case of the broad male chin as a feature of attractiveness the constraints seem to be known. If females want dominant males, broad chins may signal a tendency to dominate others. This is indeed the case. It has been shown that males with broad chins are perceived in 8 cultures as those who are likely to dominate others. Allan Mazurand colleagues have put comparable results forward. These authors describe careers of West Point cadettes – those with broad chins at entrance to West Point rose higher in the military hierarchy than others do. On the other hand a broad chin could signal an immunohandicap. This is the case because testosterone production might be costly, due to suppression of the immune function and thereby increasing disease susceptibility during puberty. Immunocompetence is highly relevant because the steroid reproductive hormones may negatively impact immune function.
When competition for mates is intense, some extreme traits might help to rivet a roving eye. A male peacock is saying ‘ look at me, I have this big tail. I couldn’t grow a tail this big if I had parasites’. Even if the trait is detrimental to survival, the benefit in additional offspring brought by attracting females can more than compensate for the decrease in longevity. The concept seems applicable to humans, because it helps resolve a nagging flaw in average-face studies.
Extreme male features advertise honestly that their bearer was sufficiently parasite resistant to produce them. But male facial features cannot become extreme, as expected. Perret and colleagues showed that adding a feminine touch to a male face makes it more attractive. The reason seems to be clear, broad jaws signal high testosterone levels and thus also possible aggressiveness. If females rely on stable relationships male aggressiveness may also turn against them. Thus there is an upper limit for male jaw width – this is when the feature might also become disadvantageous to females. In addition female chins and lower faces are small when they are attractive – this might signal the absence of male sex hormones and the presence of female sex hormones, which are a necessary prerequisite for reproduction.
Thus, markers of high estrogen may reliably signal an immune system of such high quality that it can deal with the handicap of high estrogen. Also, there is evidence that estrogen’s by-products are toxic in the body. Thus, markers of estrogen may honestly signal ability to cope with toxic metabolites. Sexual dimorphic traits in the human body can be found in the distribution of body fat (breast and buttocks), the general structure of the skeleton, that is bigger and more massive shoulders in males, and bigger pelvis in females, and finally muscle build. Male muscle build is probably the main differences. Again muscles are built up under the influence of male sex hormones, and muscles will be of use for males in male-male competition. The signaling value of body features in the case of females seems to be linked to reproductive stage. Sex differences in our bodies depend on fat distribution. The amount of fat in the female body is responsible for a stable household of female sex-steroids. Thus the amount of visible fat can predict if a female is receptive or not. The idea is that body fat must be distributed over prominent places like breasts and buttocks in order to strengthen signal value and not restrict the body’s ability to move and function. Indeed, for example breast size correlates with overall body fat. Furthermore, overall weight is linked to fertility: thick mothers have more children.
Women presented with a hyper-male face judged its owner as uncaring, aggressive and unlikely to be a good father. Female preference in male faces oscillate in tandem with the menstrual cycle, David Perett Nature June 1994, when a woman is ovulating she tend to prefer men with more masculine features; at less fertile times in her monthly cycle, she favors male faces with a softer, more feminine look.
Theories of Feature Processing: Contra. There are however many objections to a simple feature based approach to the decoding of attractiveness. One of them is based on our cognitive abilities: we are able to decode sex and attractiveness in a very short time. 100 msec of stimulus presentation is enough for reliable decoding. In this short time no feature analysis is possible, there must be some type of “Gestalt” or “Prototype” perception on a very low level of sensory integration and computation.
The Attractive Prototype: Faces. What could the “Gestalt” we use for attractiveness and beauty decoding then be? A basic feature of human cognition is the creation of “prototypes”. This means that we constantly evaluate stimuli from our social and non-social environment and classify these stimuli into categories and concepts, thus reducing the amount of environmental information into the “pieces” which can be used or stored very economically. For a first approach lets assume that prototypes are some kind of average representation of stimuli of one class. Indeed our brain seems to process faces this way. There are some hints that our brain solves the problem of storing faces with the help of prototypes. We seem to build facial prototypes and then simply store the deviations of a single face from these prototypes.
The Attractive Prototype: Faces. Several studies have repeatedly shown that computer generated prototypical faces are more attractive than the single faces which have been used for generating them. But there are two caveats: this is only replicable for female faces and all researchers find that there are some individual faces that are more attractive than the prototypes.
The Attractive Prototype: Bodies. Prototyping also does not apply only to faces. It is more complex. Devendra Singh describes a single measure, which can be linked constantly to bodily attractiveness. This is the waist hip-ratio in females. There is a curvilinear relationship to attractiveness with a maximum of attractiveness at 0.72. Surprisingly this maximum is related to many health features in females.
Moreover there is a direct link to fertility: females with an optimal WHR become more often and faster pregnant through artificial insemination.
But why would cognitive averaging have evolved? Evolutionary biology holds that in any given population, extreme characteristics tend to fall away in favor of average ones. Birds with unusually long or short wings die more often in storms. Human babies who are born larger or smaller than average are less likely to survive. The ability to from an average-mate template would convey a singular survival strategy. Inclination towards the average is called ” Koinophilia”
Theories of Prototype Processing: Pro. If our brain uses prototypes – averageness might well be coupled with being “prototypical”. Thus there might be a better fit of the stimulus onto the prototypical template. As a result, prototypes are recognized faster and better and thus might create higher nervous excitation. This fact could be the reason, that average is preferred. Our brain could accept more willingly better fitting stimuli. Andres Muller has called this process “neuroaesthetics”.
Donald Symons proposed that males should avoid mating with females who are at the extremes of a population, because these females may carry disadvantageous genes. Prototypes do portray some genetic information. With respect to features with additive genetic variance, homozygous individuals are over-represented at the extreme tails of the distributions. In contrast, heterozygous individuals are over-represented at the middle of such distributions. In contrast to this male gender prototypes are not average. We have seen that big single traits are attractive in males. This proposes an interesting speculation that for females there might be stabilizing selection, whereas for males directional selection is more important due to male – male competition. The most interesting thing with prototypes is that attractive prototyping allows two things: Firstly, we are able to adjust our beauty standards to the mean of the population. Media thus can create “unreal” beauty standards. Secondly, prototyping opens our possibilities of mate-choice. If we would have an innate template for attractiveness, we could run the danger of either never meeting somebody fitting the template, or being frustrated by the non-fitting mates we find.
Theories of Prototype Processing: Contra. One problem for prototyping is created by the fact, that we remember average faces very poorly, because they do not deviate from the templates we use to store faces. If this is true, we should expect deviations from average in beautiful faces. One has to be recognizable and distinct. So adding an individual touch to average ness could make an attractive face beautiful.
Second, we are quite aware to the fact that there are single faces, which are not prototypical at all – and they are constantly rated as more attractive. Third, symmetry could play a role – composite faces are much more symmetrical than the single faces, which are used to form the prototype.
Symmetry and Attractiveness. Bodily and facial asymmetries manifest themselves very early in human development and remain stable during lifetime. Asymmetry is the result of developmental instabilities during early embryonic development, and sometimes-extreme asymmetries occur after puberty. At this point we have to distinguish between MPA’s and bodily laterality. Usually both sides of the body differ – but the vertical body symmetry line can still be a straight line (although laterality is present). Asymmetry distort this straight line into a zigzag line.
Karl Grammer and Randy Thornhill has shown that facial symmetry is the main factor for ratings of female and male attractiveness (when controlled for averageness). In addition, bodily symmetry correlates with ratings of facial attractiveness (even when the body is not visible).
Comparable results can be found for the rating of bodily attractiveness in correlation with breast asymmetry. Symmetrical breasts are more attractive than asymmetrical breasts. Moreover, breast asymmetry is the best negative predictor for lactative ability and even for reproductive success. Thus bodily and facial symmetry may be good predictors for ratings of attractiveness.
Theories of Symmetry and Attractiveness: Pro. Parasite resistance should be a trait, which is valued in mate-selection. Thus symmetry may be an honest signal for mate quality. Symmetry as a mate-selection criterion has been shown in many species, from scorpion flies over birds to humans. Symmetrical persons of both sexes copulate earlier in life and have a higher frequency of copulations, and finally are able to select mates from a greater circle of associates.
Biologist Andres Muller and Randy Thornhill ” asymmetry can signal malnutrition, disease, or bad genes.” The tow have found that asymmetrical animals, ranging from barn swallows to lions, have fewer offspring and shorter lives.
Theories of Symmetry and Attractiveness: Contra. There are several objections against a theoretical connection between parasite resistance and bodily symmetry.
Body odor and pheromones : body odor and male perception of attractiveness. Several investigations on human body odor revealed the relevance of olfactory communication in humans and it’s implications for sexual behavior. Human body odor has been reported to influence female mate choice in order to find a partner that possesses fitting immune system components. Females find the body odor of those males attractive, whose immuno-histo-compatibility complex is highly variable to their own. In this case attractiveness of body odor leads to highly variable heterozygotic offspring. Moreover, as suggested by Karl Grammer, an important possible function of a pheromone would be the induction of affects, because emotions may change information processing in the receiver. Via a pathway to the limbic areas of the brain, the chemical signals carried by odors have a direct influence on emotions. Odors induce negative or positive moods and feelings. Indeed, odors modify the social perception of other persons.
Female pheromones. In their vaginal secretions female produce a sample of fatty acids, which are called copulins. Richard Michael and colleagues in Rhesus monkeys have discovered them. Rhesus males show no interest in ovariectomised rhesus females, presumably because ovariectomised rhesus females lose the odor characteristic of ovulation. Rhesus males regain interest in copulation when the vaginal secretions from non-ovariectomised females are applied to ovariectomise females. Studies on menstrual cycle fluctuations in the fatty-acid composition of women’s vaginal fluids indicated that a similar type of signaling system might also exist in humans. Human vaginal secretions have a composition that is similar to the vaginal secretions of female rhesus monkeys.
Copulins and male perception of females. Astrid Juette and colleagues tested the effect of copulins on male perception of female attractiveness. Interestingly copulins caused over all more positive ratings of females than control. But the effect is graduated: a woman that is rated without smell as very attractive gains less through smell than an unattractive-rated woman does. The less attractive a woman the more she gains through the additional information of her natural smell that a man receives.
Voice : Voice quality is another candidate. Unfortunately there is not much research in this direction. Zuckermann and Driver showed attractiveness prototypes in voices. People tend to agree what an attractive voice is. Dark low male voices are rated attractive. The biological background for such an attractiveness rating might lie in the fact, that usually the size of the voice producing apparatus correlate with body size, which is sexual dimorphic and thus again prototypical for males.
Age : Evolution would also instill an age preference. Human female fertility peaks in the early 20s, and so do assessments of female attractiveness. Between 1953 and 1990, the average age of playboy centerfold models was 21.3 years. Because men are fertile most of their adult lives, their attractiveness ratings remain relatively higher as their perceived age increases. Victor Johnson ” our feelings of beauty are exceptionally well turned to the age of maximum fertility.”
Considerable evidence has accumulated in recent years supporting the hypothesis that both facial and bodily physical attractiveness are health certifications and thus represent honest signals of phenotypic and genetic quality. Ellis and Donald Symons first proposed by Westermarck and the hypothesis that beauty connotes health later. There is no doubt, regarding all these variables, that beauty or attractiveness, are cognitive constructs in the eye of the beholder. Thus beauty, its signal values and cognitive processes are interlinked to a high degree.
The main aspect of my work presented here is the fact, that although different people might have different templates for beauty these templates underlie common construction principles. This also explains the high cultural and temporal variability of beauty standards. What we know is that mate selection criteria play a role in attractiveness ratings: females rate males as attractive who are dominant, males rate females as attractive who are healthy, receptive at the optimal age of reproduction and who promise high quality offspring. I will put forward that it is mainly “gender identification”: appearing as a “typical” male or a “typical” female in a certain environment will cause ratings as attractive. This means that sexually dimorphic traits are valued which signal youth. These traits then form the respective prototypes for the cognitive evaluation of attractiveness. In addition each theory of attractiveness has to take into account that a great deal of learning is involved. One of the conditions I posed at the beginning of this paper is the fact that “attractiveness” and “beauty” should be linked to reproductive success.
Human beauty has three components. In order of importance, there’s natural selection, which leads to the average face and the limited age rang. Then there’s sexual selection, which leads men, at least, to be attracted to exaggerated feminine traits like the small lower jaw and the fuller lips. Finally, there’s learning. It’s a fine-tuning mechanism that allows you to become even adapted to your environment and culture. It’s why one person can say “she is beautiful ” and the other can say ” she’s not quite right for me.”
Bibliography
- Lemley, Brad. Discover: The science of Beauty: are good looks nature’s ultimate survival strategy? , P.43 – 49, February 2000
- Grier, James W. and Theodore Burk. Biology of animal behavior: Reproductive behavior; Sexual reproduction and sexual selection. p. 318 – 358. 6th ed. 1984 Wm. C. Brown Communications, Inc. Iowa.
- Perrett, D. I., May, K. A. & Yoshikawa, S. (1994). Facial shape and judgment of female attractiveness.
Nature, 386, 239-242..
- Interview with Dr. Riyad Sadek. November 14th 2000.
- Etcoff, Nancy. Survival of the prettiest. 1999
- Darwin, Charles. The descent of man and selection in relation to sex. Penguin Books, 1954, London, England.
- Grammer, K., & Thornhill, R. (1994). Human (Homo sapiens) facial attractiveness and sexual selection:
The role of symmetry and averageness. Journal of Comparative Psychology, 108, 233-242.
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