揭秘：你為什么長得這么好看
BEAUTY, the saying has it, is only skin deep. Not true. Skin is important (the cosmetics industry proves that). But so is what lies under it. In particular, the shape of people’s faces, determined by their bone structure, contributes enormously to how beautiful they are. And, since the ultimate point of beauty is to signal who is a good prospect as a mate, what makes a face beautiful is not only an aesthetic matter but also a biological one. How those bone structures arise, and how they communicate desirable traits, are big evolutionary questions.
Until now, experiments to try to determine the biological basis of beauty have been of the please-look-at-these-photographs-and-answer-some-questions variety. Some useful and not necessarily obvious results have emerged, such as that one determinant of beauty is facial symmetry.
But what would really help is a breeding experiment which allowed the shapes of faces to be followed across the generations to see how those shapes relate to variations in things that might be desirable in a mate. These might include fertility, fecundity, social status, present health, and likely resistance to future infection and infestation. Correlations between many of these phenomena and attributes of the body-beautiful have, indeed, been established. But in a pair-forming, highly social species such as Homo sapiens, you also have to live with your co-child-raiser or, at least, collaborate with him or her. So other things may be important in a mate, too, such as an even temper and a friendly outlook.
It would be impossible to do such a breeding experiment on people, of course. But as Irene Elia, a biological anthropologist at Cambridge, realised, it has in fact been done, for the past five decades, on a different species of animal. Dr Elia has published her analysis of this experiment in the Quarterly Review of Biology. The animals in question are foxes.
迄今，探究美貌生物學(xué)基礎(chǔ)的科學(xué)實(shí)驗(yàn)，仍然離不開人的感官和實(shí)驗(yàn)中的相關(guān)問題。一些研究結(jié)果有價值而不明顯，比如臉形對稱。
其中人類的繁殖實(shí)驗(yàn)意義重大。人類繁殖使臉形一代一代傳承，從中可以分辨出后代臉形變體傳承父母美貌的成因，其中包括能育力、生產(chǎn)力、社會地位、現(xiàn)實(shí)的身體狀況和未來的身體免疫能力。許多現(xiàn)象都被看做美貌的因素，事實(shí)也是如此。不同的是，人類是兩性高級社會動物，配偶雙方共同撫育后代，或者至少有一方撫養(yǎng)。因此可能還有其他重要的影響因素，比如配偶平和的性格與和善的外貌。
雖然人類繁殖實(shí)驗(yàn)難以實(shí)現(xiàn)，但劍橋大學(xué)人類生物學(xué)家艾琳·伊利亞耗費(fèi)50年，最終完成了不同物種的繁殖實(shí)驗(yàn)。伊利亞博士已將實(shí)驗(yàn)分析結(jié)果發(fā)表在《生物學(xué)評論季刊》。實(shí)驗(yàn)研究的動物是狐貍。
Foxy ladies, vulpine gents
The story starts in 1959, in Novosibirsk, Russia. That was when Dmitry Belyaev, a geneticist, began an experiment which continues to this day. He tried to breed silver foxes (a melanic colour variant, beloved of furriers, of the familiar red fox) to make them tamer and thus easier for farmers to handle. He found he could, but the process also had other effects: the animals’ coats developed patches of colour; their ears became floppy; their skulls became rounded and foreshortened; their faces flattened; their noses got stubbier; and their jaws shortened, thus crowding their teeth.
All told, then, these animals became, to wild foxes, the equivalent of what dogs are to wild wolves. And this was solely the result of selection for what Belyaev called “friendly” behaviour—neither fearful nor aggressive, but calm and eager to interact with people.
The link appears to be hormonal. Hormones such as estradiol and neurotransmitters such as serotonin, which regulate behaviour, also regulate some aspects of development. Change one and you will change the other. So in a species where friendliness is favoured because that species is social and the group members have to get on with each other—a species like Homo sapiens, for example—a “friendly” face is a feature that might actively be sought, both in mates and in children, because it is a marker of desirable social attitudes. And there is abundant evidence, reviewed by Dr Elia, both that it is indeed actively sought by Homo sapiens, and that it is such a reliable marker.
What men look for in the faces of women, and vice versa, is so well known that research might seem superfluous. Suffice to say, then, that features like those seen in Belyaev’s foxes (flat faces, small noses, reduced jaws and a large ratio between the height of the cranium and the height of the face) are on the list. People with large craniofacial ratios are, literally, highbrow.
More intriguingly, the presence or absence of such features skews parents’ attitudes to their offspring. At least 15 studies have shown that mothers treat attractive children more favourably than unattractive ones, even though they say they don’t and may actually believe that. At least one of these studies showed this bias is true from birth.
Some of the details are extraordinary. One researcher, who spent a decade observing how mothers look after young children in supermarkets, found that only 1% of children judged unattractive by independent assessors were safely secured in the seats of grocery carts. In the case of the most attractive the figure was 13%. Another researcher studied police photographs of children who had been abused and found such children had lower craniofacial ratios than those who had not been.
In a state of nature, this sort of behaviour would surely translate into selective death and thus the spread of the facial features humans are pleased to describe as “beautiful”. If such features do indicate a propensity to friendly, sociable behaviour, as they do in foxes, then such behaviours will spread too.
Crucially for Dr Elia’s hypothesis, they do indeed indicate such a propensity. Even as children, according to 33 separate studies, the attractive are better adjusted and more popular than the ugly (they also have higher intelligence, which assists social skills). And of course, they have less difficulty finding a mate—and as a result have more children themselves. One study found that the most beautiful women in it had up to 16% more offspring than their less-favoured sisters. Conversely, the least attractive men had 13% fewer than their more handsome confrères.
狡黠的狐貍
故事源于1959年的俄羅斯新西伯利亞。遺傳學(xué)家德米特里·貝爾耶夫做了一項(xiàng)實(shí)驗(yàn)，他試圖馴化一批銀狐供農(nóng)民使用，從中發(fā)現(xiàn)，狐貍表皮變?yōu)榘郀?，耳朵下垂，頭骨變小，面部變平，鼻梁下塌，下巴變短，牙縫變窄。
馴化的狐貍就像野狼被馴化成狗。貝爾耶夫把該選擇結(jié)果稱為“友好行為”，這種選擇既不令人害怕也沒有攻擊傾向，反之，樂于與人相處。
這種現(xiàn)象與激素有關(guān)，比如雌激素和神經(jīng)傳遞素，它們會調(diào)節(jié)動物的生理行為，對動物進(jìn)化有重要影響。所以那些社會群居物種行為比較友好，因?yàn)樗鼈冃枰幚硐嗷リP(guān)系。以現(xiàn)代人為例，結(jié)婚和生子時，看起來更“友好”，因?yàn)檫@代表著積極的社會態(tài)度，伊利亞博士對此提供了大量證據(jù)。
男人喜歡什么長相的女人，這一點(diǎn)大家都知道，研究這個似乎是多余的?？梢赃@么說，受歡迎的一些面貌特征就像貝爾耶夫馴化的狐貍一樣(扁平的臉、小鼻子、下巴短、頭蓋骨高度和臉長之間比例大)。那些顱面部比例大的人通常被認(rèn)為是文化修養(yǎng)高的人。
更可笑的是，他們把外部特征與父母對孩子的態(tài)度聯(lián)系起來。至少有15項(xiàng)研究顯示漂亮的孩子更招媽媽待見。其中至少有一項(xiàng)表明這種偏見從孩子出生時就存在。
一些相關(guān)細(xì)節(jié)出人意料。一名研究員花了十年觀察媽媽購物時如何照看孩子，發(fā)現(xiàn)在被評為不漂亮的孩子中，只有1%得到細(xì)心照料，而漂亮的孩子中這一比例為13%。另一研究員發(fā)現(xiàn)長期遭受虐待的孩子顱面比值比較小。
自然狀態(tài)下，這種行為漸漸消失，廣泛被接受的臉形，我們稱之為“美”。如果這種特征被認(rèn)定為友好的社會行為，這種行為也會不斷擴(kuò)大。
伊利亞博士的傾向性假設(shè)已被證實(shí)存在。33項(xiàng)研究表明漂亮的孩子更能適應(yīng)社會，更受歡迎，智商更高，社交能力也更強(qiáng)。當(dāng)然，這些人也更容易找到對象，育嬰率也高。其中一項(xiàng)研究發(fā)現(xiàn)相對漂亮的女士育嬰率要高出16%;相對英俊的男士繁殖率也會高出13%。
The beholder’s eye
An appreciation of what is “beautiful”, moreover, seems innate—as Dr Elia’s hypothesis requires it should be. Babies a few days old prefer pictures of the faces of people whom their elders would define as beautiful to those they would not, regardless of the sex and race of either the baby or the person in the photo.
People also seem to be more beautiful now than they were in the past—precisely as would be expected if beauty is still evolving. This has been shown by assessing the beauty of reconstructions of the faces of early humans. (Such reconstructions, sometimes used in murder cases where only skeletal remains of the victim are available, produce reliable depictions of recently dead people, so the assumption is that ancients really did look like the reconstructions made of them.)
None of this absolutely proves Dr Elia’s hypothesis. But it looks plausible. If she is right, facial beauty ceases to be an arbitrary characteristic and instead becomes a reliable marker of underlying desirable behaviour. It is selected for both in the ways beautiful children are brought up, and in the number of children the beautiful have. Face it.(ChinaDaily)
他人眼中的美
審美力是天生的——伊利亞博士的假設(shè)就是以此為標(biāo)準(zhǔn)。嬰兒剛出生時的喜好決定了將來的審美觀念，這沒有性別、種族和認(rèn)識對象的差別。
人類越長越漂亮——美在朝著人所期待的方向進(jìn)化。復(fù)原的早期人類面部已證實(shí)這一點(diǎn)。兇殺案中，有時會根據(jù)對死者的描述，復(fù)原死者面貌，這可以證明早期人類面貌復(fù)原的真實(shí)性。
這些研究都不能完全證明伊利亞博士的假說。但這個假說貌似挺有道理的。如果她的假設(shè)正確，那么美貌就不再是偶然獲得的特質(zhì)，而是積極的社會行為選擇的結(jié)果，美貌成了這種行為的可靠標(biāo)記。這種選擇包含兩個方面，一是漂亮的小孩成長更順利，一是漂亮的人會生育更多小孩。直面這個現(xiàn)實(shí)吧。
