Why music?

Human evolution 人类进化 Why music? 音乐缘何而起？ Dec 18th 2008 From The Economist print edition Biologists are addressing one of humanity's strangest attributes, its all-singing, all-dancing culture 生物学家正在对人类最怪异的特征――载歌载舞的文化――加以解释 "IF MUSIC be the food of love, play on, give me excess of it." And if not? Well, what exactly is it for? The production and consumption of music is a big part of the economy. The first use to which commercial recording, in the form of Edison's phonographs, was to bring music to the living rooms and picnic tables of those who could not afford to pay live musicians. Today, people are so surrounded by other people's music that they take it for granted, but as little as 100 years ago singsongs at home, the choir in the church and fiddlers in the pub were all that most people heard. "如果音乐是爱的食粮，奏下去，直到漫溢。"如果不是呢？究竟音乐是为了什么？音乐的生产和消费是经济的重要组成部分。以爱迪生的留声机形式首度出现的商业录音，就是为了将音乐带入那些请不起现场乐队的家庭，引入他们的客厅和野餐桌上。今天，人们已经被音乐层层包围，觉得不足为奇，但就在100年前，大部分人们听到的不过是家中的吟唱，教堂的唱诗和酒吧中的小提琴手。 Other appetites, too, have been sated even to excess by modern business. Food far beyond the simple needs of stomachs, and sex (or at least images of it) far beyond the needs of reproduction, bombard the modern man and woman, and are eagerly consumed. But these excesses are built on obvious appetites. What appetite drives the proliferation of music to the point where the average American teenager spends 1½-2½ hours a day―an eighth of his waking life―listening to it? 其他欲望也和音乐一样，在现代商业的作用下甚至发展到闲赘。食物远非仅仅填饱肚子，性（至少是与性有关的画面）远非仅为繁衍，它们都像炮弹一样轰炸着现代人的头脑，还十分畅销。不过这些过度消费建立于显而易见的欲望之上。是什么样的需求推动着音乐的繁荣，让美国青少年每天平均花1½-2½小时――即清醒时间的八分之一――洗耳恭听呢？ Well, that fact―that he, or she, is a teenager―supports one hypothesis about the function of music. Around 40% of the lyrics of popular songs speak of romance, sexual relationships and sexual behaviour. The Shakespearean theory, that music is at least one of the foods of love, has a strong claim to be true. The more mellifluous the singer, the more dexterous the harpist, the more mates he attracts. 受众是青少年这一事实，对音乐功能假说之一提供了支撑。约40%流行歌曲的作词都在讲述爱情，两性关系和性行为。莎翁曰，音乐至少为爱情食粮之一，很大程度上是正确的。歌手声音愈甜美，竖琴师弹奏越流畅，吸引的异性就越多。 A second idea that is widely touted is that music binds groups of people together. The resulting solidarity, its supporters suggest, might have helped bands of early humans to thrive at the expense of those that were less musical. 第二种广泛受到支持的说法是，音乐将人们联系到了一起。该理论的支持者认为，由此产生的团结可能帮助早期人群变得更加繁荣，音乐细胞不发达的群体则遭到淘汰。 Both of these ideas argue that musical ability evolved specifically―that it is, if you like, a virtual organ as precisely crafted to its purpose as the heart or the spleen. The third hypothesis, however, is that music is a cross between an accident and an invention. It is an accident because it is the consequence of abilities that evolved for other purposes. And it is an invention because, having thus come into existence, people have bent it to their will and made something they like from it. 这两种观点都认为，音乐能力是特别发展起来的――也可以说是一个假想中完全为某种功能而产生的器官，类似心脏或脾脏。第三种假设却认为，音乐是偶然和创造的交集。说它是偶然，因为音乐是本为他用的能力产生的结果。说是创造，因为音乐自产生以来，人们就将它按照自己的意愿塑造，并从中得到所爱。 She loves you 她爱你 Shakespeare's famous quote was, of course, based on commonplace observation. Singing, done well, is certainly sexy. But is its sexiness the reason it exists? Charles Darwin thought so. Twelve years after he published "On the Origin of Species", which described the idea of natural selection, a second book hit the presses. "The Descent of Man and Selection in Relation to Sex" suggested that the need to find a mate being the pressing requirement that it is, a lot of the features of any given animal have come about not to aid its survival, but to aid its courtship. The most famous example is the tail of the peacock. But Darwin suggested human features, too, might be sexually selected in this way―and one of those he lit on was music. 莎翁名言当然基于日常观察。歌唱得好，固然性感。但性感是音乐存在的原因吗？查尔斯•达尔文认为如此。出版描述自然选择思想的《物种起源》十二载后，他的第二部书也付梓印刷。《人类的由来及性选择》称，寻求配偶的需求十分迫切，因此任意物种许多特征的存在并非为生存，而是为求偶。最著名的案例就是孔雀尾。但达尔文同时表示，人类特征可能也是由此方式进行的性选择――他阐述的其中一点就是音乐。 In this case, unlike that of natural selection, Darwin's thinking did not set the world alight. But his ideas were revived recently by Geoffrey Miller, an evolutionary biologist who works at the University of New Mexico. Dr Miller starts with the observations that music is a human universal, that it is costly in terms of time and energy to produce, and that it is, at least in some sense, under genetic control. About 4% of the population has "amusia" of one sort or another, and at least some types of amusia are known to be heritable. Universality, costliness and genetic control all suggest that music has a clear function in survival or reproduction, and Dr Miller plumps for reproduction. 这一次，达尔文的观点并没有像自然选择学说一样，轰动世界。但他的观点最近被新墨西哥大学进化生物学家杰弗里•米勒恢复了生机。首先，米勒博士观察到：音乐在人类中普遍存在，生产过程消耗时间和精力，并且最起码在某些意义上受基因控制。约4%人口患有各种程度的"失歌症"，并且我们已经知道至少某些失歌症具有遗传性。普遍性、消耗性和基因控制，这些都显示音乐在生存和繁衍方面具有明显作用，米勒博士认为这是出于繁衍之故。 One reason for believing this is that musical productivity―at least among the recording artists who have exploited the phonograph and its successors over the past hundred years or so―seems to match the course of an individual's reproductive life. In particular, Dr Miller studied jazz musicians. He found that their output rises rapidly after puberty, reaches its peak during young-adulthood, and then declines with age and the demands of parenthood. 该观点理由之一：音乐产量――至少在近百年来在利用留声机或留声机的升级产品留下录音的艺术家之中――似乎符合个人的生育期过程。米勒博士研究了爵士音乐家，发现他们的产量在青春期后迅速上升，青年时代达到顶峰，而后随年龄增长和照顾孩子的需要逐年下降。 As is often the case with this sort of observation, it sounds unremarkable; obvious, even. But uniquely human activities associated with survival―cooking, say―do not show this pattern. People continue to cook at about the same rate from the moment that they have mastered the art until the moment they die or are too decrepit to continue. Moreover, the anecdotal evidence linking music to sexual success is strong. Dr Miller often cites the example of Jimi Hendrix, who had sex with hundreds of groupies during his brief life and, though he was legally unmarried, maintained two long-term liaisons. The words of Robert Plant, the lead singer of Led Zeppelin, are also pertinent: "I was always on my way to love. Always. Whatever road I took, the car was heading for one of the greatest sexual encounters I've ever had." 在此种类型的观察中，这样的结论并不足为怪；甚至可以说显然。但人类特有的与生存相关的活动――如做饭――并未显示出这样的规律。人类从掌握做饭技巧的那一刻起，到死去或身体过于虚弱无法继续，做饭的频率都大致相同。而且，关于音乐和性成功的传闻也有很强的证据意义。米勒博士经常援引吉米•亨德里克斯的例子，他不长的一生中，和几百位歌迷发生过性关系，虽然从法律意义上讲他没有结婚，却保持了两段长期的感情。英国摇滚乐队雷德•泽培林主唱罗伯特•普兰特的唱词也非常贴切："我总是在爱情的路上。总是在爱情的路上。不管我选择何种道路，车子总将开往我所经历的最美好的性爱。" Another reason to believe the food-of-love hypothesis is that music fulfils the main criterion of a sexually selected feature: it is an honest signal of underlying fitness. Just as unfit peacocks cannot grow splendid tails, so unfit people cannot sing well, dance well (for singing and dancing go together, as it were, like a horse and carriage) or play music well. All of these activities require physical fitness and dexterity. Composing music requires creativity and mental agility. Put all of these things together and you have a desirable mate. "爱情食粮"假说的另一个根据，是音乐满足性选择特点的主要标准：它是基本生存适合度的可靠信号。就好比不适合生存的孔雀不能长出美丽的雀尾，不适合生存的人类也不能唱出美妙的歌曲，跳起迷人的舞蹈（唱歌跳舞就好比马和马车一样紧密结合），抑或流畅演奏。这些活动都需要生理上的适宜和灵巧。作曲需要创造力和思维的敏捷。将这些联系起来，就是您理想中的配偶。 Improve your singing… 提高演唱能力 A third reason to believe it is that music, or something very like it, has evolved in other species, and seems to be sexually selected in those species, too. Just as the parallel evolution of mouse-like forms in marsupial and placental mammals speaks of similar ways of life, so the parallel evolution of song in birds, whales and gibbons, as well as humans, speaks of a similar underlying function. And females of these animals can be fussy listeners. It is known from several species of birds, for example, that females prefer more complex songs from their suitors, putting males under pressure to evolve the neurological apparatus to create and sing them. 第三点理由，音乐――或同音乐十分相似的事物――在其他物种中也有进化，并且在这些物种中似乎也是通过性选择。有袋和胎盘哺乳动物中与鼠类平行进化，表明它们的生活方式相似，因此鸟类、鲸类、猿类，以及人类间歌曲的平行进化，也说明了歌曲基本功能相同。上述动物的雌性都是非常挑剔的听众。从一些鸟类中我们得知，雌性喜欢听它们的追求者唱更为复杂的歌曲，雄性在这样的压力下就发展神经系统，进行创作和演唱。 And yet, and yet. Though Dr Miller's arguments are convincing, they do not feel like the whole story. A man does not have to be gay to enjoy the music of an all-male orchestra, even if he particularly appreciates the soprano who comes on to sing the solos. A woman, meanwhile, can enjoy the soprano even while appreciating the orchestra on more than one level. Something else besides sex seems to be going on. 不过呢，不过呢。纵使米勒博士的论据非常有说服性，却不能解释全部问题。不是男同性恋，也可以欣赏全男管弦乐队的音乐，即便他尤其欣赏的是上台独唱的女高音。女性也可以喜欢女高音，同时在不同程度上欣赏管弦乐队。除了性，似乎还有其他因素。 The second hypothesis for music's emergence is that it had a role not just in helping humans assess their mates, but also in binding bands of people together in the evolutionary past. Certainly, it sometimes plays that role today. It may be unfashionable in Britain to stand for the national anthem, but two minutes watching the Last Night of the Proms, an annual music festival, on television will serve to dispel any doubts about the ability of certain sorts of music to instil collective purpose in a group of individuals. In this case the cost in time and energy is assumed to be repaid in some way by the advantages of being part of a successful group. 音乐起源的第二种假说认为，音乐不仅帮助人类评价配偶，而且在人类进化过程中将大家联系在一起。当然，音乐今天也会体现这样的作用。在英国，听到国歌起立可能不那么入流，但看两分钟英国年度盛典"最后的舞会"电视节目，就不会怀疑，一些种类音乐能在一群个体中灌输集体精神。在这种情况下，我们认为，作为某成功团体一部分而产生的优越感，对时间和精力上的消耗以某种方式做出偿还。 The problem with this hypothesis is that it relies on people not cheating and taking the benefits without paying the costs. One way out of that dilemma is to invoke a phenomenon known to biologists as group selection. Biologically, this is a radical idea. It requires the benefits of solidarity to be so great that groups lacking them are often extinguished en bloc. Though theoretically possible, this is likely to be rare in practice. However, some researchers have suggested that the invention of weapons such as spears and bows and arrows made intertribal warfare among early humans so lethal that group selection did take over. It has been invoked, for example, to explain the contradictory manifestations of morality displayed in battle: tenderness towards one's own side; ruthlessness towards the enemy. In this context the martial appeal of some sorts of music might make sense. 这种假说的问题在于，它需要人们在不支付成本的条件下不作弊，不享受好处。解决方法之一就是构造生物学家所谓的群体选择现象。生物学上来说，这样的观念可谓激进。团结的优势需要非常强大，而没有团结精神的群体通常会整体消失。尽管理论上存在这样的可能性，实际却十分罕见。然而，已有科学家认为，诸如长矛、弓箭等武器的发明，使人类早期部落间战争具有很强的致命性，而确实产生过群体选择。这种观点已用来解释战争中道德上的矛盾：对自己人温和，对敌人无情。这样分析，某些音乐的武力感召可能不无道理。 Robin Dunbar of Oxford University does not go quite that far, but unlike Dr Miller he thinks that the origins of music need to be sought in social benefits of group living rather than the sexual benefits of seduction. He does not deny that music has gone on to be sexually selected (indeed, one of his students, Konstantinos Kaskatis, has shown that Dr Miller's observation about jazz musicians also applies to 19thcentury classical composers and contemporary pop singers). But he does not think it started that way. 牛津大学教授罗宾•邓巴还未深入到这般，但与米勒博士不同，他认为音乐的起源需要从群体生活的社会利益中探寻，而非吸引异性方面的两性利益。他并没否认音乐在性选择中发展（实际上他的一名学生康斯坦丁诺•卡斯卡迪斯已证明，米勒博士对于爵士音乐家的观察结果同样适用于19世纪的古典乐作曲家和当代的流行乐手）。但他并不认为音乐始于斯。 …and your grooming 注意仪容仪表 Much of Dr Dunbar's career has been devoted to trying to explain the development of sociality in primates. He believes that one of the things that binds groups of monkeys and apes together is grooming. On the face of it, grooming another animal is functional. It keeps the pelt clean and removes parasites. But it is an investment in someone else's well-being, not your own. Moreover, animals often seem to groom each other for far longer than is strictly necessary to keep their fur pristine. That time could, in principle, be used for something else. Social grooming, rather like sexual selection, is therefore a costly (and thus honest) signal. In this case though, that signal is of commitment to the group rather than reproductive prowess. 邓巴教授的职业生涯中，大部分时间都在努力对灵长类动物的交际发展做出解释。他认为，将猴群和猿群结合在一起的方式之一就是它们整理毛发的行为。表面看来，为其他动物整理毛发是有实际功用的：可以保持皮毛洁净，去除寄生虫。但这是对其他个体健康的投入，而非自身。何况动物为对方整理毛发的时间，比严格意义上保持皮毛洁净所需要长许多。这时间原则上说，可以用来做其他的事情。群体中毛发整理行为和性选择十分相似，是一种需要投入（因此可靠）的信号。然而在这一案例中，信号是对群体的忠诚，而无关生殖能力。 Dr Dunbar thinks language evolved to fill the role of grooming as human tribes grew too large for everyone to be able to groom everyone else. This is a controversial hypothesis, but it is certainly plausible. The evidence suggests, however, that the need for such "remote grooming" would arise when a group exceeds about 80 individuals, whereas human language really got going when group sizes had risen to around 140. His latest idea is that the gap was bridged by music, which may thus be seen as a precursor to language. 邓巴博士认为，随着人类群体愈发壮大，个体不能为其他所有个体梳理毛发，语言就发展起来填补空缺。这种假设很具争议，但的确有可能。证据显示，如若群体中个体数目超过80，就会产生"远程梳理"的需要，而人类语言是在个体数量发展到140时诞生。他最近提出，其间的沟壑由音乐填补――而音乐也可以看视为语言的先驱。 The costliness of music―and of the dancing associated with it―is not in doubt, so the idea has some merit. Moreover, the idea that language evolved from wordless singing is an old one. And, crucially, both singing and dancing tend to be group activities. That does not preclude their being sexual. Indeed, showing off to the opposite sex in groups is a strategy used by many animals (it is known as lekking). But it may also have the function of using up real physiological resources in a demonstration of group solidarity. 音乐――及其相联系的舞蹈――的消耗性质毋庸置疑，因此这样的观点不无道理。此外，语言发迹于无词歌唱，这样的理论早有提出。重要的一点是，歌唱和舞蹈是都群体活动。这并不能否认它们与性相关。实际上，向群体中异性炫耀是许多动物使用的策略（也就是所谓的求偶集会），但可能也用作通过消耗真正的生理资源，以显示群体团结。 By side-stepping the genocidal explanations that underlie the classical theory of group selection, Dr Dunbar thinks he has come up with an explanation that accounts for music's socially binding qualities without stretching the limits of evolutionary theory. Whether it will pass the mathematical scrutiny which showed that classical group selection needs genocide remains to be seen. But if music is functional, it may be that sexual selection and social selection have actually given each other a helping hand. 避开群体选择基础的经典理论――群族灭绝，邓巴教授认为自己发现了可以在进化理论内，对音乐的社会联系特点进行解释。这种说法是不是经得住数学的考验（数学研究显示经典群体选择需要群族灭绝），仍有待观察。但若音乐果真是一种工具，可能是性选择和社会选择相互作用的结果。 The third hypothesis, though, is that music is not functional, and also that Dr Dunbar has got things backwards. Music did not lead to language, language led to music in what has turned out to be a glorious accident―what Stephen Jay Gould called a spandrel, by analogy with the functionless spaces between the arches of cathedrals that artists then fill with paintings. This is what Steven Pinker, a language theorist at Harvard, thinks. He once described music as auditory cheesecake and suggested that if it vanished from the species little else would change. 第三种假设却认为，音乐并非功用性，邓巴教授对此也作出解释。音乐并非语言先驱，语言发展出音乐不过是个美丽的意外――斯蒂芬•杰伊•古尔德所谓的"拱肩"，他将其比作教堂拱门的留白，被艺术家挂上画作。哈佛大学语言理论学家史蒂芬•平克亦认为如此。他曾经将音乐比作一个听觉芝士蛋糕，称如果蛋糕从同种之间消失，没什么会发生改变。 Dr Pinker's point is that, like real cheesecake, music sates an appetite that nature cannot. Human appetites for food evolved at a time when the sugar and fat which are the main ingredients of cheesecake were scarce. In the past, no one would ever have found enough of either of these energy-rich foods to become obese, so a strong desire to eat them evolved, together with little limit beyond a full stomach to stop people eating too much. So it is with music. A brain devoted to turning sound into meaning is tickled by an oversupply of tone, melody and rhythm. Singing is auditory masturbation to satisfy this craving. Playing musical instruments is auditory pornography. Both sate an appetite that is there beyond its strict biological need. 平克博士认为，音乐就好像真正的芝士蛋糕一样，满足了一种自然界无法满足的欲望。人们对食物的欲望在糖和脂肪匮乏的时代得以发展，而糖和脂肪正是芝士蛋糕的主要原料。过去，这两种高能量的食物稀少，没有人能因它们肥胖，所以食用的强烈欲望得以发展，而若非吃饱，也没有什么力量能阻止人们食用过量。音乐也是如此。如大脑全力将声音转化为意义，那么过量供给音调、旋律和节奏会让其感到愉悦。歌唱就是听觉自慰，用作满足这种渴望。演奏乐器就是听觉毛片。两者都满足严格意义上生理需求之外的欲望。 Of course, it is a little more complicated than that. People do not have to be taught to like cheesecake or sexy pictures (which, in a telling use of the language, are sometimes also referred to as "cheesecake"). They do, however, have to be taught music in a way that they do not have to be taught language. 当然不是这么简单。人们不需教育就喜欢芝士蛋糕或香艳图片（在英语中香艳图片有时也会被称为"芝士蛋糕"）。音乐则与语言不同：语言无需刻意教授，而音乐需要专门学习。 Words and music 文字与音乐 Aniruddh Patel, of the Neurosciences Institute in San Diego, compares music to writing, another widespread cultural phenomenon connected with language. True language―the spoken languages used by most people and the gestural languages used by the deaf―does not have to be taught in special classes. The whole of a baby's world is its classroom. It is true that parents make a special effort to talk to their children, but this is as instinctive as a young child's ability (lost in his early teens) to absorb the stuff and work out its rules without ever being told them explicitly. 圣地亚哥神经科学院教授阿尼鲁德•帕特尔将音乐与写作――另外一种和语言相关的文化现象――进行比对。真正的语言――大部分人使用的口语和聋哑人使用的手语――无需在特别的课堂中教授。婴儿的全部世界就是他的教室。没错，父母会努力教孩子说话，但是婴儿出于本能，就能在没有明确教导的情况下，吸收知识，总结规则（该能力在青少年时期消失）。 Learning to write, by contrast, is a long-winded struggle that many fail to master even if given the opportunity. Dyslexia, in other words, is common. Moreover, reading and writing must actively be taught, usually by specialists, and evidence for a youthful critical period when this is easier than otherwise is lacking. Both, however, transform an individual's perception of the world, and for this reason Dr Patel refers to them as "transformative technologies". 相反，写作学习就是长期的挣扎，很多人即便有此机会，也未必掌握技巧。换句话说，阅读障碍非常常见。更甚者，读写需要积极教导，通常需要专家，而且没有明确证据表明，年轻时有一段特别时期教授读写相对容易。读写都改变个人的世界观，因此帕特尔博士称之为"变革性技术"。 In difficulty of learning, music lies somewhere in between speaking and writing. Most people have some musical ability, but it varies far more than their ability to speak. Dr Patel sees this as evidence to support his idea that music is not an adaptation in the way that language is, but is, instead, a transformative technology. However, that observation also supports the idea that sexual selection is involved, since the whole point is that not everyone will be equally able to perform, or even to learn how to do so. 从学习难度上看，音乐在说话和写作的中间地带。大部分人都有些音乐能力，但这种能力比说话能力的不确定性要大得多。帕特尔博士认为这证明了自己的观点：音乐并非同语言一样，是一种适应能力，而是一种变革性技术。然而，这同样证明，性选择也在其中扮演了角色，因为音乐并非所有人都有相同的表演能力，甚至学习能力。 Do they know it's Christmas? 他们知道是圣诞节吗？ What all of these hypotheses have in common is the ability of music to manipulate the emotions, and this is the most mysterious part of all. That some sounds lead to sadness and others to joy is the nub of all three hypotheses. The singing lover is not merely demonstrating his prowess; he also seeks to change his beloved's emotions. Partly, that is done by the song's words, but pure melody can also tug at the heartstrings. The chords of martial music stir different sentiments. A recital of the Monteverdi Vespers or a Vivaldi concerto in St Mark's cathedral in Venice, the building that inspired Gould to think of the non-role of spandrels, generates emotion pure and simple, disconnected from human striving. 这些假说的共通之处在于，都承认音乐驾驭情绪的能力，这最让人不解。某些声音会让人难过，有些会给人带来愉悦，在三个假说中都是要点。爱人歌唱，并非仅仅是表现自己的能力，同时也在试图改变所爱之人的情绪。这一部分是歌词的功效，但纯旋律也可以触动心弦。军乐可以激发不同的情感。在威尼斯圣马可大教堂中吟唱蒙特威尔第的晚祷，抑或维瓦尔第的协奏曲都能引发纯净而简单的情感，无关人类繁衍。而正是在圣马可大教堂，古尔德产生了拱肩无用的灵感。 This is an area that is only beginning to be investigated. Among the pioneers are Patrik Juslin, of Uppsala University, and Daniel Vastfjall, of Gothenburg University, both in Sweden. They believe they have identified six ways that music affects emotion, from triggering reflexes in the brain stem to triggering visual images in the cerebral cortex. 这个领域的研究刚刚开始。先驱者包括乌普萨拉大学的帕特里克•尤斯林和哥德堡大学的丹尼尔•法斯特加尔，两人都在瑞士。他们认为已经找到了音乐影响情感的六种方式，从初级的在脑干中引发反射，到高级的在大脑皮层中触发视觉图像。 Such a multiplicity of effects suggests music may be an emergent property of the brain, cobbled together from bits of pre-existing machinery and then, as it were, fine-tuned. So, ironically, everyone may be right―or, at least partly right. Dr Pinker may be right that music was originally an accident and Dr Patel may be right that it transforms people's perceptions of the world without necessarily being a proper biological phenomenon. But Dr Miller and Dr Dunbar may be right that even if it originally was an accident, it has subsequently been exploited by evolution and made functional. 影响的多元性显示，音乐可能是大脑的应变特性，是由预先存在的机制拼凑起来，而后经过调整。因此讽刺的是，可能大家都没错――至少部分正确。平克博士认为音乐最初是一种偶然或许没错，帕特尔博士认为音乐改变人们对世界的感知，却并不严格属于生理现象，也可能正确。但米勒和邓巴博士说，即便音乐最初是偶然，随后经过演变得以利用，并成为工具，也不无道理。 Part of that accident may be the fact that many natural sounds evoke emotion for perfectly good reasons (fear at the howl of a wolf, pleasure at the sound of gently running water, irritation and mother-love at the crying of a child). Sexually selected features commonly rely on such pre-existing perceptual biases. It is probably no coincidence, for instance, that peacocks' tails have eyespots; animal brains are good at recognising eyes because eyes are found only on other animals. It is pure speculation, but music may be built on emotions originally evolved to respond to important natural sounds, but which have blossomed a hundred-fold. 意外的发生，可能部分是因为许多大自然中的声音有充足理由激发情感（听到狼嚎的恐惧，听到温和流水声的愉悦，还有听到婴儿啼哭的愤怒和母性爱怜）。性选择的特征一般都基于这些预先存在的感知差别。孔雀尾巴上的眼状斑点，可能并非偶然：动物大脑善于识别眼睛，因为眼睛只有在其他动物身上才可见到。这仅仅是猜测，但很可能，音乐的情感基础起先是为对重要的自然声音做出回应，却得以长足发展。 The truth, of course, is that nobody yet knows why people respond to music. But, when the carol singers come calling, whether the emotion they induce is joy or pain, you may rest assured that science is trying to work out why. 当然事实上，目前无人知晓为什么人们会对音乐做出反应。颂歌歌手开始演唱时，不管他们是带着愉悦还是悲伤，您都大可放心，科学会努力给出一个答案。 from PRINT EDITION | Christmas Specials

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