新世纪研究生公共英语教材B 11 13单元

1、b:第九单元animal emotionslaura tangleysheer joy. romantic love. the pain of mourning. scientists say pets and wild creatures have feelings, too.1.swimming off the coast of argentina, a female right whale singles out just one of the suitors that are hotly pursuing her. after mating, the two cetaceans lin

2、ger side by side, stroking one another with their flippers and finally rolling together in what looks like an embrace. the whales then depart, flippers touching, and swim slowly side by side, diving and surfacing in perfect unison until they disappear from sight.2. in tanzania, primatologists studyi

3、ng chimpanzee behavior recorded the death of flo, a troops 50-year-old matriarch. throughout the following day, flos son, flint, sits beside his mothers lifeless body, occasionally taking her hand and whimpering. over the next few weeks, flint grows increasingly listless, withdrawing from the troop

4、despite his siblings efforts to bring him backand refusing food. three weeks after flos death, the formerly healthy young chimp is dead, too.3.a grief-stricken chimpanzee? leviathans in love? most people, raised on disney versions of sentient and passionate beasts, would say that these tales, both t

5、rue, simply confirm their suspicions that animals can feel intense, humanlike emotions. for their part, the nations 61 million pet owners need no convincing at all that pet dogs and cats can feel angry, morose, elated even jealous or embarrassed. recent studies, in fields as distant as ethology and

6、neurobiology, are supporting this popular belief. other evidence is merely anecdotal, especially for pets dogs that become depressed, or even die, after losing a beloved companion, for instance. but the anecdote or case study in scientific parlance has now achieved some respectability among research

7、ers who study animal behavior. as university of colorado biologist marc bekoff says, “the plural of anecdote is data.”4.still, the idea of animals feeling emotions remains controversial among many scientists. researchers skepticism is fueled in part by their professional aversion to anthropomorphism

8、, the very nonscientific tendency to attribute human qualities to non-humans. many scientists also say that it is impossible to prove animals have emotions using standard scientific methods repeatable observations that can be manipulated in controlled experiments leading them to conclude that such f

9、eelings must not exist. today, however, amid mounting evidence to the contrary, “the tide is turning radically and rapidly,” says bekoff, who is at the forefront of this movement.5.even the most strident skeptics of animal passion agree that many creatures experience fear which some scientists defin

10、e as a “primary” emotion that contrasts with “secondary” emotions such as love and grief. unlike these more complex feelings, fear is instinctive, they say, and requires no conscious thought. essential to escape predators and other dangers, fear and its predictable flight, fight, or freeze responses

11、 seems to be hard-wired into many species. young geese that have never before seen a predator, for example, will run for cover if a hawk-shaped silhouette passes overhead. the shape of a nonpredatory bird, on the other hand, elicits no such response.6.but beyond such instinctual emotions and their p

12、redictable behavioral responses, the possibility of more complex animal feelings those that entail mental processing is difficult to demonstrate. “i cant even prove that another human being is feeling happy or sad,” says bekoff, “but i can deduce how theyre feeling through body language and facial e

13、xpression.” as a scientist who has conducted field studies of coyotes, foxes, and other canines for the past three decades, bekoff also believes he can accurately tell what these animals are feeling by observing their behavior. he adds that animal emotions may actually be more knowable than those of

14、 humans, because they dont “filter” their feelings the way we do.7. yet because feelings are intangible, and so tough to study scientifically, “most researchers dont even want to talk about animal emotions,” says jaak panksepp, a neuroscientist at bowling green state university in ohio and author of

15、 affective neuroscience. within his field, panksepp is a rare exception, who believes that similarities between the brains of humans and other animals suggest that at least some creatures have true feelings. “imagine where wed be in physics if we hadnt inferred whats inside the atom,” says panksepp.

16、 “most of what goes on in nature is invisible, yet we dont deny that it exists.”8. the new case for animal emotions comes in part from the growing acceptability of field observations, particularly when they are taken in aggregate. the latest contribution to this body of knowledge is a new book, the

17、smile of a dolphin, which presents personal reports from more than 50 researchers who have spent their careers studying animals from cats, dogs, bears, and chimps to birds, iguanas, and fish. edited by bekoff, who says it will finally “legitimize” research on animal emotions, the volume has already

18、garnered scientific attention, including a smithsonian institution symposium on the subject.9. one of the most obvious animal emotions is pleasure. anyone who has ever held a purring cat or been greeted by a bounding, barking, tail-wagging dog knows that animals often appear to be happy. beastly joy

19、 seems particularly apparent when the animals are playing with one another or sometimes, in the case of pets, with people.10.virtually all young mammals, as well as some birds, play, as do adults of many species such as our own. young dolphins, for instance, routinely chase each other through the wa

20、ter like frolicsome puppies and have been observed riding the wakes of boats like surfers. primatologist jane goodall, who has studied chimpanzees in tanzania for four decades, says that chimps “chase, somersault, and pirouette around one another with the abandon of children.” in colorado, bekoff on

21、ce watched an elk race back and forth across a patch of snow even though there was plenty of bare grass nearby leaping and twisting its body in midair on each pass. though recent research suggests that play may help youngsters develop skills needed in adulthood, bekoff says theres no question that i

22、ts also fun. “animals at play are symbols of the unfettered joy of life,” he says11. grief also seems to be common in the wild, particularly following the death of a mate, parent, offspring, or even close companion. female sea lions witnessing their pups being eaten by killer whales are known to act

23、ually wail. when a goose, which mates for life, loses its partner, the birds head and body droop dejectedly. goodall, who saw the young chimp flint starve after his mother died, maintains that the animal “died of grief.”12. elephants may be natures best-known mourners. scientists studying these behe

24、moths have reported countless cases of elephants trying to revive dead or dying family members, as well as standing quietly beside an animals remains for many days, periodically reaching out and touching the body with their trunks. kenyan biologist joyce poole, who has studied african elephants sinc

25、e 1976, says these animals behavior toward their dead “leaves me with little doubt that they experience deep emotions and have some understanding about death.”13.but theres “hard” scientific evidence for animal feelings as well. scientists who study the biology of emotions, a field still in its infa

26、ncy, are discovering many similarities between the brains of humans and other animals. in animals studied so far, including humans, emotions seem to arise from ancient parts of the brain that are located below the cortex, regions that have been conserved across many species throughout evolution.14.t

27、he most important emotional site identified so far is the amygdala, an almond-shape structure in the center of the brain. working with rats, neuroscientists have discovered that stimulating a certain part of the amygdala induces a state of intense fear. rats with damaged amygdalas, on the other hand

28、, do not show normal behavioral responses to danger (such as freezing or running) or the physiological changes associated with fear higher heart rate and blood pressure, for example.15. in humans, brain-imaging studies show that when people experience fear, their amygdalas, too, are activated. and j

29、ust like the rats, people whose amygdalas are damaged by accident or disease seem unable to be afraid when the situation warrants it. in humans and rats, at least, amygdalas are “basically wired the same way,” says new york university neuroscientist joseph ledoux, whose lab conducted much of the rat

30、 research. he adds that beyond fear, “the evidence is less clear, but the amygdala is implicated in other emotions as well.”16.the case for animal emotions is also bolstered by recent studies of brain chemistry. steven siviy, a behavioral neuroscientist at gettysburg college in pennsylvania, has fou

31、nd that when rats play, their brains release copious amounts of dopamine, a neurochemical that is associated with pleasure and excitement in humans. in one experiment, siviy placed pairs of rats in a distinctive plexiglass chamber and allowed them to play. after a week, he could put one animal alone

32、 in the chamber and, anticipating its upcoming play session, it would become “very active, vocalizing, and pacing back and forth with excitement.” but when siviy gave the same animal a drug that blocks dopamine, all such activity came to a halt. neuroscientist panksepp has found evidence that rats a

33、t play also produce opiateschemicals that, like dopamine, are thought to be involved with pleasure in people.17.another chemical, the hormone oxytocin, is associated with both sexual activity and maternal bonding in people. it is released, for example, when mothers are nursing their infants. now it

34、looks as though the same hormone affects attachment among animals, at least in the case of a mouselike rodent called the prairie vole. to investigate oxytocins role in social bonding, university of maryland neuroscientist c. sue carter targeted the vole because it is one of the few mammal species kn

35、own to be monogamous. she found that females, who normally spend about a day selecting a mate from a pool of eager males, will choose one within an hour often the first male they see if they have first received an injection of oxytocin. voles given a drug that blocks oxytocin, however, will not sele

36、ct a mate, no matter how much time they have. carter concludes that pair bonding in voles relies at least in part on oxytocin, which produces behavior that looks much like people who are “falling in love.”18.but is it love, really? bernd welsig, the texas a&m university biologist who observed amorou

37、s right whales off the coast of argentina, believes that, as a scientist, “i should probably call this event a mere example of an alternative mating strategy. “ but welsig still entertains the possibility that the cetaceans behaved the way they did because “they were the right right whales for each

38、other.”19. skeptics remain unconvinced. “a whale may behave as if its in love, but you cant prove what its feeling, if anything,” says neuroscientist ledoux, author of the emotional brain. he maintains that the question of feelings boils down to whether or not animals are conscious. and though anima

39、ls “may have snapshots of self-awareness,” he says, “the movie we call consciousness is not there.” richard davidson, a neuroscientist at the university of wisconsin-madison, agrees that higher primates, including apes and chimps, are the only animals that have demonstrated self-consciousness so far

40、. still, he believes that there are other creatures that “may at least have antecedents of feelings.”20. or probably more, say bekoff and his colleagues. their most convincing argument, perhaps, comes from the theory of evolution, widely accepted by biologists of all stripes. citing similarities in

41、the brain anatomy and chemistry of humans and other animals, neuroscientist siviy asks: “if you believe in evolution by natural selection, how can you believe that feelings suddenly appeared, out of the blue, with human beings?” goodall says scientists who use animals to study the human brain, then

42、deny that animals have feelings, are “illogical.”21. in the end, what difference does it really make? according to many scientists, resolving the debate over animal emotions could turn out to be much more than an intellectual exercise. if animals do indeed experience a wide range of feelings, it has

43、 profound implications for how humans and animals will interact in the future. bekoff, for one, hopes that greater understanding of what animals are feeling will spur more stringent rules on how animals should be treated, everywhere from zoos and circuses to farms and backyards.22. but if there is c

44、ontinuity between the emotional lives of humans and other animals, where should scientists draw the line? michel cabanac, a physiologist at laval university in quebec, believes that consciousness arose when animals began to experience physical pleasure and displeasure. in experiments with iguanas, h

45、e discovered that the animals show physiological changes that are associated with pleasure in mammals a rise in body temperature and heart rate whereas frogs and fish do not. he proposes that emotions evolved somewhere between the first amphibians and reptiles. yet even enthusiasts dont ascribe emot

46、ions to the very bottom end of the food chain. says bekoff: “were not going to talk about jealous sponges and embarrassed mosquitoes.”动 物 的 情 感 劳拉坦利非常的开心。浪漫的爱情。悲恸的哀悼。科学家说宠物和野生动物也有情感。1.一只在阿根廷海岸附近的水域中游动的露脊鲸，在众多热烈追求她的求偶者中只选出一名幸运儿。“完婚”之后，两头露脊鲸并排在水中徜徉，它们用鳍肢相互抚摩，最后又一起在水中滚动，看上去就像在互相拥抱。然后，两头露脊鲸开始游向远方，鳍肢相互触摸

47、，慢慢并排游动，一会潜入水中，一会又浮出水面，它们动作完美和谐，直至最终在视线中消失。2.在坦桑尼亚，致力于研究黑猩猩行为的灵长类动物学家记录了一个黑猩猩群落中享年50岁的“女族长”弗洛死后发生的一些事情。弗洛的儿子弗林特第二天一整天都坐在母亲的尸体旁边，有时还会抓住她的手发出几声呜咽。在此后的几个星期里，弗林特的情绪越来越低落，他离群索居并且不再进食，尽管他的兄弟姐妹设法想让他回到群体中来。终于，在弗洛死后的第3个星期，原本年轻健康的黑猩猩弗林特也死了。3.悲伤过度的黑猩猩？坠入情网的海洋巨兽？很多人，由于深受迪斯尼卡通片中感性多情的动物形象的影响，会说这两个真实的故事更加证实了他们认为动物

48、有人类般强烈情感的看法。从他们的角度来看，全国六千一百万拥有宠物的人完全不需要提供什么证据来证实宠物狗和宠物猫会生气、郁闷、得意洋洋甚至会嫉妒或困窘。最近在动物行为学和神经生物学之类的边缘学科的研究证实了这种普遍看法。其他的证据只是些轶事趣闻，特别是一些有关宠物的事，例如狗会在失去心爱的同伴后，变得沮丧，甚至死去。但是轶事趣闻或用科学的术语称之为案例研究现在已经获得了研究动物行为的研究人员的重视。正如科罗拉多大学的生物学家马克贝科夫所说：“大量的轶事趣闻就是数据。”4.但是，许多科学家仍然对动物也有情感的观点持有异议。研究人员之所以会表示怀疑，部分原因是他们出于职业习惯讨厌拟人论，因为他们认为

49、这是一种将人类的特性强加在非人类生物身上的毫无科学根据的主观倾向。许多科学家还认为用标准的科学方法（在受控实验环境下可进行重复观察）是无法证明动物是有情感的这使他们得出结论，认为这些所谓的动物情感一定不存在。但是动物情感论的积极倡导者贝科夫指出，如今面对越来越多的相反证据，“这场运动的潮流正在根本性地迅速转向”。 5.甚至连那些对动物情感论持绝对怀疑态度的人也承认，许多动物有恐惧感一些科学家认为，恐惧是与爱和悲伤等“中级”情感相对的“初级”情感。他们认为，与较为复杂的“中级”情感相比，恐惧是一种本能，它不需要任何有意识的思维。恐惧及其可以预见的逃跑、搏斗或者呆住不动的反应，是逃避食肉动物和其他

50、危险所必需的，它看起来好像是许多动物与生俱来的本领。例如，以前从未见过食肉动物的小鹅如果看到形状像老鹰一样的黑影从头顶掠过就会马上跑去寻找藏身处。而另一方面，非食肉鸟的形状就不会引发这样的反应。6.但是，除了这些具有本能性质的情感及其可以预见的行为反应之外，科学家很难证明动物可能拥有更为复杂的情感，即那些必需有心理活动过程的情感。贝科夫说：“我甚至不能证实另一个人是快乐还是悲伤，但我可以通过肢体语言和脸部表情推论出他（们）的情感。”作为对丛林狼、狐狸及其他犬科动物进行长达30年实地研究的科学家，贝科夫还认为自己可以通过观察这些动物的行为准确地说出他们的感受。他又指出，了解动物的感情事实上可能比

51、了解人类的感情更容易，因为它们不会像人类那样对情感进行“过滤”。 7.但是情感神经学一书的作者、俄亥俄州立堡林格林大学神经学学家雅克潘克塞普指出，因为感情是一种无形的东西，而且很难用科学手段进行研究，“所以大多数研究人员甚至不愿意谈论动物情感问题”。 而潘克塞普在他的研究领域里是一个非常少见的例外，他认为，人类大脑和其他动物大脑之间的相似之处表明，至少某些动物拥有真正的感情。潘克塞普说：“想象一下，如果我们没有推测出原子中的物质，那我们的物理学会是什么样的。在自然中大部分事物的进展是看不见的，然而我们并不否认它的存在。”8.对动物情感的接受之所以会出现新的局面，部分原因是有越来越多的人愿意接受

52、研究人员取得的实地观察结果，特别是当从总体角度看待这些结果时。一本名为海豚的微笑的新书为增加动物情感方面的知识做出了新的贡献，该书收录了50多名研究人员撰写的个人报告。这些研究人员将自己的整个职业生涯都倾注在对猫、狗、熊、黑猩猩、鸟、鬣蜥和鱼等动物的研究。该书的编辑贝科夫认为，这本书最终会使动物情感的研究变得“合法”。而这本新书也的确引起了科学界的关注其中，史密森氏学会就举行了一次以动物情感为主题的研讨会。9.动物最显而易见的情感之一就是快乐。养过会发出咕噜声的小猫，或者受到过边跳边叫、摇着尾巴的小狗欢迎的人，就知道动物看起来常常十分快乐。动物相互嬉戏的时候，或有时跟人一起玩耍时（就宠物而言）

53、，它们的快乐好像会变得特别明显。10.事实上，所有幼小的哺乳动物和某些鸟类都会嬉戏玩耍，正如很多种类的成年动物一样，包括人类也是如此。例如，小海豚就像爱闹着玩的小狗，常常在水中互相追逐。人们常常看到它们像冲浪运动员般追逐在船后的浪花上。灵长类动物学家简古多尔曾经在坦桑尼亚对黑猩猩进行了40年的研究，他说黑猩猩会“孩子般尽情地追逐、翻跟头、踮着脚尖相互旋转”。有一次，贝科夫在科罗拉多观察到一只麋鹿来来回回地跑着穿越一小块雪地，尽管边上就有无雪的草地。它每次跨跃都要跳起来并在半空扭动着躯体。贝科夫说虽然近来的研究表明嬉戏玩耍会帮助小动物培养成年所需要的技巧，而毫无疑问的是，它也会带来快乐。他还说：

54、“玩耍的动物是无拘无束生活快乐的象征。”11.在野生动物中，悲伤似乎也很常见，尤其是在失去了配偶、双亲、幼崽，甚至是亲密同伴的时候。比如，当母海狮目击了自己的小海狮被逆戟鲸吃掉时，会发出哀号。一生只有一个配偶的天鹅失去配偶时，会沮丧地垂着头和身体。古多尔亲眼看到小黑猩猩弗林特在母亲死后饿死，他坚持说小黑猩猩是“死于悲伤”。12.大象可能是大自然最著名的哀悼者了。研究这些庞然大物的科学家的报告中有大量的事实陈述了大象试图使死去的或将要死去的家庭成员复活，还会很多天静静地站在尸体旁，不时地伸出长鼻触动一下尸体。肯尼亚生物学家乔伊斯普尔从1976年以来就研究非洲大象，他说，这些动物对待死去的动物的行

55、为“让我几乎毫不怀疑地认为，它们体验着深切的感情并对死亡有所理解。”13.有一些“确凿的”科学证据也可以证明动物有感情。致力于情感生物学（一个新生的科学领域）研究的科学家发现，人脑与其它动物的大脑之间存在着许多相似之处。科学家在到目前为止对动物（包括人类）的研究发现，情感看起来好像是在大脑一些较为“古老”的区域中产生的，这些区域位于大脑皮层以下，它们在许多物种的进化过程中都得以保存下来。14.目前已经被科学家识别出来的最重要的情感区域，是大脑中的扁桃体，这是一个位于大脑中央的杏仁状结构。神经科学家通过在老鼠身上进行的实验，发现刺激扁桃体某个特定的部分会导致实验鼠处于一种极度恐惧的状态。在另一方

56、面，扁桃体遭到破坏的实验鼠在遇到危险时，既不会表现出正常的行为反应（比如呆住或者逃跑），也不会出现与恐惧联系在一起的生理变化如心跳加快和血压升高。15.利用成像技术对人脑进行的研究表明，当人类感到恐惧时，大脑中的扁桃核也会被激活。与实验鼠一样，由于意外事故或疾病而导致扁桃核受损的人似乎在面对危险时也无法感到恐惧。在实验室进行了大量鼠类研究的纽约大学神经学学家约瑟夫勒杜指出，至少人类和老鼠的扁桃核“基本上采用了相同的布线方式”。他又补充说，除恐惧外，“有证据表明，扁桃核与其他情感也有关系，但是这些证据不像证明扁桃核与恐惧有关的证据那样明确。”16. 动物情感论还得到了最近进行的大脑化学研究的支持

57、。宾夕法尼亚葛底斯堡学院行为神经科学家史蒂文西维发现，老鼠在玩耍的时候，它的大脑会释放出大量的多巴胺人类的快乐和兴奋等情感就与这种神经化学物质有关。在一项实验中，西维把一对对的实验鼠放在了特殊的树脂玻璃“房子”中，然后让它们尽情玩耍。一星期后，他又把一只实验鼠单独放在“房子”里，期待着马上就可以再好好地玩上一段时间的实验鼠变得“非常活跃，它不断地发出叫声并且兴奋地来回跑动”。但是当西维给这只实验鼠喂食了一种抑制多巴胺的药物以后，所有的此类活动都全部停止了。神经科学家潘克塞普已经找到证据证明，老鼠在玩耍的过程中体内还会产生多种鸦片剂科学家认为这些化学物质与多巴胺一样，也与人类的快乐情绪有关。17

58、.另一种化学物质荷尔蒙催产素与人类的性活动和母性有关。例如，母亲培育婴儿时体内就会释放出催产素。现在看来这种激素好像对动物之间的相互依恋也有影响，至少在一种与老鼠十分相似的啮齿类动物草原田鼠身上是这样。为了研究催产素对社会依附关系的作用，马里兰大学神经科学家c休卡特选择了草原田鼠作为她的研究对象，因为草原田鼠是人们已知的实行“一夫一妻制”的为数不多的几种哺乳动物之一。她发现母鼠一般会花一天的时间从一群热切的公鼠中挑选出一只配偶，但是如果它们在选择配偶之前注射了催产素的话，母鼠的择偶时间就会缩短为一小时而且常常会选择它们看见的第一只公鼠。然而，如果母鼠服食了催产素抑制药物，那么不论有多少时间它们

59、也不会选择配偶。卡特由此得出结论认为，雌雄田鼠之间亲密关系的形成至少部分原因是催产素，这种激素可以导致田鼠做出与“坠入爱河”的人非常相似的举动。18.但这真是爱情吗？曾经对生活在阿根廷附近海域的“多情”露脊鲸进行过观察的得克萨斯农业和机械大学生物学家贝恩德伍尔西格指出，作为一名科学家，“我很可能应该将露脊鲸的行为仅仅称作是“选择性的交配策略” 的一个例子”。但是他仍然认为，露脊鲸之所以会有这种行为表现也有可能是因为“它们相互之间情投意合”。19对动物情感论持怀疑态度的人仍然坚持自己的看法。情感大脑一书的作者，神经科学家勒杜指出：“鲸也许会做出好像他们正在恋爱的举动，但是你无法证明它的内心感受，即使鲸有这种感受的话。”他认为动物情感问题归根到底就是动物是否有意识的问题。他说，虽然动物“会有点滴的自我意识，但是我们所称的意识图像