经济学人64:双胞胎母亲更幸福

 　　Mothers of twins do not just get twice the bundle of joy—they are also healthier than other mothers

　　拥有双胞胎的母亲不仅能得到双份的快乐，而且她们会比其她母亲更健康。

　　THROUGHOUT history, twins have provoked mixed feelings. Sometimes they were seen as a curse—an unwanted burden on a family’s resources. Sometimes they were viewed as a blessing¹, or even as a sign of their father’s superior virility². But if Shannen Robson and Ken³ Smith, of the University of Utah, are right, twins have more to do with their mother’s sturdy constitution than their father’s sexual power.

　　在历史上，对待双胞胎有着复杂的感情。有时，他们被视为祸根--家庭中不受欢迎的负担。有时，他们被视为祝福，或作为他们父亲拥有更好的性能力的一个标志。但如果犹他大学的夏侬.罗布森和肯.史密斯是正确的，那么双胞胎为他们的母亲那健壮的体格所做的比为他们的父亲的性能力方面所做的更多。

　　At first blush, this sounds an odd idea. After all, bearing and raising twins is taxing, both for the mother and for the children. Any gains from having more than one offspring at a time might be expected to be like higher infant and maternal⁴ mortality rates. On this view, twins are probably an accidental by-product⁵ of a natural insurance policy against the risk of losing an embryo⁶ early in gestation⁷. That would explain why many more twins are conceived than born, and why those born are so rare (though more common these days, with the rise of IVF). They account for between six and 40 live births per 1,000, depending on where the mother lives.

　　乍看之下，这好像听起来好像是一个奇怪的想法，毕竟对于母亲和孩子，生产和抚养双胞胎是很费力的。每次从多于一个孩子那里获得的比期望的更多，通常会伴随着较高的婴儿死亡率和母亲死亡率。根据这种观点，双胞胎很可能是一次在怀孕期间用自然保障方式防止流产的意外的副产品。这样就能解释为何双胞胎怀的比生的多，而且为什么生的会这么少（虽然现在更多的运用试管受精已经很平常）。他们解释说每1000个中成活率在6到40之间，这要根据母亲生活的地方。

　　Dr Robson and Dr Smith, however, think that this account has got things the wrong way round. Although all women face a trade-off between the resources their bodies allocate⁸ to reproduction and those reserved for the maintenance of health, robust⁹ women can afford more of both than frail¹⁰ ones. And what surer way to signal robustness¹¹ than by bearing more than one child at a time? In other words, the two researchers conjectured¹², the mothers of twins will not only display greater overall reproductive success, they will also be healthier than those who give birth only to singletons.

　　然而，罗布森博士和史密斯博士认为这个解释是事情处于错误中。尽管许多女人面临着一个权衡，那就是在身体分配给生育所需的资源和保留给保持身体健康所需营养之间权衡。强健的母亲可能比瘦弱的母亲提供的更多。而且能有什么比健壮的母亲生育多于一个孩子更有说服力呢？换言之，这两位调查者推测，双胞胎的母亲不仅更好的展示了整体的生育成功，也会比只生一个孩子的母亲更健康。

　　Alas¹³, pinning down evolved relationships between fertility and health is tricky¹⁴. Modern medicine and the pampering¹⁵ effects of economic growth mean that, these days, women everywhere give birth to fewer children than they did in the distant evolutionary¹⁶ past, when human bodies and physiology¹⁷ were forged—even as more of the offspring they do bear survive into adulthood¹⁸. In Europe and North America this demographic transition began in earnest around 1870.

　　唉，控制生育和保持健康之间的关系是很难的。现代医学和经济的发展精心呵护的结果是，当人体和生理机能被伪造，这个时候的女性无论在哪里都会比处在以前缓慢发展时期的女性生的孩子要少，因为她们生的孩子大部分能活到成年。在欧洲和北美这个人口过渡开始于1870年左右。

　　One way round this is to look at records gathered before the demographic transition began. The problem is that few authorities then kept tabs diligently¹⁹ enough to provide adequate fodder²⁰ for statistical²¹ analysis. One exception was Utah, a state largely settled in its early days by Mormons, who have always taken such matters seriously. As a result, Utah’s Pedigree and Population Resource, a database of which Dr Smith is the director, contains 1.6m genealogical records for people in the state from the early 1800s to the 1970s.

　　围绕着寻找记录及合并的方法要在人口过渡开始前完成。这个问题是只有很少的当局会勤奋的为统计分析提供足够的材料保持制表符。一个例外是犹他州，在早期有摩门教徒定居在此，他们总是严肃的对待事情。结果，在史密斯博士作为主管的一个数据库中，犹他州的血统和人口资源包括160万份在早期的1800世纪到1970世纪中居住于此的居民的家谱记录。

　　To test their theory that the bearers of twins are supermums, Dr Robson and Dr Smith scoured²² the records for women born between 1807 and 1899 who survived past the age of 50, when the menopause typically strikes. They excluded those married more than once, those widowed before they were 50 and also (this being Utah) those wives who were part of one of the polygamous marriages once legal among the state’s Mormon settlers. (In a study published earlier this year, Dr Smith and his colleagues found that the more wives a Mormon woman had to compete with for her husband’s attentions, the fewer children she was likely to produce.) This left them with some 59,000 women, around 4,600 of whom had given birth to twins at least once.

　　为了检验他们关于双胞胎母亲是超级妈妈的说法罗伯森博士和史密斯博士搜集了关于超过50岁的更年期正常来临并在1807年到1899年进行生产的妇女的资料。她们只结过一次婚，在50岁以前就守寡并且这些妻子是一夫多妻制婚姻的一部分，而这在这一地区的摩门教徒中是合法的。（今年早期发布的一项研究表明，史密斯博士和他的同事发现在众多妻子中，一个摩门妇女不得不为了吸引丈夫的关注而竞争，这样她很可能会生更少的孩子。）这样的妇女大约有59000名，其中4600名至少一次的生产双胞胎。

　　To assess the effects of the demographic transition, the two researchers split the sample into women born before 1870 and those born in or after it. The results, just published in the Proceedings²³ of the Royal Society, confirm their hypothesis. Mothers of twins in the pre-1870 batch²⁴ gave birth, on average, to 1.9 more children than the mothers of singletons. Those in the post-1870 batch had 2.3 more. More importantly, from an evolutionary point of view, more of their children made it to maturity²⁵. The mothers of twins in the pre-1870 batch had 1.24 more children who survived past the age of 18 than did other mothers. After that date the figure was 1.56.

　　为了评估人口过渡的影响，这两名研究员分头对在1870年前和在这时及之后进行生产的妇女进行取样。结果公布在英国皇家学会学报上以证明他们的假说。在1870年前生产双胞胎的母亲平均比生一个的多生1.9个孩子。这在1870年后就变为多于2.3个了。更重要的是，从一个逐渐发展的角度来看，她们的孩子会更成熟。比起其她母亲来说，在1870年以前生育双胞胎的母亲会有多于1.24个孩子，这些孩子更能活到18岁。之后这个数据变成了1.56。

　　Of course, having twins automatically increases a mother’s lifetime fertility by one, relative to her number of pregnancies²⁶. But, since few women have twins more than once, the data imply that mothers of twins are more productive, even ignoring that effect. Moreover, they also outperformed the mothers of singletons on a range of other reproductive measures, including intervals²⁷ between births (shorter) and the age at which they gave birth to their last child (older).

　　当然，拥有双胞胎无意识的增强了母亲一生的生育力，这也和母亲的怀孕时间有关。但是如果很少妇女能多于一次的生产双胞胎，那么数据显示双胞胎的母亲拥有更好的生育力，甚至可忽视其影响。此外，她们也超过一个母亲的其她生育价值，包括生育之间的间歇和生育最后一个孩子的年龄。

　　Most strikingly, the pre-1870 group of mothers of twins actually lived longer than those who were not thus blessed. They were, in other words, simply healthier. This suggests that, in evolutionary terms at least, twins are far from a curse. On the contrary, they are indeed the mark of a supermum.

　　更明显的，在1870年前生产双胞胎的母亲实际上比没有这份祝福的要活得更长。换言之，她们是更健康的。这个建议说明，至少在进化过程中，双胞胎不是祸根，正好相反，他们却是超级母亲的标志。

1 blessing   

n.祈神赐福；祷告；祝福，祝愿

参考例句：

• The blessing was said in Hebrew.祷告用了希伯来语。
• A double blessing has descended upon the house.双喜临门。

2 virility   

n.雄劲，丈夫气

参考例句：

• He wanted his sons to become strong,virile,and athletic like himself.他希望他的儿子们能长得像他一样强壮、阳刚而又健美。
• He is a tall,virile man with rugged good looks.他是个身材高大、体魄健壮、相貌粗犷英俊的男子。

3 ken   

n.视野，知识领域

参考例句：

• Such things are beyond my ken.我可不懂这些事。
• Abstract words are beyond the ken of children.抽象的言辞超出小孩所理解的范围.

4 maternal   

adj.母亲的，母亲般的，母系的，母方的

参考例句：

• He is my maternal uncle.他是我舅舅。
• The sight of the hopeless little boy aroused her maternal instincts.那个绝望的小男孩的模样唤起了她的母性。

5 by-product   

n.副产品，附带产生的结果

参考例句：

• Freedom is the by-product of economic surplus.自由是经济盈余的副产品。
• The raw material for the tyre is a by-product of petrol refining.制造轮胎的原材料是提炼汽油时产生的一种副产品。

6 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

7 gestation   

n.怀孕；酝酿

参考例句：

• The gestation period can be anything between 95 and 150 days.妊娠期从95天至150天不等。
• This film was two years in gestation.这部电影酝酿了两年。

8 allocate   

vt.分配，分派；把…拨给；把…划归

参考例句：

• You must allocate the money carefully.你们必须谨慎地分配钱。
• They will allocate fund for housing.他们将拨出经费建房。

9 robust   

adj.强壮的，强健的，粗野的，需要体力的，浓的

参考例句：

• She is too tall and robust.她个子太高，身体太壮。
• China wants to keep growth robust to reduce poverty and avoid job losses,AP commented.美联社评论道，中国希望保持经济强势增长，以减少贫困和失业状况。

10 frail   

adj.身体虚弱的；易损坏的

参考例句：

• Mrs. Warner is already 96 and too frail to live by herself.华纳太太已经九十六岁了，身体虚弱，不便独居。
• She lay in bed looking particularly frail.她躺在床上，看上去特别虚弱。

11 robustness   

坚固性，健壮性；鲁棒性

参考例句：

• There were other reasons for concern about the robustness of an economic recovery. 人们还有其他一些原因对经济恢复的健全程度表示关心。 来自英汉非文学 - 政府文件
• Robustness analysis attracts more and more attention in these years. 鲁棒性分析是近几年学术界较为关注的问题。 来自互联网

12 conjectured   

推测，猜测，猜想( conjecture的过去式和过去分词 )

参考例句：

• The old peasant conjectured that it would be an unusually cold winter. 那老汉推测冬天将会异常地寒冷。
• The general conjectured that the enemy only had about five days' supply of food left. 将军推测敌人只剩下五天的粮食给养。

13 alas   

int.唉(表示悲伤、忧愁、恐惧等)

参考例句：

• Alas!The window is broken!哎呀！窗子破了！
• Alas,the truth is less romantic.然而，真理很少带有浪漫色彩。

14 tricky   

adj.狡猾的，奸诈的；(工作等)棘手的，微妙的

参考例句：

• I'm in a rather tricky position.Can you help me out?我的处境很棘手，你能帮我吗？
• He avoided this tricky question and talked in generalities.他回避了这个非常微妙的问题，只做了个笼统的表述。

15 pampering   

v.纵容，宠，娇养( pamper的现在分词 )

参考例句：

• But you need to make an appointment because these people are usually very busy pampering pets. 但是你需要先预约，因为这些人通常都在忙于照顾宠物们。 来自超越目标英语 第2册
• He had been pampering, and coaxing, and indulging that individual all his life. 他一生都在姑息、迁就、纵容那家伙。 来自辞典例句

16 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

17 physiology   

n.生理学，生理机能

参考例句：

• He bought a book about physiology.他买了一本生理学方面的书。
• He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。

18 adulthood   

n.成年，成人期

参考例句：

• Some infantile actions survive into adulthood.某些婴儿期的行为一直保持到成年期。
• Few people nowadays are able to maintain friendships into adulthood.如今很少有人能将友谊维持到成年。

19 diligently   

ad.industriously;carefully

参考例句：

• He applied himself diligently to learning French. 他孜孜不倦地学法语。
• He had studied diligently at college. 他在大学里勤奋学习。

20 fodder   

n.草料；炮灰

参考例句：

• Grass mowed and cured for use as fodder.割下来晒干用作饲料的草。
• Guaranteed salt intake, no matter which normal fodder.不管是那一种正常的草料，保证盐的摄取。

21 statistical   

adj.统计的，统计学的

参考例句：

• He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
• They're making detailed statistical analysis.他们正在做具体的统计分析。

22 scoured   

走遍（某地）搜寻（人或物）( scour的过去式和过去分词 )； （用力）刷； 擦净； 擦亮

参考例句：

• We scoured the area for somewhere to pitch our tent. 我们四处查看，想找一个搭帐篷的地方。
• The torrents scoured out a channel down the hill side. 急流沿着山腰冲刷出一条水沟。

23 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

24 batch   

n.一批(组，群)；一批生产量

参考例句：

• The first batch of cakes was burnt.第一炉蛋糕烤焦了。
• I have a batch of letters to answer.我有一批信要回复。

25 maturity   

n.成熟；完成；(支票、债券等)到期

参考例句：

• These plants ought to reach maturity after five years.这些植物五年后就该长成了。
• This is the period at which the body attains maturity.这是身体发育成熟的时期。

26 pregnancies   

怀孕，妊娠( pregnancy的名词复数 )

参考例句：

• Since the wartime population needed replenishment, pregnancies were a good sign. 最后一桩倒不失为好现象，战时人口正该补充。
• She's had three pregnancies in four years. 她在四年中怀孕叁次。

27 intervals   

n.[军事]间隔( interval的名词复数 )；间隔时间；[数学]区间；（戏剧、电影或音乐会的）幕间休息

参考例句：

• The forecast said there would be sunny intervals and showers. 预报间晴，有阵雨。
• Meetings take place at fortnightly intervals. 每两周开一次会。