研究者将一群志愿者分成了两组。他们向第一组的成员展示了一组相反性别的长得很漂亮或很帅的异性的照片，希望志愿者们“浮想联翩”。接着研究者要求他们每人写下关于自己和某张照片上的人的一次完美约会。而另一组的志愿者就没有这么幸运了，他们看到的是一组高楼大厦的图片，并要写一个关于天气的报告。然后研究人员要求参与者们做两件事情。第一件事情是要求他们想象自己在银行有5000美元。他们可以把其中一部分或者所有的钱花在各种奢侈品上，比如一辆新车、在餐馆的一次晚宴，或者去欧洲度假。第二件事情是，假设他们一月有60个小时的休闲时间，那么他们愿意花多少休闲时间去做志愿者工作。

研究结果正如研究人员预料的那样。在身处浪漫气氛的第一组成员中，男人们疯狂地想完全占有金钱。相反，女人们则把时间花在做志愿者工作上。但是女人们变得更加吝啬，而男人们仍然对财富少于他们的人很冷漠。同时，在另一组成员中，人们既不倾向于大肆挥霍，也没有做善事的偏好。基于这一结果，看起来不同性别的人实际上对于炫耀有不同的策略。此外，他们不会总是把他们的资源浪费在这些行为上。只有当吸引异性的时候，男人们才会花更多的钱，女人们才会更加乐于助人。





Unit 56


According to the new research appearing in the July 26 issue of The New England Journal of Medicine, obesity isn't just spreading; rather, it may be contagious between people, like a common cold. Researchers from Harvard and the University of California, San Diego, reviewed a database of 12,067 densely interconnected people——that is, a group that included many families and friends——who had all participated in a major American heart study between 1971 and 2003. The participants met with heart researchers every two to four years. It was that information the NEJM authors mined to explore obesity in the context of a social network.

According to their analysis, when a study participant's friend became obese, that first participant had a 57% greater chance of becoming obese himself. In pairs of people in which each identified the other as a close friend, when one person became obese the other had a 171% greater chance of following suit. James Fowler, study co-author and a political scientist at UC San Diego says that it's not just that people who share similar lifestyles become friends. He and co-author Nicholas Christakis of Harvard Medical School considered the possibility——and were surprised. For one thing, geographic distance between friends in the study seemed to have no impact: friends who lived a 5-hour drive apart and saw each other infrequently were just as influenced by each other's weight gains as those who lived close enough to share weekly take-out meals or pick-up basketball games. The best proof that friendship caused the weight gain, says Fowler, is that people were much more likely to pattern their own behavior on the actions of people they considered friends——but the relationship didn't work in the other direction. If you had named another person as a friend, and your friend became obese, than you were more than 50% more likely to get fat too. But if your friend had not named you as a mutual friend, and you became obese, it would have no significant impact on your friend's weight.

The obvious question is, Why? Spouses share meals and a backyard, but the researchers found a much smaller risk of gaining weight——a 37% increase——when one spouse became obese. Siblings share genes, but their influence, too, was much smaller, increasing each other's risk 40%. Fowler believes the effect has much more to do with social norms: whom we look to when considering appropriate social behavior. Having fat friends makes being fat seem more acceptable. “Your spouse may not be the person you look to when you're deciding what kind of body image is appropriate, how much to eat or how much to exercise,”Fowler says. Nor do we necessarily compare ourselves to our siblings. “We get to choose our friends,”Fowler says. “We don't get to choose our families.”

Fowler and Christakis say that the contagion-effect should hold just as much for weight loss as it does for weight gain. “I would hope this influences individuals to get friends and families involved in decisions about health,”Fowler says. After all, he says, a weight-loss plan may be more effective if the people closest to you are on board. And, if you're successful, your good health will help others achieve a healthy weight too. The impact extends not just to your friends, it turns out——but also to your friends' friends, and even to their friends.

注（1）：本文选自Economist；

注（2）：本文习题命题模仿对象为2002年真题Text 3。

1. The following are factors causing obesity according to the researchers, EXCEPT_______.

A) similar lifestyles among some people

B) geographical distance between friends

C) one's closest friend being fat

D) being mutual friend with fat guys

2. It can be inferred from the text that_______.

A) all the participants are connected with each other in a considerably large social network

B) it is a long-term study on which researchers spent years to study the contagion of obesity

C) researchers meet participants suffering heart diseases regularly and other participants irregularly

D) the study is based on a large and reliable database of another medical research

3. The experiment involves both family members and friends because_______.

A) researchers fail to find a more diverse and representative sample

B) researchers have different hypotheses for family members and freinds

C) researchers can easily find these people so as to conduct regular meetings in the long run

D) researchers can compare the results between the friends group and the family group

4. We can draw a conclusion from the text that_______.

A) when people choose friends, obesity comes as the first standard

B) the friends of a fat person must all be very fat

C) family plays a more important role of affecting obesity

D) the contagion-effect of obesity also sheds light on weight loss

5. From the text we can see the writer seems_______.

A) objective

B) optimistic

C) sensitive

D) gloomy





篇章剖析


本文就肥胖在人与人之间的传播这一问题展开了论述。第一段提出了话题，并说明了一项相关研究的背景和方法；第二段展示了研究结果，并结合实例进行说明；第三段讨论了家庭关系和朋友关系对于肥胖的不同影响及其原因；第四段指出了该研究的实用性以及研究者对肥胖传染效应的展望。





词汇注释


obesity /əʊˈbɪsɪti/ n. 肥胖，肥大

contagious /kənˈteɪdʒəs/ adj. 传染性的，会感染的

densely /ˈdensli/ adv. 密切地

take-out /ˈteɪkˌaut/ adj. 供应外卖食物的

spouse /spauz/ n. 配偶（指夫或妻）

norm /nɔːm/ n. 标准，规范





难句突破


Researchers from Harvard and the University of California, San Diego, reviewed a database of 12,067 densely interconnected people——that is, a group that included many families and friends——who had all participated in a major American heart study between 1971 and 2003.

主体句式：Researchers reviewed a database of 12,067 people.

结构分析：这个长句看似结构复杂，主要是因为其中有较多的修饰成分。两个破折号之间的句子是people的同位语，主要是对被调查者的身份进行补充说明，其中that is是同位语结构的标志；who引导的定语从句也是修饰people。

句子译文：来自哈佛大学和加州大学圣地亚哥分校的研究者查阅了1971年到2003年期间参与美国一项重要心脏研究的12,067位受访者的数据库，这些受访者之间大多都有亲密的关系，包括许多家庭成员和朋友。





题目分析


1. B 细节题。文章第二段指出地理上的远近对于肥胖问题没有什么影响，而A、C、D选项都可以在该段落中找到对应信息。

2. D 推理题。文章第一段中指出关于肥胖传染性的研究主要是基于另一个关于心脏病研究的数据，因而答案为D。A选项的错误原因在于并不是参与研究的所有成员都是互相联系着的，但他们都是以家庭成员或者朋友的身份参加研究的。B选项的错误原因在于肥胖传染性的研究并不是一个长期研究，而该研究的数据来源于另一个长期研究。C选项的错误原因在于研究者和所有的参与者都是定期见面。

3. D 细节题。文章第三段比较了家人和朋友对于肥胖现象的影响，可以看出研究人员研究这两组人的目的在于比较两组人对于肥胖的相互影响是否会有不同的效果。

4. D 推理题。文章最后一段指出，该研究发现的肥胖传染现象也可能促使相反效果的产生，即一个人减肥会影响他的亲人朋友，从而使得减肥现象也得以传播，使胖人们的体重向更健康的趋势发展。

5. A 情感态度题。虽然文章最后指出研究者对其研究结果持非常乐观的态度，但综观全文，作者的描述一直很客观，没有加入个人见解，因此答案为A。





参考译文


7月26日出版的《新英格兰医学杂志》刊登的一项新研究认为，肥胖的人不仅仅在越来越多，更可怕的是，肥胖会像感冒一样，在人与人之间传播。来自哈佛大学和加州大学圣地亚哥分校的研究者查阅了1971年到2003年期间参与美国一项重要心脏研究的12,067位受访者的数据库，这些受访者之间大多都有亲密的关系，包括许多家庭成员和朋友，他们每两至四年间就与心脏研究者见一次面。正是由于这些信息，使得《新英格兰医学杂志》刊登的这项研究的作者们对社会关系对肥胖的影响进行了深入研究。

根据研究人员的分析，如果受访者的朋友肥胖的话，那些受访者自己变胖的可能性会比常人高出57%。如果两人互为挚友，那么这一几率将会高出常人171%。作者之一加州大学圣地亚哥分校的政治科学家詹姆斯·福勒认为并非只是有相似生活习惯的人才会成为朋友。此后詹姆斯·福勒与研究的合著者——哈佛医学院的尼古拉斯·克里斯塔克斯共同对此种可能性进行了研究，结果令他们十分惊讶。一方面，研究表明朋友之间的地理位置差距似乎根本不是问题：相距车程为5小时但经常不见面的朋友在对肥胖的相互影响上和每周都一起吃外卖或打篮球的朋友一样。福勒称友谊引起增重的最好证据就是，人们更加倾向于和心目中的朋友们做一样的事情——但反过来这种关系并不成立。如果你把一个人当作朋友，他变肥胖了的话，那你的肥胖概率会高出常人50%。要是他不把你当朋友，那么即使你胖了，对他的体重也没太大影响。

现在的显著问题是为什么会有此情况？夫妻共处一室，共同进餐和生活，研究者发现当一方变胖时，另一方变胖的几率仅仅高了37%。兄弟姐妹的基因差不多，但他们之间的影响却也小得多，每人变胖的几率只有40%。福勒认为这与社会标准有很大关系，我们看人的时候总是在考虑什么是合适的社会行为。如果你的朋友是肥胖者，这就意味着你认为肥胖是可以接受的。福勒说：“我们选择配偶不会只看他/她的体型、他/她的食量和运动量。”我们也没有必要把自己同兄弟姐妹比较。他还说：“我们不能选择家庭，但我们可以选择朋友。”

福勒和克里斯塔克斯认为这种“传染效应”对于减肥的影响应和增肥一样。福勒说：“我希望这个研究能使人们在考虑健康状况时把家人和朋友的因素也考虑进去。”他说，毕竟，如果你最亲密的人与你一起减肥的时候，这个计划会更加成功。同时，如果你成功减肥，那么你的健康也会帮助其他人达到理想的体重。这种效果不仅对于你的朋友有效，并且对你朋友的朋友，甚至他们（朋友的朋友）的朋友都会有影响。





Unit 57


Past performance is not an indicator of future returns. That, at least, is the advice given to investors. But can the likelihood of a person committing a crime be predicted by looking at his record? The answer, according to a team of clinical forensic psychologists, is that it cannot. Not only is risk prediction unreliable but, when applied to individuals rather than groups, the margins of error are so high as to render any result meaningless.

Making assumptions about individuals from group data is generally only reasonably safe when the variation within the group is small. Despite this, risk assessments are routinely used to help decide who should be locked up, who should undergo therapy and who should go free. Risk prediction is also set to be used to assess the threat posed by people ranging from terrorist suspects to potential delinquents.

Stephen Hart, of Simon Fraser University in British Columbia, Canada, and colleagues decided to determine how accurate the tests of risk assessment are when applied to individuals rather than groups. Typically the tests work by assigning a score to people depending on factors such as their age, the history of their relationships, their criminal past and the type of victims they have chosen. If someone's score places him in a group in which a known proportion has gone on to commit a crime on release from detention, then the risk that person will prove a recidivist is thought to be similar to the risk for the group as a whole.

The paper published by Dr Hart and his colleagues in last month's issue of the British Journal of Psychiatry focused on two popular tests that follow this logic. The first was a 12-item test designed to assess risk for general violence over periods of seven to ten years. The second was a ten-item test designed to assess risk for violence and sexual violence over periods of five to 15 years. The researchers have also assessed other tests used for predicting sexual offences and domestic violence.

They found that variations between members of the groups were very large. In one of the tests, for example, the standard estimate of the chances of members of the group sexually reoffending was put at 36% within 15 years. They calculated that the actual range was between 30% and 43% of the group, with a 95% confidence level. But calculating the average probability for a group is much easier than calculating the same probability for any individual. Thus, using standard methods to move from group inferences to individual ones, they calculated that the chance of any one person reoffending was in the range of 3% to 91%, similarly with a 95% confidence level. Clearly, the seemingly precise initial figure is misleading.

The principle is not peculiar to psychology. It has been recognised by statisticians for decades. They call it the ecological fallacy (although this term captures broader subtleties, too）. Medicine has also been confounded by statistically based procedures. Indeed, the technique is only really useful when the successes and failures are aggregated. A life-insurance company, for instance, could wrongly predict the life span of every person it insured but still get the correct result for the group.

注（1）：本文选自Economist；

注（2）：本文习题命题模仿对象为2004年真题Text 4。

1. What do the clinical forensic psychologists think of risk prediction?

A) Risk prediction fails in the stock market but succeeds in predicting crime probability.

B) Risk prediction is always effective when being applied to groups.

C) Risk prediction is not dependable when it comes to individual behavior.

D) Risk prediction of groups lacks reliability because of high margin error.

2. We can learn from the text that tests of risk assessment are_______.

A) longitudinal

B) very tricky

C) convincing enough

D) unreasonable

3. What premise did Dr Hart follow when conducting his research?

A) Two groups should be designed for the tests, with one test group and the other for comparison.

B) Both risk assessment and risk prediction should be considered in the tests.

C) People selected for the tests should vary greatly from each other so as to guarantee the representativeness of the sample.

D) Given small variation within a group, risk prediction for individuals can be based on group data.

4. According to Dr Hart, using standard methods to predict individuals_______.

A) is as easy as using them for groups

B) yields ineffective statistics

C) can help attain precise results

D) might be influenced by confidence level

5. Which of the following statements is TRUE?

A) Ecological fallacy is originally a psychological phenomenon, which is later adopted in the field of statistics.

B) Statisticians have been dealing with ecological fallacy for a long time and have almost succeeded in figuring out a solution.

C) The statistics from a life insurance company on the longevity of a group of people should be reliable.

D) Risk prediction proves to be of zero practical value according to Dr Hart's study.





篇章剖析


本文主要就风险预测的话题展开论述。第一段首先提出了风险预测站不住脚；第二段指出，只有当一组数据内部差异程度相对较小时，对个人的判断才可能更可靠；第三、四段主要介绍了哈特博士针对以上问题进行的实验；第五段介绍了实验结果，说明了针对个人进行的风险预测有很大的误导性；第六段则进一步对风险预测的负面作用加以延伸，并以一个开放性的建议结束全文。





词汇注释


margin /ˈmɑːdʒɪn/ n. 差数：页边的空白

assessment /əˈsesmənt/ n. 评估，估价

routinely /ruːˈtiːnli/ adv. 例行地；常规地

therapy /ˈθerəpi/ n. 治疗

delinquent /dɪˈlɪŋkwənt/ n. 失职者，违法者

proportion /prəˈpɔːʃən/ n. 比例，均衡

detention /dɪˈtenʃən/ n. 拘留，禁闭

psychiatry /saɪˈkaɪətri/ n. 精神病学，精神病治疗法

domestic /dəˈmestɪk/ adj. 家庭的，国内的

confidence level 置信度

probability /ˌprɒbəˈbɪlɪti/ n. 概率

inference /ˈɪnfərəns/ n. 推论

initial /ɪˈnɪʃəl/ adj. 最初的，初始的

fallacy /ˈfæləsi/ n. 谬误，谬论

confound /kənˈfaʊnd/ vt. 使混淆，挫败

aggregate /ˈæɡrɪɡeɪt/ v. 聚集，合计

insure /ɪnˈʃʊə/ vt. 给…保险