Part A: Reading Comprehension

Text 4

Although ethics classes are common around the world, scientists are unsure if their lessons can actually change behavior; evidence either way is weak, relying on contrived laboratory tests or sometimes unreliable self-reports. But a new study published in Cognition found that, in at least one real-world situation, a single ethics lesson may have had lasting effects.

The researchers investigated one class session’s impact on eating meat. They chose this particular behavior for three reasons, according to study co-author Eric Schwitzgebel, a philosopher at the University of California, Riverside: students’ attitudes on the topic are variable and unstable, behavior is easily measurable, and ethics literature largely agrees that eating less meat is good because it reduces environmental harm and animal suffering. Half of the students in four large philosophy classes read an article on the ethics of factory-farmed meat, optionally watched an 11-minute video on the topic and joined a 50-minute discussion. The other half focused on charitable giving instead. Then, unknown to the students, the researchers studied their anonymized meal-card purchases for that semester—nearly 14,000 receipts for almost 500 students.

Schwitzgebel predicted the intervention would have no effect; he had previously found that ethics professors do not differ from other professors on a range of behaviors, including voting rates, blood donation and returning library books. But among student subjects who discussed meat ethics, meal purchases containing meat decreased from 52 to 45 percent—and this effect held steady for the study’s duration of several weeks. Purchases from the other group remained at 52 percent.

“That’s actually a pretty large effect for a pretty small intervention,” Schwitzgebel says. Psychologist Nina Strohminger at the University of Pennsylvania, who was not involved in the study, says she wants the effect to be real but cannot rule out some unknown confounding variable. And if real, she notes, it might be reversible by another nudge: “Easy come, easy go.”

Schwitzgebel suspects the greatest impact came from social influence—classmates or teaching assistants leading the discussions may have shared their own vegetarianism, showing it as achievable or more common. Second, the video may have had an emotional impact. Least rousing, he thinks, was rational argument, although his co-authors say reason might play a bigger role. Now the researchers are probing the specific effects of teaching style, teaching assistants’ eating habits and students’ video exposure. Meanwhile, Schwitzgebel—who had predicted no effect—will be eating his words.

36. Scientists generally believe that the effects of ethics classes are

[A]

hard to determine. 

[B]

narrowly interpreted. 

[C]

difficult to ignore. 

[D]

poorly summarized. 

37. Which of the following is a reason for the researchers to study meat eating?

[A]

It is common among students. 

[B]

It is a behavior easy to measure. 

[C]

It is important to students’ health. 

[D]

It is a hot topic in ethics classes. 

38. Eric Schwitzgebel’s previous findings suggest that ethics professors

[A]

are seldom critical of their students. 

[B]

are less sociable than other professors. 

[C]

are not sensitive to political issues. 

[D]

are not necessarily ethically better. 

39. Nina Strohminger thinks that the effect of the intervention is

[A]

permanent. 

[B]

predictable. 

[C]

uncertain. 

[D]

unrepeatable. 

40. Eric Schwitzgebel suspects that the students’ change in behavior

[A]

can bring psychological benefits. 

[B]

can be analyzed statistically. 

[C]

is a result of multiple factors. 

[D]

is a sign of self-development. 

答案解析 (Answers & Explanations)

36. [A] hard to determine.
解析：第一段首句明确指出：“科学家们不确定（are unsure）他们的课程是否能真正改变行为；无论哪种说法证据都很薄弱（weak），因为它们依赖于人为设计的实验室测试或有时不可靠的自我报告”。“unsure”和“weak evidence”说明这种效果是“难以确定的（hard to determine）”，选A。

37. [B] It is a behavior easy to measure.
解析：细节题。第二段第二句详细列举了研究吃肉行为的三个原因：第一，学生对该话题态度可变且不稳定；第二，“行为很容易衡量（behavior is easily measurable）”；第三，伦理学文献基本同意少吃肉是好事。选项B“这是一种容易衡量的行为”是对第二点的原词复现，选B。

38. [D] are not necessarily ethically better.
解析：细节推断题。第三段首句说明 Schwitzgebel 原本预计干预不会产生效果，因为他之前的研究发现：“在包括投票率、献血和归还图书馆书籍等一系列行为上，伦理学教授与其他教授并没有什么不同（ethics professors do not differ from other professors）”。这意味着教伦理的教授在实际的道德行为上并不比别人强，即“他们不一定在道德上更好（are not necessarily ethically better）”，选D。

39. [C] uncertain.
解析：细节推理题。第四段引述了心理学家 Nina Strohminger 的观点：“她希望这种影响是真实的，但不能排除一些未知的干扰变量（cannot rule out some unknown confounding variable）……如果它是真实的，它也可能被另一种助推所逆转：‘来得容易去得快’”。“不能排除未知变量”和“可能被逆转”表明她认为干预的效果是“不确定的（uncertain）”，选C。

40. [C] is a result of multiple factors.
解析：细节推理题。第五段中，Schwitzgebel 怀疑最大的影响来自“社会影响（social influence）”，即同学或助教分享的素食经验；其次是视频可能带来的“情感影响（emotional impact）”；最后是他认为最不激动人心的“理性论证（rational argument）”。他列举了社会、情感、理性等多个方面的原因，说明这种行为的改变是“多种因素共同作用的结果（a result of multiple factors）”，选C。

核心长难句精解 (High-Light)

1. 分号并列结构与现在分词作状语：
"Although ethics classes are common around the world, scientists are unsure if their lessons can actually change behavior; evidence either way is weak, relying on contrived laboratory tests or sometimes unreliable self-reports."
【解析】分号前后连接两个独立的并列句。在分号后的句子中，`relying on...` 是现在分词短语作原因/伴随状语，解释了为什么说证据很薄弱（因为它们依赖于人为设计的实验室测试或不可靠的自评）。

2. 并列宾语从句：
"They chose this particular behavior for three reasons, according to study co-author Eric Schwitzgebel...: students’ attitudes on the topic are variable and unstable, behavior is easily measurable, and ethics literature largely agrees that eating less meat is good..."
【解析】冒号后面引出了对 `three reasons` 的具体解释。这里包含了三个并列的完整句子：1. 学生的态度多变且不稳定；2. 行为易于衡量；3. 伦理文献普遍同意少吃肉是好事。逻辑严密清晰。

3. 双破折号插入语与幽默结尾：
"Meanwhile, Schwitzgebel—who had predicted no effect—will be eating his words."
【解析】双破折号中间 `who had predicted no effect` 构成了非限制性定语从句，作为插入语对 Schwitzgebel 之前的预测进行了补充说明。句末使用了英语中的一个非常生动的双关语 `eat his words`（字面意思是吃掉他的话，引申义为“收回前言/承认自己说错了”），既呼应了文章中“吃肉”的主题，又带有一丝学术自嘲的幽默感。