B1 中級 美國腔 1366

 A new drug reduces the risk of heart attacks by 40%. Shark attacks are up by a factor of two. Drinking a liter of soda per day doubles your chance of developing cancer. These are all examples of relative risk, a common way risk is presented in news articles. Risk evaluation is a complicated tangle of statistical thinking and personal preference. One common stumbling block is the difference between relative risks like these and what are called absolute risks. Risk is the likelihood that an event will occur. It can be expressed as either a percentage— for example, that heart attacks occur in 11% of men between the ages of 60 and 79— or as a rate— that one in two million divers along Australia's western coast will suffer a fatal shark bite each year. These numbers express the absolute risk of heart attacks and shark attacks in these groups. Changes in risk can be expressed in relative or absolute terms. For example, a review in 2009 found that mammography screenings reduced the number of breast cancer deaths from five women in one thousand to four. The absolute risk reduction was about .1%. But the relative risk reduction from 5 cases of cancer mortality to four is 20%. Based on reports of this higher number, people overestimated the impact of screening. To see why the difference between the two ways of expressing risk matters, let's consider the hypothetical example of a drug that reduces heart attack risk by 40%. Imagine that out of a group of 1,000 people who didn't take the new drug, 10 would have heart attacks. The absolute risk is 10 out of 1,000, or 1%. If a similar group of 1,000 people did take the drug, the number of heart attacks would be six. In other words, the drug could prevent four out of ten heart attacks— a relative risk reduction of 40%. Meanwhile, the absolute risk only dropped from 1% to 0.6%— but the 40% relative risk decrease sounds a lot more significant. Surely preventing even a handful of heart attacks, or any other negative outcome, is worthwhile— isn't it? Not necessarily. The problem is that choices that reduce some risks can put you in the path of others. Suppose the heart-attack drug caused cancer in one half of 1% of patients. In our group of 1,000 people, four heart attacks would be prevented by taking the drug, but there would be five new cases of cancer. The relative reduction in heart attack risk sounds substantial and the absolute risk of cancer sounds small, but they work out to about the same number of cases. In real life, everyone's individual evaluation of risk will vary depending on their personal circumstances. If you know you have a family history of heart disease you might be more strongly motivated to take a medication that would lower your heart-attack risk, even knowing it provided only a small reduction in absolute risk. Sometimes, we have to decide between exposing ourselves to risks that aren't directly comparable. If, for example, the heart attack drug carried a higher risk of a debilitating, but not life-threatening, side effect like migraines rather than cancer, our evaluation of whether that risk is worth taking might change. And sometimes there isn't necessarily a correct choice: some might say even a minuscule risk of shark attack is worth avoiding, because all you'd miss out on is an ocean swim, while others wouldn't even consider skipping a swim to avoid an objectively tiny risk of shark attack. For all these reasons, risk evaluation is tricky at baseline, and reporting on risk can be misleading, especially when it shares some numbers in absolute terms and others in relative terms. Understanding how these measures work will help you cut through some of the confusion and better evaluate risk.

# 為何人們對錯誤的事情感到恐懼？ (Why do people fear the wrong things? - Gerd Gigerenzer)

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1. ## 1. 單字查詢

在字幕上選取單字即可即時查詢單字喔！

2. ## 2. 單句重複播放

可重複聽取一句單句，加強聽力！

3. ## 3. 使用快速鍵

使用影片快速鍵，讓學習更有效率！

4. ## 4. 關閉語言字幕

進階版練習可關閉字幕純聽英文哦！

5. ## 5. 內嵌播放器

可以將英文字幕學習播放器內嵌到部落格等地方喔

6. ## 6. 展開播放器

可隱藏右方全文及字典欄位，觀看影片更舒適！

1. ## 英文聽力測驗

挑戰字幕英文聽力測驗！

1. 點擊展開筆記本讓你看的更舒服

1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯，不妨使用「俚語字典」，或許會讓你有滿意的答案喔