Let's say you're on a game show. You've already earned $1000 in the first round when you land on the bonus space. Now, you have a choice. You can either take a $500 bonus guaranteed or you can flip a coin. If it's heads, you win $1000 bonus. If it's tails, you get no bonus at all. In the second round, you've earned $2000 when you land on the penalty space. Now you have another choice. You can either take a $500 loss, or try your luck at the coin flip. If it's heads, you lose nothing, but if it's tails, you lose $1000 instead. If you're like most people, you probably chose to take the guaranteed bonus in the first round and flip the coin in the second round. But if you think about it, this makes no sense. The odds and outcomes in both rounds are exactly the same. So why does the second round seem much scarier? The answer lies in a phenomenon known as “loss aversion”. Under rational economic theory, our decisions should follow a simple mathematical equation that weighs the level of risk against the amount at stake. But studies have found that for many people, the negative psychological impact we feel from losing something is about twice as strong as the positive impact of gaining the same thing. Loss aversion is one cognitive bias that arises from heuristics, problem-solving approaches based on previous experience and intuition rather than careful analysis. And these mental shortcuts can lead to irrational decisions, not like falling in love or bungee jumping off a cliff, but logical fallacies that can easily be proven wrong. Situations involving probability are notoriously bad for applying heuristics. For instance, say you were to roll a die with four green faces and two red faces twenty times. You can choose one of the following sequences of rolls, and if it shows up, you'll win $25. Which would you pick? In one study, 65% of the participants who were all college students chose sequence B even though A is shorter and contained within B, in other words, more likely. This is what's called a conjunction fallacy. Here, we expect to see more green rolls, so our brains can trick us into picking the less likely option. Heuristics are also terrible at dealing with numbers in general. In one example, students were split into two groups. The first group was asked whether Mahatma Gandhi died before or after age 9, while the second was asked whether he died before or after age 140. Both numbers were obviously way off, but when the students were then asked to guess the actual age at which he died, the first group's answers averaged to 50 while the second group's averaged to 67. Even though the clearly wrong information in the initial questions should have been irrelevant, it still affected the students' estimates. This is an example of the anchoring effect, and it's often used in marketing and negotiations to raise the prices that people are willing to pay. So, if heuristics lead to all these wrong decisions, why do we even have them? Well, because they can be quite effective. For most of human history, survival depended on making quick decisions with limited information. When there's no time to logically analyze all the possibilities, heuristics can sometimes save our lives. But today's environment requires far more complex decision-making, and these decisions are more biased by unconscious factors than we think, affecting everything from health and education to finance and criminal justice. We can't just shut off our brain's heuristics, but we can learn to be aware of them. When you come to a situation involving numbers, probability, or multiple details, pause for a second and consider that the intuitive answer might not be the right one after all.
假設你參加了一個遊戲節目。 在第一輪,你已經賺到一千美金, 此時你轉到了「獎金」那一格。 現在,你必須要做選擇。 你可以選擇直接拿五百美金獎金, 也可以選擇擲硬幣。 如果擲出正面, 可以贏得一千美金獎金。 如果擲出反面,就完全沒有獎金。 在第二輪, 你已經賺到兩千美金, 此時你轉到了罰金那一格。 現在你又得做選擇了。 你可以選擇直接損失五百美金, 或者選擇試手氣擲硬幣。 如果擲出正面,你沒損失。 但如果擲出反面, 你會損失一千美金。 如果你和大部分人一樣, 第一輪時你可能會選擇 直接拿保證的獎金, 在第二輪時則選擇擲硬幣。 但如果好好想想, 這麼做其實不合理。 這兩輪中的勝算和結果 是完全相同的。 那為什麼第二輪似乎更讓人害怕? 答案在於一種使稱為 「損失厭惡」的現象。 根據理性經濟理論, 我們應該會依據一條簡單的 數學方程式來做決策, 這條方程式會權衡 風險高低和涉及的金額。 但研究發現,對大部分人而言, 我們失去某物時 感受到的負面心理影響 大約是得到同樣東西時 感受到的正面影響的兩倍。 厭惡損失是一種源自 啟發法的認知偏見, 啟發法是根據過去經驗 和直覺來解決問題的方法, 靠的不是細心的分析。 這些心理截徑可能會 導致不理性的決策, 不僅是陷入熱戀或做懸崖高空彈跳, 還有很容易證明有錯的邏輯謬誤。 我們都知道,涉及機率的情況 啟發法通常不太適用, 比如, 如果你要擲一個四面是綠色 兩面是紅色的骰子, 你可以從下列幾個 擲出結果順序中選一個, 擲出來就能得到二十五美金。 你會挑哪一個? 在一項研究中,65% 的 受試者(都是大學生) 選擇 B, 即使 A 比較短,且 B 包含了 A, 換言之,更容易擲出 A。 這就是所謂的合取謬誤。 在這個例子,我們預期 會擲出較多綠色面, 所以我們的大腦誤導我們, 選擇了機率較低的選項。 啟發法也很不適合用來處理數字。 在一個例子中,學生被分為兩組, 第一組被問甘地是在 九歲之前或之後過世的, 第二組被問他是在 一百四十歲之前或之後過世的, 這兩個數字都跟 實際過世年齡差很大, 但接著當學生被要求 猜測他過世的年齡時, 第一組的答案平均為五十歲, 第二組則是六十七歲。 雖然在初始問題中 給的資訊很明顯是錯的, 應該不重要, 但卻仍然影響到學生的估計值。 這是錨定效應的例子, 錨定效應常被用在行銷和談判上, 來提高大家願意支付的價格。 如果啟發法導致了這些錯誤的決策, 那要啟發法幹嘛? 因為啟發法也可以相當有效。 在人類歷史上大部分的時候 生存取決於能否用 有限的資訊快速做出決策。 當沒有時間可以用邏輯思考 來分析所有可能性時, 啟發法有時能救你一命。 但在現今的環境中 要做的決策遠比以前複雜, 且這些決策受到無意識因素 扭曲的程度比我們想的還高, 影響無所不在,從健康 和教育到金融和司法。 我們無法直接關閉大腦的啟發法, 但我們可以學習意識到它的存在。 當你面臨涉及數字、機率, 或多重細節的情況時, 停下來想想,直覺的答案 可能不見得是對的答案。