by Stephen J. Dubner @Freaknomics
一般認為適當的壓力能夠提高表現，但實際上在有壓力的環境下，人們經常會表現的比平常還要差，有時甚至會犯一些離譜的錯誤，在英語中這叫做 Choking (噎住)。最新一期的 Freaknomics Podcast 探討了什麼是 Choking 以及如何預防 Choking。
Sian Beilock  的研究指出，高認知能力、更聰明的人更容易發生 Choking ，在壓力下表現更差，因為他們平時習慣擁有這些認知資源，在壓力下這些資源經常會降低很多，他們突然之間就不知道怎麼行動了。而壓力的來源也經常是自己，由於自己太過在意，對于一些本應該留給潛意識處理的細節過度專注：
BEILOCK: In my research and in others’, we’ve shown perhaps counterintuitively that individuals who have the most ability to focus, the most working memory, the most fluid intelligence, are actually more prone to perform poorly under stress. And the idea is that if you normally devote lots of cognitive resources to what you’re doing and being in a pressure-filled situation robs you of those resources, you can’t perform as well.
BEILOCK: We know that sometimes people don’t perform up to their potential, precisely when they want to the most. And sometimes that happens because people pay too much attention to the details of what they’re doing, details that should be left on autopilot.
BEILOCK: There’s research showing that when you have friendly faces in front of you, people who are supportive — although that could feel nice, it actually creates pressure-filled situations. You often start thinking of yourself as they might. And so when my mother is in the room, I sometimes think of myself as a young girl. And you also are quite self-conscious.
Anders Ericsson [2,3] 是刻意練習 (deliberate practice) 概念的早期倡導者，他從自己的研究和觀察中發現，在某一個行業或技藝成為精英的人，比一般人更能具體形容自己的領域，對自己的行為更有控制力 (這和 Beilock 的理論有些衝突)，他們更少發生 Choking，甚至可以說成為精英的一部分就是培養能處理高壓力情況的能力：
ERICSSON: …and I think that’s what we’re finding here, is that the really elite people, those who are really able to keep improving, are the ones who actually have a very refined description of the situation and are increasing their control over what they’re doing, as opposed to allowing it just to happen.
ERICSSON: My experience is that choking is quite rare by those individuals that we study, who are consistently excelling. And it seems to be almost part of being an expert is that you deal with the kind of situations that would be experienced as very high-pressure for other people.
經濟學家 Uri Gneezy  想要挑戰傳統勞動市場經濟學的假設，第一個假設是越多的金錢激勵會讓你投入更多的努力，第二是更多的努力會帶來更多的生產力或更好的表現：
GNEEZY: That would have made me very nervous. That would have made me put more effort into this. When we look at incentives in economics, we think about two ways in which it’s going to affect us. The first is that if I’ll pay you more, you’ll put more effort in the task. And the second assumption is that more effort will lead to better performance. That’s not necessarily true. And that’s the part of choking. It might be that I can push you so much to try so hard that it will actually backfire, and you’ll perform worse.
Gneezy 在印度做了一些實驗，發現在更高的金錢激勵下，人們的表現往往會變得更差 (也就是發生 Choking)：
For the three-digit memory game, roughly 40 percent of the participants succeeded under low incentives; under high incentives, the success rate was just 20 percent. For the dart-ball game, the success rate under low incentives was 10 percent; and around 7 percent under high incentives. For the metal packing game? Under low incentives, 25 percent of the participants succeeded; under high incentives, nobody succeeded. Or, put another way, at least 25 percent of them choked.
Gneezy 的後續實驗指出，似乎對於低認知要求的工作，提高金錢激勵的確能獲得更高的生產力，但對於高認知能力要求的工作 (如數字的加減乘除)，更高的激勵一般會帶來更差的表現。
對於要如何避免 Choking， Beilock 提出了兩個方法：
- 模擬真實的高壓力情況進行練習，讓自己對高壓下自己所能調用的心智資源有基本概念，並且事先計劃好怎麼應對。 Ericsson 的建議也大致是這樣。
- (Book) Choke: What the Secrets of the Brain Reveal About Getting It Right When You Have To
- (Book) Peak: Secrets from the New Science of Expertise
- (Freaknomics Episode) How to Become Great at Just About Anything
- (Paper) Choking Under Pressure in Front of a Supportive Audience: Evidence from Professional Biathlon
- (Paper) Large Stakes and Big Mistakes