虽然一个完整的智商测试需要一个小时或者更长，并且花费上千元，但这个简单的测试却可以高度预言你的大概智商。

Look at the four cards above. We know for a fact that each card has a letter on one side and a number on the other. Truthful Terry says: ‘Every card that has a D on one side has a 3 on the other.’ What is the fewest number of cards you need to turn over to find out whether Truthful Terry is actually telling the truth? And which ones? The answer is shown at the bottom of the page.

请看上面的四张卡片。我们已知每张卡片都是一面有字母，另一面数字。Truthful Terry说：“每张一面含字母D的卡片，其另一面都是数字3。”你需要翻至少几张牌来确定Truthful Terry究竟有没有说实话？具体又要翻哪张牌呢？答案在文章结尾。

测测看你有多聪明？

If you got it right, congratulations! Either you’ve seen this before or you’re a candidate for Mensa.

如果你回答正确，恭喜！或许你之前看过这个，或许你是世界顶级智商俱乐部门萨的成员。

Seriously, I’ve given this test to hundreds of people up and down the country, and very few get it right (the exception was an audience of Google software engineers, not a single one of whom messed up). The analytical and deductive skills you’ve shown are one of the most important components of intelligence.

事实上，我把这个测试给全国成百上千的人做了，几乎没有人能做对（谷歌的软件工程师们一个也没做对，只有一个他们的观众是个例外）。你所展示的分析和推断能力是智商最重要的组成部分之一。

If you slipped up, don’t worry. The reason is a phenomenon known as confirmation bias. Most people, being charitable sorts, want to turn over the 3, find a D on the back and say: “Well done, Terry!” Actually it doesn’t matter whether the letter on the back of the 3 is D, Z or something else (look back to what he actually said).

如果你答错了，不要担心。这是源于一个名为认知偏见的现象。大多数人作为善良的群体，希望翻开卡片3，发现背后的D，然后说：“做得好，Terry！”事实上，无论在卡片3的背后是字母D，Z或是其他，都无所谓。（回去看一下他究竟说了什么）

Confirmation bias – the tendency to try to confirm pre-existing beliefs – is one reason many people believe complete nonsense (eg homeopathy).

认知偏见——趋向于证实预前存在的信念——是许多人相信完全胡说八道的事情的原因（比如顺势医疗法）。

Ironically the only way to check the truth of Terry’s statement is to try to disconfirm it – ie to try to find evidence that he is wrong (a D on the other side of the 7). 

相反的是，唯一确认Terry的说法是正确的方法就是证明其不成立，也就是说找到他是错的证据（在卡片7的背后发现字母D）。

Answer：Two cards, D and 

答案：至少翻2张卡片，卡片D和卡片7