Imagine you're given a test with 20 simple math problems. You have 5 minutes to solve as many as possible - and the better you do, the more you'll get paid. When time's up, you're instructed to drop the paper into a shredder. But it's not really going to be shredded.

　　假设你去做一个测试，测试内容是20道简单的数学题。你可以在5分钟之内尽可能多做，做得越多，酬劳越高。时间一到，你就按照指示把答题纸扔进碎纸机。只不过，答题纸并不会真的被粉碎。

　　Instead, the Duke University researchers who devised this experiment hold onto the test. So later, when you report how well you did, they can check to see whether you're lying.

　　这时候，设计这个实验的杜克大学研究人员还在测试你。之后当你汇报自己的成绩时，他们便可以检查你是否在撒谎。

　　And if you're like most people, you've probably fibbed a little bit.

　　实验结果表明大多数人都会撒点小谎。

　　That's because "scheming and dishonesty are part of what makes us human," according to the cover story in the June issue of National Geographic.

　　根据《国家地理》杂志六月刊的一篇封面故事，这是由于“欺骗和不诚实都是人性的一部分”。

　　Contributing writer Yudhijit Bhattacharjee explores psychology, neuroscience and con artistry to explain 'Why We Lie: The Science Behind Our Deceptive Ways'.

　　文章作者余和吉特·巴塔查尔吉探讨了心理学、神经科学和欺骗艺术，来解释“为什么我们说谎：欺骗背后的科学”。

　　Researchers think that pretty much as soon as humans could speak, we were bending the truth.

　　研究人员认为，人类自打会说话以来，就没停止过撒谎。

　　"The ability to manipulate others without using physical force likely conferred an advantage in the competition for resources and mates, akin to the evolution of deceptive strategies in the animal kingdom, such as camouflage," Bhattacharjee writes.

　　巴塔查尔吉写道：“在不动用武力的情况下操纵他人，这项能力可能让你在竞争资源和伴侣时占有优势，有点类似动物世界里不断演变的欺骗战略，好比说伪装。”

　　These days, there seem to be four main reasons we lie.

　　现如今，我们之所以撒谎，似乎有四个主要原因。

　　We do it to promote ourselves or protect ourselves. We do it to affect others, either to be kind or cruel. And then there are the situations that are inexplicable, even to us.

　　我们这么做是为了抬高自己或保护自己。撒谎是为了影响别人，或是出于善意，或是出于恶意。甚至有时连我们自己不清楚自己为什么撒谎。

　　The littlest kids are the least likely to lie, probably because they're still learning how to do it. In an experiment at the University of Toronto, children are asked to guess the identity of a hidden toy.

　　最小的孩子是最不容易撒谎的，或许是因为他们还没学会如何撒谎。在多伦多大学的一项实验中，实验员要求孩子猜藏起来的玩具是什么。

　　The experimenter always leaves the room to take a phone call - which is, of course, a lie - and tells the kid not to peek.

　　实验员总是找借口离开房间去接电话，然后他会告诉孩子不要偷看。

　　"Most children can't resist peeking," Bhattacharjee writes, but how they react after that depends on age.

　　巴塔查尔吉写道：“大多数孩子会忍不住去偷看，不过偷看后的反应取决于他们的年龄。

　　Toddlers usually admit to taking a look, while about 80 percent of eight-year-olds claim they didn't.

　　幼儿们通常会承认自己偷看了，但是大约有80%的八岁小孩会谎称自己没有偷看。

　　They also become gradually savvier about covering up their naughty behaviour. Younger kids who have lied about peeking typically give the correct answer about the toy, while older ones deliberately offer the wrong answer.

　　他们还会渐渐地越来越善于掩饰自己的调皮行为。同样是偷看并撒谎，年龄稍小的孩子通常会给出正确答案，而年龄稍大的孩子则会故意提供错误答案。

　　Studies of adults have shown that brains continue to get more adept at lying over time.

　　针对成年人的研究表明，随着时间推移，大脑会越来越善于撒谎。

　　Given that we all basically grow up to be liars, what's really unbelievable is that we're also so trusting.

　　鉴于我们长大后基本上都会说谎，同时我们又如此轻信他人，这真让人难以置信。

　　But there's an advantage to that, too, Bhattacharjee adds: "Without the implicit trust that we place in human communication, we would be paralysed as individuals and cease to have social relationships."

　　不过这也有个好处，巴塔查尔吉补充说：“如果在人际交往中缺乏彼此信任，我们作为个体将寸步难行，社会关系将不复存在。”