Now listen to part of a lecture on this topic in a psychology class.
现在请听心理学课上关于这个话题的部分内容。

For example, I recently read about a case, in which a researcher was given two groups of monkeys,
举个例子，我最近读到了一个案例，在这个案例中，有人给了研究员两群猴子，
and he was asked to train these monkeys to pick up a ball and put it in a box,
让他训练这些猴子把球捡起来并放到箱子里去，
and he was told to record how many hours it took to train each monkey to learn to do this.
研究员被要求记录下来，他训练每只猴子做到这些所花的时间。
Now, before he started the training,
在开始这项训练之前，
the researcher was told that one group of monkeys was highly intelligent and the other group was less intelligent.
研究员被告知其中一群猴子智商很高，而另一群猴子则智商较低。
In truth, there was no difference between them.
但是事实上，这两群猴子并没有什么区别。
All the monkeys were actually very similar in terms of intelligence.
所有猴子的智商水平实际上都十分相近。
But the researcher didn't know that.
可是研究员并不知情。
He thought one group was smarter, so he expected that, that group would be easier to train.
他以为其中一群猴子比较聪明，所以他预想的是，那群聪明的猴子会学得比较快。
So, what happened?
那么，情况如何呢？
Well, the researcher trained the monkeys to perform the action, and it turned out that,
研究员教会了这些猴子做那些事情，而且结果显示，
on average, it took him two hours less time to train the supposedly smart monkeys than the supposedly less intelligent monkeys.
他教会这群按理来说聪明些的猴子所花的时间，平均比教会那群所谓智商较低的猴子所花的时间要少两个小时。
Why? Well, it turns out that with the supposedly smart monkeys the researcher smiled at them a lot,
为什么呢？原来研究员对这群他以为要聪明些的猴子笑得多些，
gave them a lot of encouragement, talked to them a lot, worked hard to communicate with them.
给了它们很多鼓励，经常对它们讲话，并且很努力地跟它们进行沟通。
But with the monkeys he thought were less intelligent,
但是对那群他以为智商较低的猴子，
he wasn't this enthusiastic, he didn't try this hard, wasn't quite optimistic.
就没有那么热情了，训练的时候也没有很上心，对它们也没有多么积极。