It might be difficult to get a good night's sleep the night before a big interview, but we all know it helps.

大型面试前一晚可能很难睡个好觉，但我们都知道睡眠很有帮助。

Now, new research shows that on top of helping¹ people perform better, getting more sleep also makes individuals appear more intelligent to teachers and prospective² employers.

新的研究表明，充足的睡眠除了帮助人们表现更好之外，还会让老师和未来老板觉着这个人更聪明。

A group of psychologists at the University of St Andrews, Scotland looked at 190 faces, belonging to children and adults.

苏格兰圣安德鲁斯大学的一群心理学家研究了190名儿童和成年人的脸。

They measured how open the eyelids³ were and how curved the mouths were using face-processing software.

他们用面部处理软件测量了眼睑的宽度和嘴的弯曲程度。

A panel of more than 200 people were then asked to rate the attractiveness and intelligence of these faces.

研究人员组建了一个200多人的小组，让他们去评价这些面部是否显得有魅力、是否显得聪明。

The results showed that faces with a subtle frown and dropy eyes were perceived as less intelligent.

结果表明，那些有细微皱纹的脸和无神的眼睛让人感觉不聪明。

Photographs were also taken of the same participants after a full night's sleep and after a night of restricted sleep.

研究人员还给这些参与者拍了一组对比照片，以对比睡一宿好觉和睡不好觉的效果。

When the same individuals had less 'eyelid-openness' and a subtle frown it resulted in a significant decrease in their perceived intelligence.

同一个人，眼睑不够宽并带有细微皱纹时，他给人聪明的感觉大大降低。