When you see a group of girls or guys and they look hot, but when you see each person individually they are NOT. This is called "cheerleader effect".

当你看见女孩或男孩成群结对在一起时，觉得他们看起来都很辣，但单个来看的话，就没那么迷人了。这就叫作“啦啦队效应”。

To many, cheerleaders are beautiful and sexy. However, their perceived beauty is in part a visual illusion. Any one cheerleader seems far more attractive when she is with her team than when she is alone.

在许多人眼中，啦啦队员们又漂亮又性感。然而，她们的美有一部分是视觉上的幻象。任何一个啦啦队员在队伍中看起来都要比单独看时迷人得多。

New research shows that individual faces appear more attractive when presented in a group than when presented alone. Therefore if you want your profile picture on social media sites to be perceived as attractive, opt for a group shot with friends.

新研究发现，人的脸放在群体中比单独来看显得更迷人。所以如果你想让社交网站上的头像显得漂亮，就选一张和朋友的合照吧。

Example: 

A: I wish I looked like those girls. 

B: Honey that's the cheerleader effect, if you see them individually you will realize they are just plain Janes.

甲：我希望我能长得像那些女孩一样漂亮。

乙：亲爱的，那是啦啦队效应，如果你单个来看她们，你会发现她们长相都很一般。