It evolved out of the sounds primates make while roughhousing.

它是从灵长类动物打架斗殴时发出的声音演变而来的。

" It seems like little and big boys always want to roughhouse and play hard."

“似乎小男孩和大男孩总是想打闹，玩得很开心。”

They're made to be roughhoused and all those things.

他们生来就是为了粗暴对待等等。

(Laughter) Our play just didn't involve that kind of roughhousing that my son and his friends were into.

（笑声）我们的游戏并不像我儿子和他的朋友们那样打闹。