Why do we laugh and get amusement from so many different things，from puns (双关语) to pratfalls? Why are some things funny to some people and not to others? How is that while a successful joke can cause pleasure，a sick one can cause serious harm?
Over the centuries，various scholars have attempted to produce a universally agreed-upon theory of humor．Plato and Aristotle introduced the superiority(优越感) theory，the idea that people laugh at the misfortune of others．Their theory seems to explain teasing，but it doesn’t work well for knock-knock jokes．Sigmund Freud argued for his relief theory，the concept that humor is a way for people to release psychological tension and reveal their inner fears and desires．His theory works well for dirty jokes，less well for most puns．
The majority of humor expels today agree with the incongruity theory，the idea that humor arises when there’s a gap between what people expect to happen and what actually happens．Incongruity has a lot going for it — jokes with unexpected funny lines，for example，fit well．But scientists have found that in comedy，unexpectedness is overvalued．
With the goal of developing a new，more satisfactory explanation，I produced “the gentle violation(违背)theory”，the idea that humor arises when something seems wrong or threatening，but is actually OK or safe．A dirty joke，for example，trades on moral or social violations，but it’s only going to get a laugh if the person listening is open enough to consider the subject OK to talk about．Similarly，puns can be seen as linguistic violations that still make grammatical sense．
几世纪以来，不同的学者都试图创建一个公认的幽默理论，柏拉图和亚里士多德提出的优势理论，就是人们嘲笑别人的不幸。他们的理论看似调侃，但对敲门的笑话是不管用的。弗洛伊德认为他的救济理论、概念、幽默，使人们释放心理压力，揭示其内在恐惧和欲望的一种方式。他的理论对一些色情笑话来说是合理的，却不适用于大多数的俏皮话。
如今多数幽默专家同意不协调理论，认为幽默时，那里的人们希望发生的和实际发生的事情之间的间隙不一致。有很多笑话是意想不到的有趣。但是科学家们发现，在喜剧中，不可预测性是被高估的。
为了找到一个令人满意的解释，我研究出“温柔侵犯论”，幽默的时候，那些不对劲或威胁，实际是好的或安全的。例如，色情笑话，在伦理道德上，没什么威胁，只要听者够开放，付之一笑。同样，俏皮话也可以看做是有语法含义的语言行为。
