谎言是一段与事实相反的消息，指发出信息的一方在知道事实的前提下，刻意隐瞒并提供给另一方的虚假信息，通常带有多种目的。

存心误导别人的有意行为，事先未透露其目的，并且对方也没有明确要求被误导。

谎言就其本质来说是人类对自己的惩罚和戏弄。

说谎也是一种偏差的情绪反应之一。在紧密的人际关系中，激素催产素具有促进说谎的效果。

两种主要形式：

• 隐瞒：省略真实的信息。
• 捏造：把假的信息当成真的说出来。

A lie is a false statement that is presented as if it was true. The practice of communicating lies is called lying, and a person who communicates a lie may be termed a liar. Lies may be employed to serve a variety of instrumental, interpersonal, or psychological functions for the individuals who use them. Generally, the term "lie" carries a negative connotation, and depending on the context a person who communicates a lie may be subject to social, legal, religious, or criminal sanctions. In certain situations, however, lying is permitted, expected, or even encouraged. Because believing and acting on false information can have serious consequences, scientists and others have attempted to develop reliable methods for distinguishing lies from true statements.