Humans are not the only animals who have the ability to laugh. Smiling and laughing have been observed in non-human primate species during social play. This type of behavioral response serves as a signal to the group by spreading positive emotions, decreasing stress, and contributing to the cohesiveness of the group.

    Humor-evoked laughter in humans can be divided into these stages. When listening to a joke, the first part of the humor is the punch line, an incongruous ending. Second, your mind begins to problem-solve in order to interpret this incongruity or surprise. Finally, the brain is able to appreciate these steps, which together form humor and evoke a response of laughter.

    The neurotransmitter dopamine (a brain chemical) is responsible for allowing the brain to progress through the stages of humor. Dopamine allows us to feel good when we laugh. Some studies have demonstrated an improvement in health for chronically ill patients when they are exposed to funny stimuli. Thus the old adage “Laughter is the best medicine" probably has a note of truth in it. 

    并不是只有人类能够笑。在灵长目类的社会活动中可以观察到它们会微笑和大笑。这样的行为可以作为一种信号,来对自己的群体传递积极的情绪,降低压力,还有助于增加群体的凝聚力。

    在人类社会中,由幽默引起的笑可以分为三个阶段。当听一个笑话时,幽默的第一部分是一个巧妙的不合常规的结尾。第二,你的头脑开始为了解释这个不合常规或者出乎意料而思考。最后,你的大脑能够欣赏这些过程,这些过程一起构成了幽默并引发了笑。

    神经传递介质多巴胺(脑部一种化学物质)在人脑感受幽默的过程中起了作用。当我们笑的时候,多巴胺让我们感觉心情很好。一些研究已经证实当慢性病病人接触有趣的刺激物时,他们的健康会有逐步的改善。所以这句谚语“笑是最好的药物”也许有事实为证。