Why Smiles Are Contagious

Smile! It makes everyone in the room feel better because they, consciously or unconsciously, are smiling with you. Growing evidence shows that an instinct for facial mimicry allows us to empathize with and even experience other people’s feelings. If we can’t mirror another person’s face, it limits our ability to read and properly react to their expressions. A review of this emotional mirroring appears February 11 in Trends in Cognitive Sciences.

[2] In their paper, Paula Niedenthal and Adrienne Wood, social psychologists at the University of Wisconsin, and colleagues describe how people in social situations simulate others’facial expressions to create emotional responses in themselves. For example, if you’re with a friend who looks sad, you might “try on” that sad face yourself—without realizing you’re doing so. In“trying on” your friend’s expression,it helps you to recognize what they’re feeling by associating it with times in the past when you made that expression.Humans extract this emotional meaning from facial expressions in a matter of only a few hundred milliseconds.

微笑吧！你的笑容令身边的人如沐春风，因为他们会有意或无意地随着你微笑。越来越多的证据表明，人类模仿面部表情的本能让我们能够与他人产生共鸣，甚至体悟他人的感受。如果我们不能模仿另一个人的面部表情，就很难理解对方的表情并做出恰当回应。《认知科学发展新动向》于2月11日刊登了一篇文章，对人类情感模仿本能进行评述。

[2]文章的作者——威斯康星大学的社会心理学家葆拉·尼丹瑟和阿德里安娜·伍德以及他们的同事们，在文章中描述了人在社交场合是如何模仿他人面部表情从而产生自身情感反应的。例如，如果你和一个满面戚容的朋友在一起，可能也不由自主会“换上”那个悲伤的表情。“换上”朋友的表情，并把这个表情与自己过往的类似经历联系起来，可以帮助我们理解朋友的感受。人类能够在短短几百毫秒内从面部表情中提取出这种情感意义。

[3] “You reflect on your emotional feelings and then you generate some sort of recognition judgment, and the most important thing that results is that you take the appropriate action—you approach the person or you avoid the person,” Niedenthal says. “Your own emotional reaction to the face changes your perception of how you see the face, in such a way that provides you more information about what it means.”

[4] A person’s ability to recognize and“share” others’ emotions can be inhibited when they can’t mimic faces. This is a common complaint for people with central or peripheral motor diseases,like facial paralysis from a stroke or Bell’s palsy—or even due to nerve damage from plastic surgery. Niedenthal notes that the same would not be true for people with congenital paralysis,because if you’ve never had the ability to mimic facial expressions, you will have developed compensatory ways of interpreting emotions.

[5] People with social disorders associated with mimicry and/or emotion-recognition impairments,like autism, can experience similar challenges. “There are some symptoms in autism where lack of facial mimicry

[3]尼丹瑟说:“你先是回想自己的情绪感受，然后产生某种认知判断；由此产生的最重要的结果是你采取了适当的行动——靠近或是远离。人类对他人面部表情的情感反应会改变其对面部表情的认知，让人类更加了解面部表情传递的含义。”

[4]当人们不能模仿他人面部表情时，他们识别情绪和“感同身受”的能力就会受到抑制。这在中枢或外周运动疾病的患者身上很常见，如中风或者贝尔氏麻痹症导致的面瘫，甚至由于整形手术造成的神经损伤导致的面瘫。尼丹瑟指出，这对先天性麻痹的患者情况不适用，因为假如你从不具备模仿面部表情的能力，则会找到解读情感的替代方法。

[5]自闭症等与模仿或情绪认知缺陷相关的社交障碍患者可能面临同样的挑战。“自闭症患者的一些症状表现为面部模仿的缺失，其部分原因可能是抑制眼神交流。”尼丹瑟说道。尤其要注意的是，“在社交场合中的眼神交流对于自闭症患者来说可能造成过度刺激，但是在某些情况下，如果鼓励眼神交流，则有利于患者自发地或自动地进行面部表情模仿。”

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may in part be due to suppression of eye contact,” Niedenthal says. In particular,“it may be overstimulating socially to engage in eye contact, but under certain conditions, if you encourage eye contact, the benefit is spontaneous or automatic facial mimicry.”

[6] Niedenthal next wants to explore what mechanism in the brain is functioning to help with facial expression recognition. A better understanding of the mechanism behind sensorimotor simulation, she says, will give us a better idea of how to treat related disorders. ■

[6]下一步，尼丹瑟计划探索大脑中何种机制在帮助人类进行面部表情识别。她说，人类只有更深刻地理解感觉运动模拟机制，才能找到治疗相关疾病的更好办法。 □