The neuronal signals for smiles usually start in the cortex of our brain. From there they travel to the deeper part, the brainstem -- which, in terms of evolution, also happens to be one of the oldest parts of our brain. From there, a nerve that's large enough to be visible to the naked eye, called the seventh cranial nerve, carries the signal in front of the ear to the more central part of the face, where it reaches the smile muscle.
微笑的神经信号通常开始于我们的大脑皮质。他们从那里传输到更深的部分，脑干——它从进化的角度来讲，也恰好是我们的大脑最古老的部分之一。从那里，一根可以大到肉眼可见的称为第七脑神经的神经，把耳朵前面的信号传到面部更中央的部分，那里它可以到达微笑肌。

The smile muscle is attached from the mouth to the cheekbone. When this nerve fires, the muscle is activated, the corners of our mouth are pulled up, and we look happy. And if it is a true smile, one that signifies real enjoyment by its wearer, then a branch of the facial nerve also activates little muscles around the eyes, leading to wrinkling around the eyes in addition to a mouth smile.
微笑肌附在口腔到颧骨上。当这个神经点燃时，肌肉被激活，我们的嘴角被拉起，然后我们就看起来是快乐的。如果它是一个真正的微笑，表示笑着的人真正的愉悦，那么面部神经的分支也会激活眼睛周围的小肌肉，导致眼睛周围的皱纹，除非它只是一个嘴角的微笑。
Baseball players who had the broadest smiles lived, on average, seven years longer than those who smiled the least.
有着最为灿烂的笑容的棒球球员平均比笑的最少的棒球球员多活七年。
The scientific analysis of the smile really began with the French anatomist Guillaume-Benjamin-Amand Duchenne de Boulogne. In the 1860s, he used electrical currents to make his subjects' "facial muscles contract to speak the language of the emotions and the sentiments." Duchenne believed that one could gain insight into the ways the face expresses emotions by studying the muscles underlying facial movement. He recorded the expressions produced by the electrical stimulation by taking photographs and was the first to use photography to prove a scientific theory. Duchenne showed that in the particular smile he called the "smile of joy," the muscle that is just to the side of the eyes (called orbicularis oculi) is activated. When this muscle contracts, it creates creases, sometimes called crow's feet. He called this the "true smile," the pure smile of enjoyment. Duchenne concluded that the mouth smile obeys the will, but the eye smile does not. He said, "The muscle around the eye ... is only brought into play by a true feeling, an agreeable emotion. Its inertia in smiling unmasks a false friend."
微笑的科学分析真正开始于法国解剖学家纪尧姆 - 本杰明 - 阿芒德·杜兴·德·布洛涅。在19世纪60年代，他用电流使他的实验对象的“面部肌肉收缩，来表达情绪和情感。”杜氏认为，一个人通过学习基本脸部运动，可以洞悉肌肉表达情感的方式。他摄影记录下了电流刺激产生的表情，而且这是第一次用摄影来证明一个科学理论。杜氏表明，在他称之为“欢乐的笑容”的特定微笑中，只是眼睛边的肌肉（称为眼轮匝肌）被激活。当肌肉收缩时，它产生了褶皱，有时也被称为鱼尾纹。他称之为“真正的微笑”，愉悦的纯净笑容。杜氏的结论是，嘴角的笑意服从意愿，但眼睛的笑容没有。他说：“眼部周围的肌肉...只被一种真实的感觉，一种愉快的情感牵动。它在微笑中的惯性揭露了虚假的朋友。”
In the image at right, Duchenne applies electrodes to his cooperative subject in order to stimulate the contraction of the smile muscle (zygomaticus major) that pulls the corners of the mouth up when we smile. His subject is clearly enjoying this. Duchenne's jolt of electricity activates the smile muscle around the mouth, but the gentleman's eyes are also smiling, as seen by the creases formed just to the side of his eyes so the happiness comes from inside. When Duchenne first applied the electricity, only the smile muscle around the mouth was activated; he realized that it didn't look like a true, natural smile, so he told this gentleman a joke to make his eyes smile as well.
在右边的图片上，杜氏对他的合作的实验对象运用电极，以刺激微笑肌（主要是颧肌）的收缩，它在我们微笑时拉起我们的嘴角使其上扬。他的实验对象显然正在享受这个。杜兴的电流激活嘴周围的微笑肌肉，但这位绅士的眼睛也在笑，从只在眼睛周围形成的褶皱中透出了快乐。当杜氏首次运用电流时，只有嘴周围的微笑肌肉被激活;他意识到它看起来并不像一个真正的，自然的微笑，所以他给这位先生讲了个笑话，使他的眼睛也笑了。
Paul Ekman, who led the scientific investigation of facial expressions in the twentieth century, has shown that Duchenne was right. Few of us can fake an eye smile. If you're sitting across from a new business associate and he smiles at you but you're still not sure if you should sign off on a new business venture, look at those little lines around the outside of his eyes. If they wrinkle up like crow's feet, then his smile is a real signifier of pleasure or happiness. The absence of smiling eyes should alert you that your new associate's smile is not necessarily as friendly as it looks.
保罗·埃克曼，在二十世纪领导了面部表情的科学研究，他表明杜氏是正确的。我们很少能假冒眼睛的微笑。如果你坐在一个新的商业伙伴对面，他向你微笑，但你仍然不确定是否应该同意一个新的商业投机，看看他的眼睛外面周围那些细纹。如果它们皱得像鱼尾纹，那么他的微笑就真正意味着快乐或者幸福。没有微笑的眼睛可能提醒你，你新合伙人的微笑并不一定像它看起来那样友好。
A century after Duchenne recorded his remarkable experiments, Dr. Paul Ekman honored the anatomist by terming the smile involving the eyes the "Duchenne smile." Ekman found that the failure to distinguish between different types of smiles showed up in much scientific research over the years and might explain contradictory findings regarding the universal meaning of the smile. Other scientists confirmed their findings and found that the Duchenne smile appears significantly more often when people are freely enjoying themselves than in situations that would require feigned smiles. The eyes do not lie unless, of course, the person has received Botox around the eyes, in which case the skin around the eyes is unable to wrinkle up, no matter how true a smile.
杜兴记录了他非凡的实验的一个世纪后，保罗·艾克曼博士为了表示对解剖学家的敬意，把涉及眼睛的微笑称为“杜兴微笑”。艾克曼发现，区分不同类型微笑的失败出现在历年来很多科学研究中，这可能解释了关于微笑的普遍意义的矛盾研究结果。其他科学家证实了他们的发现，而且发现当人们自由地享受他们自己时，杜兴微笑明显出现得比要求假装微笑的情况下更多。眼睛是不会说谎的，当然，除非这个人眼睛周围已经打了肉毒杆菌，在这种情况下，不论笑容是如何的真挚，眼睛周围的皮肤也不能够皱起来。
Certainly what we see greatly influences when we smile, but it is not necessary. We need no visual feedback to smile. Darwin discovered that those who are born blind will still smile appropriately during a conversation. You can smile when all alone, but smiling is definitely enhanced by socializing; it happens six times more frequently in social settings.
当然，当我们微笑时我们看到极大的影响，但这是不必要的。我们不需要视觉反馈去微笑。达尔文发现，那些天生的盲人在一场交谈中依然会微笑得体。当独自一人时，你可以微笑，但是微笑绝对是通过社交来增强的;它在社会环境中更频繁，是独自一人时候的六倍频率。
Some of the complexities of smiling can be appreciated by examining those who can't do it normally. People who have suffered brain damage may not be able to smile when asked to but will still involuntarily smile at a joke. Conversely, patients suffering from Parkinson's disease, a disease of dopamine-containing neurons in the brain, may be able to turn up the corners of the mouth when asked to smile but after getting a joke may lack the ability to smile as a natural, automatic response. Patients who have had a stroke leading to paralysis of half of their face lack an ability to voluntarily move one side of their face. They show a crooked smile when asked to grin but a normal smile on hearing a joke, indicating intact nerve pathways beyond their conscious control. Clearly, the pathways for smiling are quite elaborate, with both unconscious and conscious connections that receive inputs from different parts of the brain.
有些微笑的复杂性可以通过检查那些不能正常地做到这一点的人来领会。当遭受脑损伤的人被要求微笑时可能无法微笑，但是听了一个笑话还是会不由自主地微笑。相反，患帕金森氏症，一种大脑中含有多巴胺神经元疾病的患者，要求微笑时也许能够把嘴角向上弯，但听了一个笑话后，可能就缺乏作为一种自然，自动的反应的微笑能力。曾中风导致一半的脸麻痹的患者缺乏一种自发运动他们脸的一边的能力。当被要求露齿而笑的时候，他们表现出一个扭曲的笑容，但听到一个笑话时是一个正常的笑容，说明完好无损的神经通路超出了他们的意识控制。显然，微笑的途径是相当复杂的，既有从大脑的不同部位接收输入的无意识的连接，又有有意识的连接。
One wonders whether it is only a coincidence that those of us who socialize the most tend to get less depressed. We have seen how socializing is a great activator of smiling -- perhaps smiling is doing more than we think. Do children suffer less often from depression because they spend more time playing and smiling? It is so easy to forget that your face is always speaking to you: 24/7, your brain is keeping track of how many smiles you created with your face. Your smile scorecard is not something you are consciously aware of, but your unconscious has intimate knowledge of it.
人们不禁要问，我们这些与人交往总是不怎么碰壁是否仅仅是一个巧合。我们已经看到了如何应酬是微笑一个极好的催化剂——也许微笑比我们想象的做得更多。孩子是否因为他们花更多的时间玩耍和微笑,患有阴郁症的几率更小？你的脸总是对你说：每天24小时，你的大脑保持追踪你在你的脸上创造了多少笑容，这是很容易忘记的。你的微笑记分卡不是你是自觉意识到的东西，但你的潜意识非常熟悉它。
I believe that smiling more benefits you directly -- even without its social benefits. You go to the gym to strengthen your muscles. Why not go to the smiling gym to strengthen your positive emotions?
我相信，微笑对你有更直接的益处—— 即使没有它的社会效益。你去健身房增强你的肌肉，为什么不去微笑健身房，以激励你的积极情绪？
One study found that women who had smiled the most in their college yearbook photos had happier lives, happier marriages, and fewer personal setbacks in the following 30 years. Another study finds a correlation between how big a smile you made for a baseball card photo and how long you will live. Those baseball players who had the broadest smiles lived, on average, seven years longer than those who smiled the least.
一项研究发现，在他们的大学纪念册照片里笑的最多的女人有更幸福的生活，幸福的婚姻，并在随后的30年里有更少的个人挫折。另一项研究发现在你为一张棒球卡照片笑的有多大和你会活多久之间的一种相关性。这些有着最为灿烂的笑容的棒球球员平均比笑的最少的棒球球员多活七年。
How could smiling lead to happier marriages and longer lives? The key is probably the reduction of stress that your body and mind feel. Smiling helps generate positive happy emotions within you, and this leads to a decrease in the stress-induced hormones that negatively affect your physical and mental health. Now, of course, there is only a correlation between smiling and a happy life -- it certainly doesn't prove that smiling will make your marriage better or lengthen your life. Perhaps those who smiled most were just innately happier people or smiled more because life was already treating them well in college, predicting more good things to come. Studies such as these can't show what causes what. Waves are correlated with beaches, but do beaches cause waves or waves bring beaches?
微笑是怎样使婚姻更幸福，使生命更长的？关键可能是你的身体和头脑感受压力的减少。微笑让你内在产生积极愉快的情绪，这导致了负面影响你的身体和心理健康的应力感生激素的减少。现在，当然，微笑和幸福的生活之间只有一种关联——这当然不能证明微笑会让你的婚姻更好或者延长你的寿命。也许那些笑的最多的人只是天生更快乐的人，或者笑的多是因为在大学里的生活已经对他们很好，预示着更美好的事情到来。研究像这些的东西不能表明是什么引起了什么。波浪与海滩相关，但是是海滩引起了波浪吗？或者是波浪带来的海滩？
But if one assumes that those who smile more will be happier, what happens to those who smile less? Shouldn't those who developed difficulty smiling as adults suffer more from depression, all other things being equal? Nature has done the experiment if one knows where to look. To probe for cause and effect, doctors studied what happened to patients who, because of facial nerve damage, were unable to move their faces normally. The facial nerve is commonly damaged in adult life by a condition known as Bell's palsy. There are three major parts of the facial nerve, so it is possible to lose the ability to frown but be able to smile, or vice versa. These researchers asked their patients to raise their eyebrows, squint, smile, and pucker their mouths to assess the extent of their facial disability. Their hypothesis was that the inability to smile would increase one's risk of depression.
但是，如果假设那些多笑的人会更快乐，那些笑的人少会发生什么？不应该那些难以微笑的成年人人更容易患有抑郁症，所有其他的事情都是一样的吗？自然已经做过实验，如果有人知道去哪里看。为了探讨原因和影响，医生研究了面部神经受损，无法正常移动他们的脸的患者发生了什么。面部神经在成年生活中一般是被称为贝尔氏麻痹的疾病损伤的。面部神经有三个主要部分，所以失去皱眉头的能力，却能够微笑是可能的，反之亦然。这些研究人员要求他们的病人，以扬起他们的眉毛，眯着眼睛，微笑，抿嘴以评估他们的面部残疾程度。他们的假设是，无法微笑会增加一个人患抑郁症风险。
The results showed that a general impairment in moving one's face was not associated with depression. However, patients who specifically lacked the ability to smile were much more likely to become depressed, and their depression was more severe. There are several possible explanations. First, smiling occurs in social situations and helps facilitate positive emotions and relationships with others. Those individuals who find themselves unable to smile may experience more social isolation, leading to more depressive symptoms from loneliness. This could be a strong negative feedback loop. Second, smiling, by activation of the smile muscle, would initiate a feedback loop to the brain, activating our happy part of the brain, contributing to a more positive mood and more smiling. Those with impaired smiling would have the positive feedback interrupted and more consistent weight on the side of depression. I believe the second explanation is more important, but there is no evidence to help us decide.
结果表明，移动一个人的脸的一般损伤与抑郁症无关。然而，明确地缺乏微笑的能力的患者更可能变得沮丧，他们的抑郁症更严重。有几种可能的解释。首先，面带微笑出现在社交场合，有助于促进正面的情绪和与他人的人际关系。这些发现自己无法微笑的人可能会遇到更多的社交隔离，从孤独导致更多的抑郁症状。这可能是一个强烈的消极反馈循环。第二，微笑，通过激活微笑的肌肉，会启动一个反馈环路到大脑，激活我们大脑快乐的一部分，促成一种更加积极的心情和更多的微笑。那些有身体缺陷微笑的人将中断积极的反馈，对抑郁症的一面是更一致的加重。我认为第二种解释更重要，但没有证据来帮助我们决定。