The positive and negative effects of the chemical known as the 'love hormone'

被称为“爱情荷尔蒙”的化学物质的积极和消极影响

A Oxytocin is a chemical, a hormone produced in the pituitary gland in the brain. It was through various studies focusing on animals that scientists first became aware of the influence of oxytocin. They discovered that it helps reinforce the bonds between prairie voles, which mate for life, and triggers the motherly behaviour that sheep show towards their newborn lambs. It is also released by women in childbirth, strengthening the attachment between mother and baby. Few chemicals have as positive a reputation as oxytocin, which is sometimes referred to as the 'love hormone'. One sniff of it can, it is claimed, make a person more trusting, empathetic, generous and cooperative It is time, however, to revise this wholly optimistic view. A new wave of studies has shown that its effects vary greatly depending on the person and the circumstances, and it can impact on our social interactions for worse as well as for better.

A 催产素是一种化学物质，一种由脑垂体分泌的荷尔蒙。科学家们最开始注意到催产素的影响是通过在动物身上所做的各种各样的研究。他们发现，它帮助加强草原鼠配偶之间的亲密联系——这种动物一生只有一个配偶，它也能激发母羊对待初生小羊羔的母性行为。女性在生产过程中也会释放出催产素，加强了母亲与婴儿之间的情感联系。很少有化学物质能够像催产素一样拥有正面的名声，它有时候被称作“爱情荷尔蒙”。据称，只要吸进一丁点，就能使一个人变得更加愿意信任别人、更有同情心、更慷慨并且愿意合作。然而，是时候修正些全部都是乐观的观念了。新一波研究显示：它的效果会根据不同的人和场合而有着极大的不同，并且它对我们社会交往行为所产生的影响可好可坏。

B Oxytocin's role in human behaviour first emerged in 2005. In a groundbreaking experiment, Markus Heinrichs and his colleagues at the University of Freiburg, Germany, asked volunteers to do an activity in which they could invest money with an anonymous person who was not guaranteed to be honest. The team found that participants who had sniffed oxytocin via a nasal spray beforehand invested more money than those who received a placebo instead. The study was the start of research into the effects of oxytocin on human interactions. 'For eight years, it was quite a lonesome field,' Heinrichs recalls. 'Now, everyone is interested.' These follow-up studies have shown that after a sniff of the hormone, people become more charitable, better at reading emotions on others' faces and at communicating constructively in arguments. Together, the results fuelled the view that oxytocin universally enhanced the positive aspects of our social nature.

B 催产素在人类行为中所扮演的角色第一次暂露头角是在2005年。在一场突破性的实验中，德国弗莱堡大学的Markus Heinrichs及其团队要求志愿者们进行一项活动：他们可以把钱投资在一个匿名的人身上，而这个人并不能确保会使诚信的。研究组发现，那些事先吸入了催产素的参与者比那些只吸入了安慰剂的人投资了更多的钱。这项研究开启了对催产素如何作用于人类相互之间行为的探索。“在八年的时间里，它一度是一个无人问津的领域”，Heinrichs回忆道。“现在，每个人都深感兴趣”这些后续研究显示，在吸入了这种荷尔蒙之后，人们会变得更加慈悲为怀，更善于读懂他人脸上的情绪，以及在意见不合的争论中进行建设性的沟通对话。综合来看，这些研究结果点燃了这样一种观念：催产素广泛提升了我们社交属性中的那些积极方面。

C Then, after a few years, contrasting findings began to emerge. Simone Shamay-Tsoory at the University of Haifa, Israel, found that when volunteers played a competitive game, those who inhaled the hormone showed more pleasure when they beat other players, and felt more envy when others won. What's more, administering oxytocin also has sharply contrasting outcomes depending on a person's disposition. Jennifer Bartz from Mount Sinai School of Medicine, New York, found that it improves people's ability to read emotions, but only if they are not very socially adept to begin with. Her research also shows that oxytocin in fact reduces cooperation in subjects who are particularly anxious or sensitive to rejection.

C 接下来，几年之后，与此相反的研究发现出现了。以色列海法大学的Simone Shamay-Tsoory 发现，当志愿者玩竞争性游戏时，那些吸入这种荷尔蒙的人在打败对手时表现出了更多乐趣，而在其他人赢了自己的时候感到更多的嫉妒。更有甚者，使用催产素还会根据一个人的性格特征而呈现出相反的效果。纽约西奈山医学院的Jennifer Bartz 发现：它能提高人们解读情绪的能力，但这只是在那些人原本就不擅长社交的情况下才会开始起作用。她的研究还显示，催产素实际上在那些尤为焦虑或对别人的拒绝格外敏感的实验对象上，反而降低了他们的合作性。

D Another discovery is that oxytocin's effects vary depending on who we are interacting with. Studies conducted by Carolyn DeClerck of the University of Antwerp, Belgium, revealed that people who had received a dose of oxytocin actually became less cooperative when dealing with complete strangers. Meanwhile, Carsten De Dreu at the University of Amsterdam in the Netherlands discovered that volunteers given oxytocin showed favouritism: Dutch men became quicker to associate positive words with Dutch names than with foreign ones, for example. According to De Dreu, oxytocin drives people to care for those in their social circles and defend them from outside dangers. So, it appears that oxytocin strengthens biases, rather than promoting general goodwill, as was previously thought.

D 另一项发现是：催产素的效果会随着我们互动的对象而产生变化。比利时安特卫普大学的Caeolyn DeClerck所开展的几项研究表明，吸入了催产素的人在与完全的陌生人打交道时实际上是变得更不合作了。与此同时，荷兰阿姆斯特丹大学的Carsten De Dreu也发现，用了催产素的志愿者们表现出了偏好倾向：荷兰人会更迅速地将荷兰语名字而不是一些外国名字与一些积极词汇联系起来。按照De Dreu的说法，催产素使人们去关爱处在自己社交圈中的人们并保护他们不受外部危险的侵扰。所以，催产素似乎加强了人们的偏见，而不是像先前以为的那样在整体上提升了人们的善念。

E There were signs of these subtleties from the start. Bartz has recently shown that in almost half of the existing research results, oxytocin influenced only certain individuals or in certain circumstances. Where once researchers took no notice of such findings, now a more nuanced understanding of oxytocin's effects is propelling investigations down new lines. To Bartz, the key to understanding what the hormone does lies in pinpointing its core function rather than in cataloguing its seemingly endless effects. There are several hypotheses which are not mutually exclusive. Oxytocin could help to reduce anxiety and fear. Or it could simply motivate people to seek out social connections. She believes that oxytocin acts as a chemical spotlight that shines on social clues - a shift in posture, a flicker of the eyes, a dip in the voice - making people more attuned to their social environment. This would explain why it makes us more likely to look others in the eye and improves our ability to identify emotions. But it could also make things worse for people who are overly sensitive or prone to interpreting social cues in the worst light.

E 从一开始，这些微妙的迹象就存在。Bartz最近指出，在几乎一半的现有研究结果中，催产素都只影响了某些个体或是在某些情况下才起作用。研究者们一度并未对这些发现引起重视，而现在，对催产素效果的更细致的理解正在沿一些新的思路深入推动着调查研究。在Bartz看来，理解这种荷尔蒙到底能够做什么的关键在于锁定它的核心功能，而不是去对它那些看似无穷无尽的效用进行分类。有一些彼此之间并不排斥的假说存在。催产素有助于减少焦虑和畏惧。或者它就是能够驱使人们去找到各种社交纽带。她相信催产素的就像某种化学聚光灯，照耀着种种社交线索——姿势的一个改变，眼睛的轻轻一眨，嗓音的突然降低——使得人们更加适应自己的社会环境。这就能够解释为什么它能够让我们更有可能去注视他人的眼睛并能够提升我们辨别情绪的能力。但是，它也可能会令那些过度敏感或倾向于用最坏的方式解读社交线索的人们面临更糟的局面。

F Perhaps we should not be surprised that the oxytocin story has become more perplexing. The hormone is found in everything from octopuses to sheep, and its evolutionary roots stretch back half a billion years. 'It's a very simple and ancient molecule that has been co-opted for many different functions,' says Sue Carter at the University of Illinois, Chicago, USA. 'It affects primitive parts of the brain like the amygdala, so it's going to have many effects on just about everything.' Bartz agrees. 'Oxytocin probably does some very basic things, but once you add our higher-order thinking and social situations, these basic processes could manifest in different ways depending on individual differences and context.'

F 也许我们并不应该对催产素的故事现在已经变得更加复杂而感到吃惊。这种荷尔蒙在从章鱼到绵羊的每种生物身上都能找到，而它的进化根源能够向前追溯五亿年之久。美国芝加哥伊利诺伊大学的Sue Carter说：“它是一种非常简单而古老的因子，被组合出了许多不同的功能，它作用于大脑最原始的一些部分，例如杏仁体，因此它将会对几乎所有的脑活动都产生许多影响。” Bartz 也赞同这个看法。“催产素大概会产生一些非常基础的功用，但是一旦你再加上我们的高阶思维和社会场合因素，这些基础过程就会根据个体差异和环境而呈现出不同的状况。”