You should spend about 20 minutes on Questions 14-26，which are based on Reading Passage 2 below.
How baby talk gives infant brains a boost
The positive and negative effects of the chemical known as the 'love hormone'
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 催产素是一种从脑电波中分泌出来的化学物质。早期的科学家们第一次通过各种动物实验了解了催产素的作用。他们发现催产素能增强草原鼠。 (终身伴侣动物) 这种连接还可以刺激山羊照顾新生羔羊的母亲。女性在怀孕期间也会释放催产激素，以增强母亲和婴儿之间的情感联系。几乎没有什么化学物质能和催产素一样好，催产素有时被称为 爱的荷尔蒙 ”。据说，这种物质可以更可信、更有同情心、更慷慨，并且与淡淡的气味合作。但也许是时候重新审视这种完全乐观的观点了。新一轮研究表明，催产素的作用因人而异，随情况而变化。它对我们的社会互动的影响不仅是好的，而且是坏的。
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.
人们在 2005年就开始意识到催产素对人类行为的影响。在一项开创性的实验中，德国弗赖堡大学的 Markus heinrichs 他和他的同事要求志愿者们做一个名声不详的投资活动。该研究小组发现，以前通过鼻喷吸入催产素的人比那些吸入安慰剂的人投入了更多的钱。这项实验开启了一项研究，以检验催产素对人类相互作用行为的影响。“在过去的八年里，没有人对这个领域感兴趣，” Heinrichs 说: “但是现在大家都很感兴趣。 “一系列的后续实验证明，人在吸入催产素后，变得更善良，更了解别人脸上的情绪, 在辩论中有更多的创造性交流和所有的实验结果，这加强了我们的观点，即总的来说，催产素可以加强社会中的积极因素。
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.
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.
据 dreu, oxytocin 称，人们被敦促关心他们社交圈中的人，并保护他们免受外部危险。因此，与以前的观察相比，催产素加强了这些偏好，而不是促进广泛的善意。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. 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 也许我们不应该对催产素的复杂作用感到太惊讶。这种激素存在于从章鱼到山羊的各种生物中，其进化可以追溯到近 5亿年前: “这是一种非常原始的、古老的分子，可以与不同的物质结合在一起发挥各种功能，” Sue carter 美国芝加哥伊利诺伊大学} “它可以像杏仁一样塑造我们大脑的原始区域，所以它基本上可以影响一切。Bartz 同意。“催产素可能做的事情是非常基本的，但是一旦你把它和我们在一起 (人类) 更先进的思维方式与社会活动联系在一起，这些基本的过程将 “取决于环境，有多重反应”。