Science and technology.

科技。

Animal cognition

动物的认知

Man's best friend

人类的挚友

Can dogs really show empathy towards humans?

狗真的能感受人类的情绪吗？

DOGS quickly become part of the family. Tales abound¹ of dogs celebrating joy in a household or commiserating² when tragedy strikes. This may not seem surprising after 15,000 years of co-evolution. But what hard evidence is there of dogs' empathy with humans? A new experiment suggests that behind all the waggy tails there really is something deeper going on.

狗很快成了人类家庭中的一员，它们庆祝家庭喜事，怜悯悲剧的发生，这种故事屡见不鲜。在人类与狗共同进化了一万五千年之后，这点或许并不稀奇。但有没有确凿的证据能够证明狗能体会人类的感受呢？最近一项新的实验表明，狗狗背后的确隐藏着更深的含义。

Past experiments have hinted that animals can feel sympathy. Rats and monkeys had been found to forgo⁴ food to avoid delivering electric shocks to relatives. Similarly, apes have recently been documented consoling one another after conflicts. However, all these experiments and observations were demonstrating an animal's sensitivity to distress⁵ in other members of the same species. Deborah Custance and Jennifer Mayer of Goldsmiths College, London, set out to see if dogs could detect the emotional state of humans.

以往的一些实验已经间接地表明动物们也具有同情心。科学家发现，老鼠和猴子会放弃食物，以防自己受到电击而危害同伴。类似的还有大猩猩，它们会在发生争斗后彼此安慰。然而这些实验和观察都只能证明同物种的动物相互之间拥有感受痛楚的能力。伦敦金史密斯大学的黛博拉?科斯坦斯与詹妮弗?梅耶正在着手研究狗，看它们能否察觉人类的情绪状态。

To do this, Dr Custance and Ms Mayer conducted an experiment to study the response of dogs when a nearby human suddenly began to cry. The researchers knew that interpreting responses would be difficult, since dogs tend to whine⁶, nuzzle, lick, lay their heads in laps and fetch toys for people in distress. Although such actions hint³ at a dog wishing to offer comfort, they could also be signs of curiosity, or suggest that a dog is simply distressed⁷ by seeing its master upset.

为了研究这个问题，科斯坦斯博士与梅耶女士进行了一项试验。他们将狗安排在一个人身边，观察狗在此人突然开始哭泣时的反应。他们深知想要解读狗的反应是十分困难的，因为狗在这种条件下经常会发出呜呜声，把鼻子贴在人的大腿上并蹭蹭舔舔，还会在人类悲伤时叼来玩具哄人开心。尽管这样的行为暗示着它们想要给主人提供安慰，但同时也可能仅仅代表了它们的好奇心，又或者它们只是看到主人懊恼感到忧虑罢了。

To work round this, the researchers presented 18 dogs of various breeds with four separate 20-second conditions. They included their owner crying, a stranger crying and both taking it in turns to hum "Mary had a little lamb". All four of these conditions were preceded by two minutes of mundane⁸ conversation between Ms Mayer, who filled the role of the stranger, and the dog's owner.

为了能够正确解读狗的反应，研究者在实验中采用了18条不同品种的狗并将它们分别置于时长均为20秒的四种不同的情境中，分别为主人在一旁哭泣、陌生人在一旁哭泣、主人与陌生人轮流对狗狗哼唱《玛丽有只小羊羔》。在每种情境开始前，梅耶女士都会充当陌生人的角色与狗的主人进行时长两分钟的常规交谈。

Dr Custance and Ms Mayer suspected that if exposure to crying led dogs to feel distress, then regardless of who was crying, the dog would go to their master to seek comfort. They also theorised that if curiosity, rather than empathy, was the driving force, then the humming would cause dogs to engage with people.

科斯坦斯博士与梅耶女士猜想如果狗看到人类哭泣会感到悲伤的话，无论是其主人还是陌生人，狗都会去主人那里寻求安慰。他们还建立了一个理论，如果使狗接近人类的是它们好奇心而非感情上的共鸣，那么哼唱小曲同样会使狗跟人类进行互动。

As they report in Animal Cognition, "person-oriented behaviour" did sometimes take place when either the stranger or the owner hummed, but it was more than twice as likely to occur if someone was crying. This indicated that dogs were differentiating⁹ between odd behaviour and crying. And of the 15 dogs in the experiment that showed person-oriented responses when the stranger cried, all of them directed their attention towards the stranger rather than their owner.

正如他们在《动物的认知》中描述的一样，不管是陌生人还是狗的主人哼唱小曲儿，有时候狗的确会对人类的这些活动作出一定回应，但哭泣的人吸引到狗注意的概率比唱歌的人要高出两倍以上。这表明狗能区分哭泣与其他一些奇怪的行为。在此次实验中有15条狗在看到陌生人哭泣时表现出了同情人类的行为，这些狗都把注意力转向了哭泣的陌生人而非它们的主人。

These discoveries suggest that dogs do have the ability to express empathetic concern. But although the results are clear enough, Dr Custance argues that more work needs to be done to be sure that such behaviour is true empathy. It is possible, she points out, that the dogs were drawing on previous experiences in which they were rewarded for approaching distressed human companions. Dog-owners, however, are unlikely to need any more convincing.

这些发现表明狗的确有表达关心的能力。科斯坦斯博士说，尽管结论已经十分明确，我们仍需要更多做工来确定它们的行为是否真的因为它们能体会人类的感受。她指出，狗可能是出于以往获得的经验即靠近它们的人类同伴能获得奖励进而表现出这种行为。而对于狗能通人性这一点狗主人已经十分清楚了。