The Mystery of Dogs' Tail Wagging狗摇尾巴的奥秘

Dogs’tails are used for communicating4 with both humans and other dogs.But why did dogs start wagging their tails？ Dogs came from wolves5， but they aredifferent in color and body size， as well as behavior6. Even from a young age， dogswag their tails more than wolves do.

In past studies， dog pups7 would often start to wag their tails for the personwho cared for them by their fourth or fifth week of life. But wolf pups， which werealso raised8 by humans， almost never wagged their tails.

Other studies found that dogs don’t wag them only when they are happy. Theywag their tails more on the right side when they feel happy， and more on the leftwhen they feel sad. And they wag them most when with their owners. Whenanimals are raised by human， some features9 are passed down because humanschoose to keep those features， or because the features help those animals liveamong us.

Studies also found that humans enjoy rhythm10. This might make us like tailwaggingdogs just because we liked the rhythm. It might even explain why dogswag their tails so much when they’re around us.

Future studies will look at types of tail wagging in different situations， alongwith things like heart rate and chemicals in the brain. It is to help us learn howwagging works， and why it began.

狗用尾巴来与人类和其它狗交流。但是狗为什么开始摇尾巴呢？狗由狼进化而来，但它们在颜色和体型以及行为上都有所不同。即使从很小的时候开始，狗摇尾巴的次数就比狼多。

在过去的研究中，小狗在出生后的第四周或第五周经常会对照顾它们的人摇尾巴。但是同样由人类饲养的狼崽几乎从不摇尾巴。

其他研究发现，狗不只在开心的时候摇尾巴。当它们感到高兴时，尾巴更多地向右侧摆动，而在悲伤时，尾巴更多地向左侧摆动。和主人在一起时，它们最喜欢摇尾巴。当动物被人类饲养时，一些特征会被遗传下来，这是因为人类有意保留这些特征，或者因为这些特征有助于那些动物生活在我们中间。

研究还发现，人类喜欢有节奏的事物。这可能会让我们喜欢摇尾巴的狗，只是因为我们喜欢这种节奏。这甚至可以解释为什么狗在我们身边时会不停地摇尾巴。

未来的研究将着眼于在不同情况下摇尾的类型，或伴随着例如心率变化和大脑产生的化学物质，以帮助我们了解摇尾巴是怎么回事以及为什么会出现摇尾这种行为。

（英语原文选自：engoo.id）