If the thought of a snake slithering around your feet or a spider walking up your arm sends shivers down your spine¹, despite never having come into contact with one in real life, then it could be your genes² that are to blame. Over the last few decades there has been much debate between scientists about whether these phobias are innate³ or are learned during childhood.

如果一想到蛇在你的脚边游动或是蜘蛛在你的胳膊上爬来爬去你就感到脊椎发凉（尽管在现实生活中你从未接触过），那这可能是基因作祟。过去几十年，科学家一直在争论：这些恐惧症究竟是天生的还是在儿童时期通过学习得到的？

But a new study has discovered that it is in fact hereditary⁴, as babies at only six months old (long before they have had a chance to learn about the dangers of spiders and snakes) show signs of stress when they see these creatures.

但一项新研究发现，事实上这是遗传得来的，6个月大的宝宝（早在他们有机会了解蛇和蜘蛛非常危险之前）在看到蛇或者蜘蛛时都会表现出压力。

It is estimated that the UK alone there are over 10 million people living with phobias, and ophidiophobia (fear of snakes) and arachnophobia (fear of spiders) always top the list of the most common concerns, according to a YouGov survey.

据一项YouGov调查表示，据估计，仅英国就有超过1000万人患有恐惧症，恐蛇症和恐蜘蛛症总是位列恐惧症的榜首。

Now a team at the Max Planck Institute for Human Cognitive⁵ and Brain Sciences in Sweden have concluded that it isn’t because we are taught to fear them after birth. In the trial, they showed a group of babies images of spiders and snakes alongside flowers and fish - all the same size and in the same colour.

位于瑞典的马克斯•普朗克人类认知和脑科学研究院的一个团队得出结论：对蛇和蜘蛛的恐惧并不是因为出生后别人教会我们的。在实验中，研究人员给一群宝宝看蜘蛛、蛇以及鲜花与鱼的图片——都是同样的尺寸、同样的颜色。

When the child’s gaze rested upon the snake or spider, rather than the other animals, their pupils enlarged significantly - a classic physiological⁶ signpost that a human is experiencing internal stress.

当宝宝的视线落在蛇或蜘蛛而非其它动物图片上时，他们的瞳孔明显放大——这是人类正在经历内在压力的典型生理指标。

Stefanie Hoehl, lead investigator⁷, said: “In constant light conditions this change in size of the pupils is an important signal for the activation⁸ of the noradrenergic system in the brain, which is responsible for stress reactions. Accordingly, even the youngest babies seem to be stressed by these groups of animals.”

首席研究员斯蒂芬妮•赫厄说道：“在不变的光照条件下，瞳孔大小的变化是大脑去甲肾上腺素被激活的重要信号，去甲肾上腺素是造成压力反应的原因。因此，即使是刚出生的宝宝也会因为这两种动物而感到压力。”

And it would be hard to argue that as a relative newborn, who is immobile, that they had had a chance to learn to be scared of spiders or snakes. Instead they argue that this is an evolutionary⁹ development, and similar to primates¹⁰, mechanisms¹¹ in the human brain have had to develop to react very quickly to these potentially dangerous threats.

而我们都很清楚，作为一个动不了的新生儿，他们并没有机会去学会害怕蜘蛛或蛇。所以有人认为这是一个进化的发展，与灵长类动物相似，人类的大脑机制不得不发展，以快速应对这些潜在的危险。