我们一直从生物学角度看待恐惧,而且有人问恐惧倾向是否是遗传的。从人们对老鼠的研究可以发现,哺乳动物确实在某种程度上遗传恐惧倾向。比如,在一项研究中,人们把一群老鼠放到一个没有藏身之处光亮透明的开放式的盒子里。有的老鼠在盒子里四处逛逛,丝毫没有表现出对处于如此暴露环境下的恐惧。但是有的老鼠一动不动,它们靠墙站着,表现出非常恐惧。

当害怕的老鼠或者说像那些站在一处一动不动的焦虑的老鼠,它们之间相互交配繁衍,到12代左右,它们所有的后代都会有恐惧感。甚至当这一代当中新出生的老鼠被鼠妈妈和其它胆大的老鼠混养时,它们成年后仍然有恐惧倾向。

为什么会这样呢?人们认为动物体内特殊基因对动物的焦虑行为有影响。这些基因和大脑当中特殊的神经元接收器有关。顺便说一下,这个似乎也可以应用到人身上。但是当焦虑和恐惧的倾向很可能是遗传特制的时候, 恐惧所呈现的特殊形式与个人所处环境关系更密切。因此,一个特定的恐惧,比如对蛇或者蜘蛛的恐惧不是遗传的,但是对事物整体的恐惧反应倾向是遗传的。

生词摘录:

1. 遗传的 形容词genetic

2. 后代 名词offspring

3. 接受器 名字receptor

 

英文译文：

We've been looking at fear from a biological perspective and someone asked whether the tendency to be fearful is genetic. Some of the studies carried out with mice indicate that mammals do inherit fearfulness to some degree. In one study, for instance, a group of mice were put into a brightly lit open box with no hiding places. Some of the mice wondered around the box and didn't appear to be bothered about being so exposed. But other mice didn't move. They stayed up against one wall which indicated that they were afraid.

When fearful mice, or you might say anxious mice like the ones that stayed in one place, were bred with one another repeatedly, after about twelve or so generations, then all of the offspring showed similar signs of fearfulness. And even when a newborn mouse from this generation was raised by a mother and with other mice that were not fearful, that mouse still tended to be fearful as an adult.

Now why is this? Well, it's thought that specific genes in an animal's body have an influence on anxious behavior. These are genes that are associated with particular nerve-cell receptors in the brain. And the degree of overall fearfulness in the mammal seems to depend largely on the presence or absence of these nerve-cell receptors. This appears to apply to humans as well by the way. But while a tendency towards anxiety and fear may well be an inherited trait, the specific form that the fear takes has more to do with the individual's environment. So a particular fear, like the fear of snakes or the fear of spiders, is not genetic; but the overall tendency to have fearful responses is.