There are some different in the brains of shy and outgoing① people when they meet a new face. What’s more， it seems that the difference has its roots in childhood. Individuals’ approaches to unfamiliarity as kids appear to be echoed② by their neural responses to novelty later in life.
The distinction may rest in an almond-shaped region of the brain called the amygdala③， which is involved in emotion and survival. When Carl Schwartz of Massachusetts General Hospital in Charlestown showed pictures of strangers to young adults， he saw more activity in the amygdala of thirteen 21-year-olds with a history of shyness than he did in adults who’ve been oozing④ confidence since kindergarten. “They can see that signature in the brain’s circuitry.
“I guess the biggest surprise for us is that individual differences in response to novel objects are maintained 20 years later，” remarks Schwartz. Past shyness studies have focused on infants， recording details such as their heart rates. This experiment is the first to follow up such children as adults with brain imaging.
Environmental factors， such as overprotective parents or accidents， shape the temperament that people are born with. The hope is that research may help us to understand the complex crosstalk between genes and surroundings at crucial⑤ stages of infant development， and shed light on any connection between childhood anxiety and later psychiatric disorders.
Nonetheless， a correlation between brain activity in adults and childhood temperament⑥ does not prove that being reserved as a child leads to shyness later in life. The study of expert provides a very strong inference， but it does not prove a link.
So does this mean that cowering in the crib destines a person for a quiet life？ Definitely not， says psychologist Simon Killcross of Cardiff University， UK， who studies mechanisms of fear and anxiety. “That a person has difficulty with novelty doesn’t mean they are unable to change—the adult brain is more plastic than the man in the street would imagine.”
① outgoingadj. 直率的； 外出的；出发的
② echovi. 发出回声，产生回响［(+with/to)］；重复他人的话(或行动等)
③ amygdalan. 【植】杏仁之类；桃子之类；【解】扁桃腺
④ oozevi. 渗出；冒出；分泌出； (希望、勇气等)逐渐消失［(+away)］ n. 渗流；分泌；散发
⑤ crucialadj. 决定性的，重要的［(+to/for)］；严酷的，艰难的
⑥ temperamentn. 气质；性情，性格；容易兴奋的性情；喜怒无常；急躁
陌生的面孔点亮害羞的大脑
害羞的和外向的人群面对陌生面孔时，脑部活动具有某种差异。而且，这种差异在年幼时就存在。个体在成年后对新颖事物的脑部神经活动，是他们年幼时对待不熟悉事物时脑部神经活动的一种再现。
这种差别可能来源于脑部一个参与情绪和基本生命活动的杏仁状结构——杏仁体。查尔斯城马萨诸塞州总医院的卡尔·施瓦茨医生，向一组年轻人展示了一系列陌生人的脸部照片。他发现，与从幼年时就很自信的人相比，13个21岁的曾经被确定具有害羞个性的人的杏仁体活动更为强烈。他们可以发现那些脑部回路的特征。
“我认为最让我们吃惊的是个体对新鲜事物反应的差异可以保持20年之久，” 施瓦茨医生表示。以前对害羞的研究集中在婴幼儿身上，记录诸如心率等细节信息。通过脑成像技术跟踪研究儿童直至成人的实验，这还是第一次。
如过分溺爱的父母或意外事故等环境因素，可以改变人天生的气质。对于理解儿童生长发育关键阶段的基因和环境之间的复杂关系、找到儿童焦虑及其以后的精神疾病的关系，这项研究带来了希望。
然而，成人脑部活动和儿童气质的相关性并不能证明童年时害羞的个性会在其以后的生活中一直保持。专家的研究提出了这样一个推论，并不能证明两者的必然联系。
这是否表示在婴儿床上瑟缩成一团的个性害羞的婴儿注定要过平淡的生活？当然不是，英国加的夫大学一位研究害怕和焦虑机制的心理学家西蒙·科尔克劳斯解释说。“一个人面对新事物感到不适并不表示他们就会一直如此——成人脑的可塑性远远超过任何一个人的想象”。