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At Einstein’s autopsy in 1955, his brain was something of a disappointment: it turned out to be a tad smaller than the average Joe’s. Indeed, later studies have suggested a minimal link between brain size and intelligence. It seems brain quality rather than quantity is key。8 E0 ^% k3 l6 O5 l8 c' j6 u- ~
在1955 年对爱因斯坦尸体的解剖中,他的大脑多少让人有些失望——它比一个成年男子大脑的平均体积还稍微小一点。其实后来的研究也指出,大脑的体积与智力的关系极微,似乎“质”比“量”更为关键。
" x- o2 }: k/ Z2 [# g# a One important factor seems to be how well our neurons can talk to each other. Martijn van den Heuvel, a neuroscientist at Utrecht University Medical Center in the Netherlands, found that smarter brains seem to have more efficient networks between neurons – in other words, it takes fewer steps to relay a message between different regions of the brain. That could explain about a third of the variation in a population’s IQ, he says。* E% u& v& Z! Z+ p8 v; c
一个重要的因素就是我们大脑中的神经元相互的交流度有多好。荷兰乌特勒支大学医学中心的神经科学家马丁·范登·赫维尔发现,较聪明的大脑似乎拥有更加有效的神经元网络,换句话说就是信息在大脑不同区域间传递所花费的步骤更少。他说,人类1/3 的智力差异都是由于这个原因。
+ {7 x/ p5 ^. k3 v Another key factor is the insulating fatty sheath encasing neuron fibers, which affects the speed of electrical signals. Paul Thompson at the University of California, Los Angeles, has found a correlation between IQ and the quality of the sheaths。
* o3 U# J# N1 Z: s8 ~/ I, ]6 s 另一个关键要素是将神经纤维与外界隔离的脂肪鞘,它可以影响电信号的传输速度。加利福尼亚大学洛杉矶分校的保罗·汤普森发现,智力与脂肪鞘质量之间是有关联的。6 ~% j! I l$ f, a, P8 y
We still don’t know exactly how much genes contribute to intelligence, with various studies coming up with estimates rangingfrom 40 to 80 per cent. This wide range of estimates might have arisen because genes contribute more to IQ as we get older, according to a study published last year. By comparing the intelligence of 11,000 pairs of twins, Robert Plomin of King’s College London found that at age 9, genes explain 40 per cent of the variation, but by 17 they account for roughly two-thirds。. e) y) G: @* x
对于基因对智力起的作用占多少,各种研究估计出的比例从40% 到 80% 不等,我们仍然无法确定具体数字。根据去年公布的一项研究,这个宽泛的估计值可能会升高,因为随着年龄的增长,基因对智力的作用会越来越大。通过对1.1 万对双胞胎智力的比较,伦敦国王学院的罗伯特·普洛明发现,9岁的时候,40%的智力差异是由基因影响的,而到了17 岁,比例升到了大概2/3。
' h# j4 [5 f" k How could that be? Perhaps the genes affect how our brain rewires itself as we mature. Alternatively, they may dictate whether someone is likely to seek out stimulating experiences to help their brain grow and develop. “If we are predisposed to have a talent, we may actively seek out an environment to suit it,” says Thompson。7 f' K/ P3 }" U6 F
这种结果是如何产生的呢?也许是因为随着我们长大,基因会影响我们的大脑如何进行神经重塑,要么就是基因会支配一个人是否愿意去寻找有刺激性的体验来帮助他们的大脑生长发育。汤普森说,“如果我们预先决定要创造出一个天才,那我们可能就要积极地去寻找一个环境来配合他的成长”。 |
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