Level 2 Reading 9B

Ch.18 Reading 9B

第18章 阅读9B

SEEING DOUBLE Many scientists once believed that physical similarities between identical twins are genetic, while their personalities, intelligence, and other differences between them are an effect of their environment. But scientists are now discovering that the boundaries between genetics and environment are not so clear after all. The Jim Twins Identical twins Jim Springer and jim Lewis were adopted as babies and raised by different couples. When the two Jims finally met at age 39, they discovered they had plenty in common. Both were 182 centimeters tall and weighed 82 kilograms. They had the same smile and the same voice. When psychologist Thomas Bouchard Jr. invited the Jim twins to his lab, his colleagues found it very hard to tell them apart. But the similarities didn't stop at the physical. They had both had dogs named Toy. They had both married women named Linda, and then divorced them. They had both been sheriffs, enjoyed making things with wood, suffered severe headaches, and admitted to leaving love notes around the house for their wives. They had so much in common that it seemed unlikely these were just coincidences. Genetics and Intelligence The jim twins were just one of 137 sets of separated twins Bouchard tested. When they compared the twins' IQ scores, Bouchard and his team reached a surprising conclusion. They concluded that intelligence was mostly connected to genetics rather than to training or education. It seemed the differences in family and environment had little effect. However, genes can't control everything, argues geneticist Danielle Reed, who also studies twins. Reed's research shows that, though nothing can truly change our DNA, environmental differences that a child experiences before birth and in their first year can sometimes affect the way the DNA behaves. This can make even identical twins into vastly different people. "What I like to say is that Mother Nature writes some things in pencil and some things in pen," she explains. "Things written in pen you can't change. That's DNA. But things written in pencil you can."

重影 许多科学家曾经认为，同卵双胞胎之间的身体相似性是遗传的， 而他们的个性、智力和其他差异是环境的影响。 但科学家们现在发现，遗传学和环境之间的界限毕竟并不那么清楚。 吉姆双胞胎 同卵双胞胎吉姆·斯普林格和吉姆·刘易斯在婴儿时期被不同的夫妇收养并抚养长大。 当两个吉姆在39岁时终于见面时，他们发现他们有很多共同点。 两人身高182厘米，体重82公斤。 他们有着同样的笑容和同样的声音。 当心理学家小托马斯·布沙尔邀请吉姆双胞胎到他的实验室时，他的同事们发现很难将他们区分开来。 但相似之处并不仅限于身体。 他们都有一只名叫玩具的狗。 他们都娶了一个叫琳达的女人，然后离婚了。 他们都是警长，喜欢用木头做东西， 她患有严重的头痛，并承认在家里给妻子留下了情书。 他们有很多共同点，似乎不太可能只是巧合。 遗传学与智力 这对吉姆双胞胎只是布沙尔测试的137对分离双胞胎中的一对。 当他们比较双胞胎的智商分数时，Bouchard和他的团队得出了一个令人惊讶的结论。 他们得出结论，智力主要与遗传有关，而不是与训练或教育有关。 家庭和环境的差异似乎影响不大。 然而，也研究双胞胎的遗传学家Danielle Reed认为，基因不能控制一切。 里德的研究表明，虽然没有什么能真正改变我们的DNA， 孩子在出生前和第一年所经历的环境差异有时会影响DNA的行为方式。 这甚至可以使同卵双胞胎变成截然不同的人。 她解释说：“我想说的是，大自然母亲用铅笔写一些东西，用钢笔写一些东西。”。 “用钢笔写的东西你无法改变。 那是DNA。但是用铅笔写的东西你可以。"

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