首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The term "g"(general intelligence)represents a measure of overall cognitive ability across a variety of tests. It’s not the same
The term "g"(general intelligence)represents a measure of overall cognitive ability across a variety of tests. It’s not the same
admin
2013-09-04
27
问题
The term "g"(general intelligence)represents a measure of overall cognitive ability across a variety of tests. It’s not the same as IQ but it does tend to correlate. Everyone agrees that "g" tends to run in families. But is this down to genetics or to environmental influences?
However, no single gene has yet been conclusively linked to intelligence. Rather it appears to be a case of complex interactions on many levels between many different genes.
Identical twins have exactly the same genes, while non-identical twins share about half their genes. Another feature of twins that makes them an ideal choice for studies is that they tend to be raised in pretty much the same environment. If a particular feature is the same in identical twins, but not in non-identical twins, then chances are it’s mainly genes that are controlling that feature.
So what do the twin studies show? Well, first degree relatives tend to have "g" correlation of about 0.4—0.5.(Perfect correlation is 1; correlation of 0 means that the two things in question are totally unrelated). Identical twins have a correlation of 0.85, while for non-identical twins it’s about 0.6. Which suggests that genes play a very important role, but are not the only factor, since if they were, the correlation between identical twins would be 1.
Identical twins reared apart are almost as similar in "g" scores as those reared together. Adopted children and their adoptive parents have a "g" correlation of zero, while adopted children and their biological parents tend to have the same correlations as any parent-child pair. So although genes don’t seem to be the only thing affecting intelligence, their effects seem to be constant and apparently not overridden by environment.
Does heritability of intelligence alter over a lifetime? Remarkably, it appears so. "g" heritability climbs gradually from 20% in babies to 40% in children, peaking at 60% in adults. Why this should be is still a matter of speculation. It’s been suggested that as our cognitive abilities become more complex, new genes may come into play that were not needed when brain functions were less sophisticated. Or individuals may be drawn towards environments that fit with their genetic makeup, as time goes by and genetic effects that started out small in childhood build up together during adulthood.
Identical twins are chosen as the subjects of the study because______.
选项
A、they have the same genes and live in the same environment
B、they have some genes linked to general intelligence
C、they have the same heritability of intelligence
D、they are alike in everything except for intelligence
答案
A
解析
第三段讲,identical twins(同卵双胞胎)拥有完全相同的基因,而且成长的环境几乎相同,所以是合适的研究对象。
转载请注明原文地址:https://jikaoti.com/ti/P8SYFFFM
0
研究生英语学位课统考(GET)
相关试题推荐
InthefirstyearorsoofWebbusiness,mostoftheactionhasrevolvedaroundeffortstotaptheconsumermarket.Morerecentl
Byalmosteverymeasure,PaulPfingstisanunsentimentalprosecutor.LastweektheSanDiegoCountydistrictattorneysaidhef
Byalmosteverymeasure,PaulPfingstisanunsentimentalprosecutor.LastweektheSanDiegoCountydistrictattorneysaidhef
Asresearcherslearnmoreabouthowchildren’sintelligencedevelops,theyareincreasinglysurprisedbythepowerofparents.T
Thelong-termfortunesofthemoderneconomydependinpartonthestrengthandsustainabilityofthefamily,bothinrelationt
TheAmericanyoungmanspeaksChineseasfluentlyasifhe______aChinese.
Public______fortheusuallylow-budget,high-qualityfilmshasenabledtheindependentfilmindustrytogrowandthrive.
AnOhioStateUniversitystudyhaslinkedbehaviorinyoungchildren【C1】______thetypeofjobtheirmotherhas.Motherswithcom
Explosions.Radiation.Evacuations.Morethan30yearsafterThreeMileIsland,the【C1】______crisisinFukushima,Japan,hasbro
Politically,thenationsoftheworldwillbecomemoretightlyintegratedbecauseofrapidlyimprovingtelecommunicationsandtr
随机试题
治疗热极生风所致的高热神昏、惊厥抽搐,应首选的药物是
慢性不全型肾静脉血栓的临床表现有
对治疗癫痫持续状态有效的药物有
下面是某求助者的WAIS-RC的测验结果:(2011年5月真题)根据测验结果,可以判断该求助者高于常模平均数—个标准差的项目包括()。
钱钟书的《围城》主旨是()。
维特根斯坦是剑桥大学著名哲学家穆尔的学生。有一天,哲学家罗素问穆尔:“你最好的学生是谁?”穆尔毫不犹豫地说:“维特根斯坦。”“为什么?”“因为在所有的学生中,只有他听课时总是露出一副茫然的神色,而且总有问不完的问题。”后来,维特根斯坦的名气超过了罗素。有人
(2011国家95)政策性收益是指由于某些政策、法规的变动而导致的个体收益,这种收益不会导致整个社会财富的增长,只会导致整个社会财富的重新分配。根据上述定义,下列涉及政策性收益的是:
一批产品中一等品、二等品、三等品的比例分别为60%,30%,10%,从中任取一件结果不是三等品,则取到一等品的概率为_______。
在考生目录下有一个工程文件sjt5.vbp,其窗体如图1-83所示。考生目录下有一个in5.dat文件,文件中有5个运动员的姓名、7个裁判的打分和动作的难度系数。每人的数据占一行,顺序是:姓名、7个分数、难度系数。程序运行时,单击“输入”按钮,可把in5
BremoPowerfacilitywillturntheoldcoalstorageareaintoagrassfieldbecause______.
最新回复
(
0
)