Boys at the top of the pecking order(长幼次序) either by birth or because their older brothers

Boys at the top of the pecking order(长幼次序) either by birth or because their older brothers died score higher on IQ tests than their younger brothers.
Norwegian researchers now report that it’s a matter of what they call social rank in the family that gives the first born the highest scores or, if the first born had died young, the next oldest.
Kristensen and Bjerkedal studied the IQ test results of 241,310 Norwegian men drafted(征兵) into the armed forces between 1967 and 1976. All were aged 18 or 19 at the time.
The average IQ of first-born men was 103.2, they found second-born men averaged 101.2, but second-born men whose older brother died young scored 102.9. And for third-borns, the average was 100.0. But if both older brothers died young，the third-born score rose to 102.6.
The findings provide “evidence that the relation between birth order and IQ score is dependent on the social rank in the family and not birth order as such.” they concluded.
It’s an issue that has been hotly discussed since at least 1874,when Sir Francis Galton reported that men in noticeable positions tended to be firstborns more often than would have been statistically (统计) expected.
Since then, several studies have reported higher intelligence scores for firstborns, while other analyses have questioned those findings and the methods of those reports.
“These two researchers prove that how study participants(参与者) were raised, not how they were born, is what actually influences their IQs,” said Sulloway, an American professor, who was not part of the research team.
“The elder child pulls ahead,” he said, “perhaps as a result of learning gained through the process of tutoring younger brothers and sisters”.
“The older child benefits by having to organize and express its thoughts to tutor youngsters”, he said, “while the later born children may have no one to tutor.”
【小题1】According to Norwegain researchers’ finding, which of the following is linked to boys’ IQ?A．Birth orderB．Position in the family C．Parents’ social rankD．Educational experience【小题2】What does the sentence “It’s an issue that has been hotly discussed” underlined in Paragraph 6 mean? A．Many people take interest in IQ study. B．IQ study has gone further and further. C．Many people do research on boys’ IQ. D．Opinions are divided on the conclusion.【小题3】According to Kristensen and Bjerkedal’s test results, parents can make youngsters smarter by .A．treating them as the oldest childB．teaching them as the oldest childC．talking to them as much as possibleD．encouraging them to express thoughtsB

(答案→)B 解析：文章讲述的是一项科学研究。挪威的研究人员发现，一个家庭里孩子的IQ的高低与他在兄妹里的排行有关。这项研究出来以后引起了热烈的讨论。【小题1】根据第二段“Norwegian researchers now report that it’s a matter of what they call social rank in the family that gives the first born the highest scores”可知，挪威研究人员认为，男孩在家中的排名先后，与IQ有很大的关系。故选B。【小题2】根据下一段“Since then, several studies have reported higher intelligence scores for firstborns, while other analyses have questioned those findings and the methods of those reports.”可知，从那以后，长幼顺序与IQ的关系引起了激烈的讨论，观点也产生了分歧，故选D。【小题3】根据第五段“The findings provide “evidence that the relation between birth order and IQ score is dependent on the social rank in the family and not birth order as such.”和最后一段“The older child benefits by having to organize and express its thoughts to tutor youngsters”可知，他们认为，男孩的IQ与出生的先后关系，即长幼顺序有关，长子从教弟弟妹妹知识中获益，故选A。

我明天再问问老师，叫他解释下这个问题