Firstborn sons have higher IQs [ 2007-06-26 16:36 ]
Firstborn sons have higher IQs than their younger brothers, and their social
status within the family might explain why, researchers said on
Thursday.
A study that used the military draft records of more than
240,000 Norwegian men found that firstborns had an edge of 2.3 IQ points over their next oldest
brothers, who in turn beat brothers born third by an average of 1.1
points.
Men who had been raised as the eldest, whether they were born
first, second, or third, had IQs to match their firstborn peers.
The
same was true for those raised or born second, Petter Kristensen and colleagues
at the University of Oslo reported in the journals Science and
Intelligence.
"This study provides 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," Kristensen's team wrote in Science.
Their studies
confirmed what many scientists had suspected for more than a century - that
firstborns have an edge.
But attempts to prove the effect have been
disputed, in part because the circumstances of each family are
different.
To compensate for this, Kristensen's team studied brothers
raised in the same families.
And some scientists argue that birth order
IQ differences arise in the womb,
while others point to family interactions.
To distill potential
biological effects from social effects, Kristensen's team dug up the young men's
family birth records and found families whose firstborn or first and second-born
children had died before the age of one year.
That was when they
discovered that it was not birth order so much as growing up as the eldest of
the children in a family that made the difference.
(China Daily
06/23/2007 page 1)
Vocabulary:
edge: 优势
womb:子宫
Questions:
1. What seems to explain why older
brothers have higher IQs than their younger male siblings?
2. What had
scientists "suspected for more than a century"?
3. How did the scientists
determine that developmental differences in the womb were likely not the cause
of the IQ gap?
Answers:
1. It is a
matter of how they are socialized. Siblings raised as the oldest in the family
tend to have the highest IQs.
2. That the oldest siblings in a family
have an "edge" - an advantage - in terms of IQ.
3. They studied families
where the oldest siblings had died before the age of 1 and then studied the
younger brothers, who were raised as the oldest.
(英语点津 Linda 编辑)
About the broadcaster:
Matt Doran is an award-winning American newspaper journalist and an
undergraduate student at Albion College. He is currently a polisher for China
Daily Website and is on summer break from Beijing Foreign Studies University,
where he will resume his study of Chinese in the fall.
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