Family dynamics, not biology, behind higher IQ

[Al-khiyal]

NEW YORK, June 21, 2007: The eldest children in families tend to develop slightly higher IQs than their younger siblings, researchers were to report Friday, citing a large study that could effectively settle more than a half-century of scientific debate about the relationship between IQ and birth order.

The difference in IQ between siblings was a result of family dynamics, not of biological factors like changes in gestation linked to repeated pregnancies, the study found.

Researchers have long had evidence that firstborns tend to be more dutiful and cautious than their siblings, early in life and later, but previous studies focusing on IQ differences were not conclusive.

In particular, analyses that were large enough to detect small differences in scores could not control for the vast differences in the way that children in separate families were raised.

The findings, appearing in the Friday issue of the journal Science, are based on detailed records from 241,310 Norwegians, including about 64,000 pairs of brothers, allowing the researchers to carefully compare scores within families, as well as between families.

The study found that eldest children scored about three points higher on IQ tests than their closest sibling. The difference was an average, meaning that it showed up in most families, but not all of them.

Three points on an IQ test, experts said, amounts to a slight edge that could be meaningful for someone teetering between an A or a B, for instance, or even possibly between admission to a leafy liberal arts college or a state university.

They said the results would probably prompt more intensive study into the family dynamics behind such differences, which are yet well understood.

"I consider this study the most important publication to come out in this field in 70 years; it's a dream come true," said Frank Sulloway, a psychologist at the Institute of Personality and Social Research at the University of California at Berkeley. Sulloway, who wrote an editorial accompanying the study, added that "there was some room for doubt about this effect before, but that room has now been eliminated."

Joseph Lee Rodgers, a psychologist at the University of Oklahoma and a longtime skeptic of the birth-order effect, disagreed, saying that the new analysis was not conclusive.

"Past research included hundreds of reported birth-order effects" that were not legitimate, he wrote in an e-mail. "I'm not sure whether the patterns in the Science article are real or not; more description of methodology is required."

In the study, Norwegian epidemiologists analyzed data on birth order, health status and IQ scores of 241,310 18- and 19-year-old men born between 1967 and 1976, using military records. After correcting for factors known to affect scores, including birth weight, family size and parents' education level, the researchers found that eldest children scored an average of 103.2, about 3 points higher than second children and 4 points higher than third-borns.

The scientists then looked at IQ scores in 63,951 pairs of brothers and found the same results. Differences in household environments did not explain elder siblings' higher scores.

Because gender has little effect on IQ scores, the results almost certainly apply to females as well, said Petter Kristensen, an epidemiologist at the University of Oslo and the lead author of the study.

His co-author was Tor Bjerkedal, an epidemiologist at the Norwegian Armed Forces Medical Services.

To test whether the difference could be due to biological factors, the researchers examined the scores of young men who had become the eldest in the household after an older sibling had died. Their scores came out the same, on average, as those of biological firstborns.

"This is quite firm evidence that the biological explanation is not true," Kristensen said in a telephone interview.

Social scientists have proposed several theories to explain how birth order might effect IQ scores. Firstborns have their parents' undivided attention as infants, and even if that attention is later divided evenly with a sibling or more, it means that over time they will have more cumulative adult attention, in theory enriching their vocabulary and reasoning abilities.

But this argument does not explain a consistent finding in children under 12: Among those youngsters, later-born siblings actually tend to outscore the eldest on IQ tests.

Researchers theorize that this precociousness may reflect how new children alter the family's overall intellectual resource pool.

Adding a young child may, in a sense, dumb down the family's overall intellectual environment, as far as an older sibling is concerned; yet the younger sibling benefits from the maturity of both the parents and the older brother or sister. This dynamic may quickly cancel and reverse the older child's head start with Mom and Dad.

Still, the question remains: How do the elders sneak back to the head of the class? One possibility, proposed by the psychologist Robert Zajonc, is that older siblings consolidate and organize their knowledge in their natural roles as tutors to juniors. These lessons, in short, could benefit the teacher more than the student.

Another potential explanation concerns how individual siblings find a niche in the family. Some studies find that both the older and younger siblings tend to describe the firstborn as more disciplined, responsible, a better student. Studies suggest - and parents know from experience - that to distinguish themselves, younger siblings often develop other skills, like social charm, a good curveball, mastery of the electric bass, acting skills.

"Like Darwin's finches, they are eking out alternative ways of deriving the maximum benefit out of the environment, and not directly competing for the same resources as the eldest," Sulloway said. "They are developing diverse interests and expertise that the IQ tests do not measure."

This kind of experimentation might explain evidence that younger siblings often live more adventurous lives than eldest siblings. They are more likely to participate in dangerous sports than eldest children, and more likely to travel to exotic places, studies find. They tend to be less conventional in general than firstborns, and some of the most provocative and influential figures in science spent their childhoods in the shadow of an older brother or sister (or two or three or four).

Charles Darwin, author of the revolutionary "Origin of Species," was the fifth of six children. Nicolaus Copernicus, the Polish astronomer who determined that the sun, not the earth, was the center of the planetary system, grew up the youngest of four. René Descartes, the youngest of three, was a key figure in the Scientific Revolution of the 16th century.

Firstborns have won more Nobel Prizes in science than younger siblings, but often by advancing current understanding rather than overturning it, Sulloway argued.

"It's the difference between every-year or every-decade creativity and every-century creativity," he said, "between creativity and radical innovation."

Family dynamics, not biology, behind higher IQ

[Bent_Bladi]

I knew it...

[Cheba_Mami]

yes, saw it in many families, the eldest makes it good, the rest stays often in a shadow of the older one. I think the older one feels some pressure too from his/her family.

[Bent_Bladi]

It's sad though... the youngest gets compared with the elder siblings, the middle one gets compared with the oldest sibling, and the oldest sibling gets compared with older cousins and neighbor's daughters who are "better"

These parents are never satisfied!!

[Al-khiyal]

June 24, 2007 -- The new evidence that eldest children develop higher I.Q.s than their siblings has intensified the debate over two of the most stubborn questions in social science: What are the family dynamics that enhance intelligence? And can they — and should they — be changed?

The new findings, from a landmark study published Friday, showed that eldest children had a slight but significant edge in — an average of three points over the closest sibling. And it found that the difference was not because of biological factors but the psychological interplay of parents and children.

Predictably, the study set off a swarm of Internet commentary from parents, social scientists and others, speculating about what in families could enrich one child's intellectual environment more than others'.

"Anyone with siblings wonders about this," said Sue Monaco, 51, of Delaware, who has two sons and five siblings. She was one of about 150 readers who posted questions on Friday to a New York Times Web forum about the study.

Researchers acknowledge that few of the family variables affecting intelligence are well understood, and some argue that peer influences are eventually more significant. But studies suggest that two elements are important during childhood: the perceived role a child has in the family; and the apparent benefit a child receives when he or she tutors someone else, like a younger sibling.

Well before entering the high school hothouse of geeks and jocks, children who grow up with siblings get tagged with labels: The screw-up of the family. The airhead, the klutz, the whiner. And then there is the serious one, little Mr. or Ms. Responsible, who most often is the eldest, psychologists have found.

"In our family we had the straight one, the oldest, followed by the one who snuck out," said Elisabeth Ferris, 55, a former teacher who lives near Baltimore. "I was the one who snuck out, who had a lot more fun in high school, and who went to art school."

Studies suggest that other family members tend to consider the eldest the most conscientious of the siblings, more likely to achieve academically. At least for some firstborns, that role may be self-fulfilling.

"I don't know about our I.Q.s but, yes, she was the more studious one," Ferris said of her older sister.

Psychologists say that filling the role of the responsible firstborn, while important to academic achievement, still does not account for eldest children's higher average scores on intelligence tests. Robert Zajonc, a psychologist at Stanford University, has argued that in fact having a younger sibling or two diminishes the overall intellectual environment for eldest children — who otherwise would be benefiting from the rich vocabulary and undivided attention of parents.

This helps explain why, under the age of 12, younger siblings actually outshine older ones on tests.

Something else is at work, Zajonc said, and he has found evidence that tutoring — a natural role for older siblings — benefits the teacher more than it does the student. "Explaining something to a younger sibling solidifies your knowledge and allows you to grow more extensively," he said. "The younger one is asking questions, and challenging meanings and explanations, and that will contribute to the intellectual maturity of the older one." (Only children receive the benefit of more parental attention but miss the opportunity to tutor a younger brother or sister.)

Monaco, who has two sons in their 20s, said her oldest was expected to help his brother from an early age. "He was a teacher to his brother, and he has grown up to be a more intense thinker; he's studying business management," she said. "His brother is more easygoing, independent; he's studying leisure and recreation and has an internship at a golf course." The two are very close friends, she said.

Parents who recognize the different niches that their children fill can enhance the family's intellectual environment by exploiting each child's expertise, researchers say. "Given the evidence we have on this, I would as a parent encourage late-born siblings to take on teaching roles, with other siblings or other children," said Paul Trapnell, a psychologist at the University of Winnipeg.

Trapnell compared this process to the so-called jigsaw approach used in classrooms, in which complex projects are divided up and each child becomes an expert in a particular task and instructs the others.

Younger siblings often have something more to pass on than the tricks of their favorite hobby, or the philosophy behind their social charm. Evidence suggests that younger siblings are more likely than older ones to take risks based on their knowledge and instincts.

It is important to keep in mind, too, that the new study found average difference in I.Q.s; the scores varied widely from family to family. In many families, younger brothers and sisters eventually took the lead in I.Q.s, no matter if they were the screw-up or the whiner.

Moreover, experts have long noted that while even slight differences in score can be important for some, the test measures a narrow set of skills. Excessive attention to it can blind parents to the diverse and equally rich expertise that later-born children usually develop.

The best way to react to the news, some psychologists said, is to relax.

"When parents ask me what to do about this, I always say the same thing: nothing," said Frank Sulloway, a psychologist at the Institute of Personality and Social Research at the University of California, Berkeley, and the author of an editorial in the journal Science that accompanied one of the reports. Another report on the study was published in the journal Intelligence.

"Younger siblings are more likely to take chances," Sulloway added, and to challenge the status quo in creative ways.

Jackie Orsi, 53, of Morrow, Ohio, grew up the youngest of four, five years behind her nearest sibling, and said she discovered in high school that she scored the highest on tests. She remembers the sister closest to her bringing home books from elementary school to read to her.

"The older three held me, cherished me, ragged on me, taught me, and gave me an acute view of life," she wrote in an e-mail message. She added, "I spent my high school years absorbing their books. What a gift. I got my dad's genius genes, and I got a boost from being last-born. Amen."

Study on I.Q. prompts debate on family dynamics

[Bent_Bladi]

i always thought that the oldest was the experiment, and the final product --- the "perfect" result was the youngest

[Cheba_Mami]

and considered the prettiest & relaxed chatty smiling one (if a lady, handsome if a guy), as the youngest one has all the time for beauty& fun. and the elder one has to struggle with the world !