Secrets of a Higher I.Q.

By Kyoko Kuroda

Are the firstborns really the smartest? The study published in the journal Science and Intelligence in June 2007 with a quarter-million participants says “Yes” to this long-discussed question. Norwegian epidemiologists, Petter Kristensen and Tor Bjerkedal analyzed a database of 241,310 men born from 1967 to 1976 on the relationship between birth order and I.Q. scores using military records. The study found that on average, firstborns had I.Q. of 2.3 points higher than that of their second-born brothers, who appeared to have I.Q. of 1.1 points higher than that of their third-born brothers.

Considering the fact that each family’s situation is different, Kristensen’s team studied brothers raised in the same families. Additionally, several researchers have argued that I.Q. differences originate in prenatal or gestational factors, more specifically an effect of an increased maternal antibody attack by higher birth orders on the fetal brain. To combat this assumption, they studied families whose first-born or first- and second-born children had died before the age of one year. As a result, their scores on average turned out to be the same as those of biological firstborns.

Scores are adjusted for parental education level, mother’s age at birth, sibship size, birth weight and year of conscription. The study was conducted with male participants, but the scientists are quite certain that the results would apply to women as well. In addition, with a sample size of nearly a quarter-million participants, the finding is considered to be compelling scientific evidence.

Although this effect is usually not found among children under the age 12, older siblings seems to find a way to recapture their higher I.Q. during the course of life. Researchers theorize that this precociousness is a sign that the arrival of a younger child disrupts I.Q. level of the older siblings. Younger siblings profit from the readiness, experience and maturation of both the parents and the older siblings, which may be enough to reverse the ascendancy the older sibling had achieved temporarily.

When a younger sibling is born, older siblings take a much expected role as tutors to their younger siblings, according to Robert Zajonc, a social psychologist. This role benefits the older siblings more in developing higher I.Q. than it does to their younger siblings, as they learn to combine their knowledge and skills to teach their younger siblings, enriching their vocabulary and reasoning abilities.

Some studies have indicated that both the older and younger siblings are inclined to depict the firstborn as more disciplined, responsible and successful. The oldest child realizes that his or her best bet to get parental attention is by imitating the parents and/or following their value systems.

On the other hand, younger siblings know that the best tactic for them to steal parental love and attention away from the firstborns is not to compete in the same field. They often differentiate themselves by developing other diverse interests and skills that I.Q. tests do not measure, like social charm, participation in more dangerous sports or interests in studying abroad.

Dr. Sulloway theorizes that children who grew up in the same family tend to become more different from one another than we would expect from genetics alone. Using the evolutionary psychology point of view, which we went over the last month along with Darwin’s survival of the fittest theory, siblings are seeking out for the fittest way to ensure the maximum parental love and attention out of their given circumstances.

New York Times article by Benedict Carey pointed out that the firstborns have won more Nobel Prizes in science than younger siblings, but often by advancing foreknown understandings instead of revolutionizing them. On the contrary, those who are famous for greatly revolutionizing the preexisted understandings are Charles Darwin (the fifth of six siblings), Nicolaus Copernicus (the fourth of four) and Rene Descartes (third of three).
“It’s the difference between every-year or every-decade creativity and every-century creativity,” Dr. Frank Sulloway from Institute of Personality and Social Research said, “between innovation and radical innovation.”

Some may argue that the difference of 2.3 points in I.Q. is modest enough to be overlooked, but let’s not be too quick to judge. According to Sulloway’s statistical analyses, having 2.3 points higher I.Q. than the other would mean having 1.3 points higher probability of winning a spot when applying fort a prestigious university.

In today’s competitive world, where parents put their infants in various classes such as music, movement, baby gym etc, hoping to give them any possible kinds of head start, this I.Q. difference found could be very likely to be taken up as a major difference. Joe Rodgers, a professor and a psychologist from the University of Oklahoma who was not involved in the research claimed that “an awful lot of parents would pay money if their kids could increase I.Q. by two real I.Q. points”.

Back in history, Adler Alfred (1870 -1937), an Austrian psychiatrist and the founder of Individual Psychology pioneered interests in this area of family constellation. Adler theorized birth order as one of the major childhood social influences from which the individual shapes a style of life. Other psychoanalysts used to focus on parent-child, especially mother- child interactions; Adler’s new emphasis on family constellation (the number, age and gender of siblings) was avant-garde. Adler was cautious to mention that birth order does not dictate the personality development; rather it works as a building brick that influences individual’s freely chosen life styles.

Today, it is a popular area of study as Rogers says "birth order has been studied in relation to everything you can think of”.

Current theory on birth order explains that the firstborn child goes through life from experiencing full attention of parents to experiencing the loss of parental attention when the younger sibling arrives. Adler described the oldest sibling as “dethroned” as he experiences the loss of the parental attention. To deal with this consequence, the oldest one may take on a somewhat parental protective role in relationship to the younger siblings. They tend to overvalue authority and have conservative value systems.

The second-born child, seeing the head start of the older sibling, may feel envious, often making him or her rebellious/revolutionary.

Adler described the youngest child tends to be a problem child. The youngest child, as the baby of the family, is at risk of being pampered and spoiled, possibly lacking the motivation to be independent. With too many peacemakers aside, the youngest child may have to compete in many areas, leading to a diffuseness and sense of being overwhelmed. Success may be more attainable when an area of interests not already professed by other siblings can be established.

The only child never competes with siblings for parental attention. Adler suggested that getting undivided attention and never sharing parental love and attention could cause later interpersonal difficulties if he did not get the same kind of love from others. If many years pass between the birth of various children, they will have some characteristics of an only child.
There is not much specific research conducted on the birth order regarding twins, but studies show that twins tend to have one dominate twin who acts as the first born or they may often exchange dominance throughout their lives.

Kristensen’s study unrevealed the underlying mechanism of the long-discussed theory of the firstborns being smarter than their younger siblings. Nurture, not nature was behind this theory and the effect is dependent on the social rank in the family and not the birth order.
Considering this, paying enough attention to each child, spreading the family resources evenly to each child and having your children help others in a way they have to combine and utilize their skills and knowledge may benefit developing higher I.Q. of the children.