Later borns Not Much at an IQ Disadvantage

A study says that each successive child born into a family has, on average, a slightly lower IQ, by about 0.7 IQ point, than the previous born child… A parallel effect is found on scholastic achievement as well.

Research elicits that firstborns usually enjoy the privilege of a higher IQ score in comparison to their younger siblings. But does that imply that later borns are not bright?

Well the answer is a resounding No! Let us weigh the pros and cons of the discussion.

Lower IQ scores of younger siblings can be explained with "The Resource Dilution Model"

This Resource Dilution Model, proposed by Blake (1981) and elaborated by Downey (2001) offers a simple explanation both for the higher IQ scores of firstborn children and the decreasing IQ scores of successive siblings:

1. "Parental resources are finite." Darwinian Theory of competition exists for resources including money, personal attention and cultural objects such as books. There is no parental bias as such, but additional resources cannot be always created if needed.
2. "Additional siblings reduce the share of parental resources received by any one child." Parents can devote100% of their resources to an only child or a firstborn until other sibling(s) arrive. For example, parents who can afford to send one child to college may not be able to send two children. In this way the younger child might be deprived of some privileges.
3. "Parental resources have an important effect on children's educational success." It is assumed that the relative richness of the environment affects cognitive development

Does It Really Matter?

As per research findings it could be true that firstborns enjoy a higher IQ. But if you are a younger sibling, fret not. I will tell you myriad reasons as to why the above claim is not very important.

First, growing body of research suggests that intelligence is not the most important factor in the achievement of eminence. Several studies have demonstrated that specific personality traits such as conscientiousness and enthusiasm to learn are up to 10 times more important than IQ. Besides, the firstborn advantage is miniscule-about 3 IQ point higher than the second sibling, 2 points higher than the third sibling, and so on. This minute difference does not much impede achievements.

Firstborns are usually more disciplined, responsible and mature, as they have been treated like mini-adults and shouldered household responsibility. The younger siblings are mostly duty shirkers and free-going. Parents know from experience - that in order to stand out, younger siblings often develop soft skills, like social charm, a good curveball, mastery of the electric bass, acting skills etc. Younger siblings often live more adventurous lives than their older brother or sister. They are more likely to participate in adventure sports, and more likely to travel to exotic places, studies report. They tend to be less conventional 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).

"Born to Rebel", one of the best selling novels by Frank Sulloway, University of California psychologist, argues that firstborns keen to remain in the good books of family members, choose to abide norms and not question authority. Consequently it is later borns who bloom into the risk taking, open minded creative individuals who can take the challenges by their horns. Sulloway, himself a second born is the vanguard of this idea who pointed out to Darwin and Copernicus, both later borns, to patronize his case. (Interestingly, Gordon Brown, Tony Blair and David Cameron are all younger children.)

So secondborns and younger siblings, turn that frown into a smile. You have enough reason to cheer!