Have you ever heard that the oldest sibling is the smartest, the middle child may tend to be more rebellious and the youngest one is always searching for more attention? Studies are showing that birth order may not effect one’s intelligence nor their personality. Coming from a family with three children this has been a talked about subject for quite some time, whether it is true or not. While some of the stereotypes hold true for us, others were the opposite. Being the youngest, I can see why we are often thought of as attention grabbers. We always try to keep up with our older siblings and want to establish our place in the family. Middle children are often assumed to be forgotten about and therefore act out more. This was so not the case for my sister, the middle child of the family, she was the angel of the bunch and could normally do no wrong in the eyes of my parents. My brother, the oldest, was the rebellious one but probably the smartest as well. He is now an oral surgeon and doing very well for himself. All of that to say, I was very curious as to if these myths were true.
A study conducted at the University of Illinois asked themselves the same question. They studied 377,000 high school students to find out if birth order had any correlation with intelligence or personality. They sorted through the 377,000 and excluded those who were only children, a twin, triplet, etc. and any who were not a credible source. This left them with 263,712 students to study. They asked their participants several questions about their family life background (i.e. who they live with), demographics and personality. In addition their intelligence in many subjects was tested. As we have learned in class, there are several different outcomes that could appear when looking at a correlational study, if the two do indeed correlate.
- The birth order could be causing the intelligence and personality of the student.
- The intelligence and personality of the student could be causing the birth order.
- A confounding third variable could be responsible for the correlation.
- It was all due to chance.
The reverse causation, number two, does not seem possible. The third variables seems probable just as a hypothesis. The study did take into consideration these factors such as the number of siblings in the family, the families socio-economic background, the age and gender of the student and family structure. They collected two sets of data, one controlling these confounding variables and another without them controlled. The results proved to be rather interesting. There really was not any large correlation between birth order and intelligence/personality. With the variables controlled, the correlation was at .02 which is a positive correlation but not anywhere close to 1. It only jumped up a tiny bit with the variables unconcealed.
A smaller version of a similar study was done at University of Wisconsin. They had a much, much smaller sample size and were looking into more how birth order can influence personality, not so much intelligence. They also studied how parents perceived their children based on their birth order. Most parents did not perceive their children any differently but it was common for them to say that if one child was extroverted, the other would be introverted. Their results were similar to the first study in that personality is not caused by birth order but rather by genetics or by the environment they were raised in.
Now that we have strong evidence that birth order does not cause a certain personality type or intelligence level, we don’t have to place ourselves in certain categories based on where we are in the lineup. If your family does follow the stereotypes, it is most likely due to chance as the correlation is so low. So just because you are the youngest child, does not mean that you can’t achieve a 4.0 G.P.A. and just because you are the middle child does not mean you have to be a rebel. We are free to be ourselves!