People believe that birth order influences a person's personality. This is due to the idea that roles in the family usually depend on who came first among the siblings. But as to the findings of a new study, researchers conclude that birth order does not have a lasting impact on a person's life course.
Jocelyn Voo writes that by virtue of being the first child in the family, a firstborn will likely be grounded by more stringent rules. Parents, during these times, are still configuring how to practice parenthood for their child in the best way they know how. This in turn may cause the first child to become more or less a perfectionist - as opposed to middle children who are diplomatic and last-born who are rebellious.
To answer this long-standing question, Professor Stefan Schmukle and Julia Rohrer of Leipzig University and Professor Boris Egloff of Johannes Gutenberg University Mainz (JGU) combined large data sets consisting more than 20,000 subjects from three national panels - Germany, the USA, and Great Britain, as stated in the press release.
With their findings, they confirm that the broad personality traits outside the intellectual domain, including extraversion, emotional stability, agreeableness, conscientiousness, and imagination are not significantly affected by birth order. However, firstborns scored high in vocabulary tests and had less difficulty in abstract reasoning.
The study also supports that objective test performance decline from firstborn down to the last. This association between birth order and intelligence can be clearly seen in large samples. However, there were also a few cases (about 40 percent) that middle children were found to be smarter as compared to their older siblings.
"The real news of our study is that we found no substantial effects of birth order on any of the personality dimensions we examined," says Schmukle. "This does not only contradict prominent psychological theories, but also goes against the intuition of many people."
The study appears in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).
