Like to blame your problems on being the middle child in your family? Too bad. Recent studies have concluded that birth order has little to do with personality traits and behaviour.
The study carried out by the National Academy of Sciences used sample groups from the UK, Germany and the USA in order to see whether the birth order of siblings affected their emotional stability, confidence and overall personality. While previous studies saw a correlation between birth order and confidence, new findings suggest that older children are less likely to be more responsible as studies suggest, and younger children are less likely to be more confident and sociable.
Adler’s study concluded that first-borns were more privileged. However, this was counterbalanced with an increased burden. This was why he concluded that birth order changes the development and growth of our personality, as the first born would be more likely to be neurotic and paranoid, as opposed to the youngest sibling’s more laid out and relaxed outlook on life, a result of an easy and non pressured upbringing.
The study links back to the lives of early humans, suggesting that older siblings who are physically dominant over their younger siblings would develop to be more dominant, and therefore less cooperative.
The 2015 study however used a much larger sample group to test whether birth order affected personality size and the conclusion was that it did not, the results and findings of the study were different on a family to family basis. The study concluded that: “birth order does not seem to be an important consideration for understanding either the development of personality traits or the development of intelligence in the between-family context.”
The study did however show a decline in IQ from first child to last child. In most cases there was an average decrease of 1.5 IQ points for each increase of birth order position. The correlation however is only mild, as only 6 out of 10 older siblings had a higher IQ than their closest sibling. The ‘replicated finding’ of this part of the study showed that it was appropriate to compare with former studies in the field by psychologists such as Adler and Sulloway, both of which argued that personality traits were affected by birth order.