Is personality linked to birth order?
Your birth order will not necessarily determine your personality in later life.It has long been thought that the birth order position of an individual impacts on certain personality traits they develop as they grow older.
Generally first born children are thought to be more dominant, middle born children are thought to be more rebellious and last born children are thought of as potentially spoilt.
However, researchers from the University of Leipzig have found that this is no longer the case.
More than 20,000 adults from panel studies in the UK, USA and Germany were studied to compare siblings within families and people with the same birth order across families.
Personality differences were then tested in five key areas: extraversion, emotional stability, agreeableness, conscientiousness and openness to experience; which were measured using self-report scales.
Overall, no effects were found on extraversion, emotional stability, agreeableness or conscientiousness.
However, the fifth trait, openness to experience, was split into two: imagination and intellect. The only difference found in this was that the IQ values of siblings decreased slightly with birth order, which was published in the Proceedings of the National Academy of Sciences this week.
Lead author Julia Rohrer explains that this difference in intellect is incredibly small.
"We can confirm the already well known fact that first borns are a bit more intelligent, but one should keep in mind that it's a really small difference and more importantly, it's not deterministic."
The researchers found that even though there was a slight decline on average intelligence, many of the siblings they compared actually showed the opposite, with younger birth orders presenting higher IQs.
The difference in intellect can be explained in two potential ways: first borns getting the full attention and financial resources of their parents when younger born siblings would have to share, and first borns being able to teach their brothers and sisters.
Rohrer summarises, "The take home message is that we are not somehow doomed by our birth order position, but rather personalities are more complex and cannot simply be explained by whether we are the first borns or last borns."