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Siblings laughing together

As the older sibling are you more successful?

Older siblings are responsible, overachievers, successful. Younger siblings; free-spirited, outgoing, attention-seeking. And ‘only’ children? Well, they’re perfectionists, self-centered and often mature for their age. These are all common birth order stereotypes we’ve heard, however is there any truth to them? Does where you sit amongst your siblings really affect your personality and behavior in adulthood?

According to Deakin University relationship expert Associate Professor Gery Karantzas, the issue of birth order and its implications on identity and personality has been a topic of curiosity for more than 100 years and has in particular been hotly debated for the past 20 years.

Assoc. Prof. Karantzas, Director of the Science of Adult Relationships (SoAR) Laboratory within Deakin’s School of Psychology, says there was evolutionary evidence to suggest that birth order impacted your development.

‘This wasn’t because of parenting or family factors,’ explains Assoc. Prof. Karantzas.

‘Rather the evolutionary processes, whereby each sibling develops slightly different characteristics, as a way of dealing with the possible competition that might exist between siblings, and how they each try to ensure the attention and investment of parents.’

‘Where differences are found, the traditional view is that older siblings are more conscientious, responsible and achievement-oriented. The view of younger – or non-first born – siblings is that they are more rebellious, liberal and agreeable.’

However Assoc. Prof. Karantzas points out there is more recent and alternate evidence that suggests differences are weak at best, and family structure and parenting is a factor that may result in some differences between children. That is, any differences were due to the family environment rather than birth order per se.

‘Two very important studies in 2015 involving thousands of siblings conducted within family analysis revealed no differences in personality traits across siblings due to birth order,’ says Assoc. Prof. Karantzas.

‘So there is little merit to the idea that birth order is a factor in personality differences between siblings.’

‘What we do know is how birth order affects what you learn from your siblings. For example, our older siblings act as important models in which we learn about how to interact in the world.’

‘Very much like our parents and other important people in our family, from them we learn about how it is you can solve problems, how it is that you can regulate your emotions and what are appropriate and inappropriate behaviours to demonstrate in certain situations.’

‘So, if we have really good role models, one of them being our oldest sibling, then we’re in good shape because we’re learning what is appropriate.’

'Where differences are found, the traditional view is that older siblings are more conscientious, responsible and achievement-oriented. The view of younger – or non-first born – siblings is that they are more rebellious, liberal and agreeable.'

Associate Professor Gery Karantzas,
Deakin University

What happens when sibling relationships are non-existent?

Assoc. Prof. Karantzas says there is some suggestion that ‘only’ children are more spoiled and demanding, thus there is a negative stereotype that is at times invoked by wider society.

‘The evidence crushes this inaccurate stereotype. There is little evidence to suggest that “only” children develop differently or experience different developmental outcomes compared to children from families where there are siblings,’ says Assoc. Prof. Karantzas.

The notion that only children are ‘different’ or ‘develop differently’ to children from families with siblings reflects inaccurate assumptions, he says.

‘A recent study on how “only” children fare in romantic relationships in adulthood also finds similar effects. That is, “only” children show no differences in the communication patterns they use in relationships, nor do they show any higher insecurity with one’s partners compared to children with siblings.’

‘The bottom line is that the developmental differences that people may think exist when comparing “only” children to children with siblings do not exist.’

Want to get better at understanding family relationships? Consider studying psychology at Deakin.

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Associate Professor Gery Karantzas
Associate Professor Gery Karantzas

Director of the Science of Adult Relationships (SoAR) Laboratory, School of Psychology, Deakin University

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