Second born child

Second-born children are the most likely to end up as ‘criminals’


Most first born children would say they’re not surprised by the theory that their younger siblings are more likely to end up on the wrong side of the law. And actually, there’s an ever-growing body of evidence to support this theory.

A study completed earlier this year that followed thousands of sets of brothers in two countries with vastly different environments and cultures, has firmly concluded that second-borns are more likely to test authority than their older siblings. The study found they are more likely to rebel and to find themselves in trouble with authorities.

The study, which followed brothers in both Denmark and Florida, found that despite the differences in ‘environments’ across the two locations, one fact remained true: consistently, second-born boys were 20 to 40 percent more likely to be disciplined in school and come into adverse contact with the role of punishment in the criminal justice system than first-born boys.

It’s not the first time this kind of research has been undertaken, and remarkably, each published study has reached a similar conclusion.

Psychologists have long been interested in the effect of birth order on personality and behaviour, and there are several books that explore the subject including Frank Sulloway’s ‘Born to Rebel which was first published in the 1960s. Sulloway’s most significant finding was that eldest children identify with parents and authority, and generally support the status quo, whilst their younger siblings are more likely to rebel against it.

More recently, the popular parenting book ‘Why First Borns Want to Rule the World and Last Borns Want to Change it’, drew comparable conclusions about the effect of birth order on the way we live our lives.

But the findings became even more interesting when there are more than two-siblings in a household. Studies suggest that ‘middle children’ are around 33% more likely to exhibit delinquent behaviours than first-born, and last-born children are about 20% more likely to exhibit these behaviours than first-born.

Why does birth order have such an impact?

In the most recent study conducted across Denmark and Florida, the authors identified that the higher risk of delinquency was likely due to the fact that second-born children do not receive the one-on-one focus and doting attention from their parents that their older siblings did, and as a result, they may act out in order to get attention. This tendency can become ingrained and flow onto school and general conduct.

The authors also point to the fact that parents tend to take more time off work when they have their first child compared to their second, which can mean that second-borns are not only competing with their older sibling for attention, they are also contending with their parents’ careers and other responsibilities.

The authors further found that anti-social conduct may arise from second-borns looking up to their older sibling as role models, while first-borns look to their parents.

In other words, the oldest child spends more developmental time around adults, which, in turn, leads to more ‘socially acceptable’ conduct. A second-born, on the other hand, will be looking to a toddler or a school-age child as a role model—one who will naturally be less mature, more impulsive and perhaps even egotistical.

What about grades?

There’s also a question of academic ability in the mix. Previous research has found that, as a result of the dedicated time and input from parents, the oldest siblings tend to get better grades than their younger sisters and brothers.

There’s little doubt that parental involvement plays a critical role in the way children develop into adults, and how they then conduct themselves as members of society.

One particular study which looked at factors influencing juvenile crime rates suggested there are three strong influences in children’s lives, particularly as they move into adolescence and young adulthood: these primary influencers are peers, parents and family, and community.

The role of parents

Parenting and family has perhaps the strongest influence, meaning that children with a low-level of parental involvement are more likely to be delinquent, and this, in turn, backs up what we know about the risks faced by children who aren’t raised in stable, nurturing family environments.

So if we are to draw a single conclusion, it would be that parental involvement is critical in instilling life skills and social norms into children – we need to keep teaching our young people positive life skills and give them a strong desire to participate productively within society, rather than outside it.


Sonia Hickey

Sonia Hickey

Sonia Hickey is a freelance writer, magazine journalist and owner of 'Woman with Words'. She has a strong interest in social justice, and is a member of the Sydney Criminal Lawyers® content team.
Ugur Nedim

Ugur Nedim

Ugur Nedim is an Accredited Criminal Law Specialist and Principal at Sydney Criminal Lawyers®, Australia's leading team of criminal and traffic defence lawyers.