The Meanest Sibling, According To Research

Are you the mean one in your family?

sister and brother arguing over tv remote kate_sept2004 / Getty Images via Canva

If you're like any of us who have one or more siblings, you know how vastly different you are from each other.

You might share some DNA, but that's about where the similarities end.

It makes you wonder if you were born first, like your older brother, would you act as responsibly as him? 


Or if you were born last, like your sister, you would have been as coddled as she was? 

Research has come out that tells us that our birth order actually does matter, especially when it comes to the relationship between siblings.

RELATED: Who You're Most Compatible With, Based On Your Birth Order

If you grew up with an older brother, you understand how mean they can be — and according to psychologists at the University of Warwick, you're not the only one.

Scientists in the study followed the lives of 6,838 children until they were 12 and studied their family dynamics.

It turns out older brothers are the aggressor in the families, and often the bullies — especially to their younger sisters, and especially in bigger families. 


The study also found that, of the siblings most likely to bully, 69% of them were boys. 

RELATED: Your Parent's Most Favorite Child, Based On Birth Order — Revealed

The study says the reason for such aggression is because of parental approval, as well as the old sibling rivalry of vying to be the favorite of the family.

The oldest sibling had all of the mother's attention before their sibling came along, but when the new child is born, that attention is split between the two, and even more with every child born after. This results in feelings of jealousy and inadequacy in the older sibling, making them take it out on their younger siblings.


However, if your parents had a happy marriage, this likely resulted in a more positive sibling relationship, whereas if there was more tension between your parents, then there was more victimization within the sibling relationship.

The study concluded that "sibling bullying is an evolutionary-driven strategy towards maintaining or achieving social dominance, and older siblings are at particular risk of initiating sibling bullying."

(Turns out your older brother actually could be secretly jealous of all your success and the attention you get?)

RELATED: The Funniest Sibling, According To Research

In sadder news, on top of being a complete bully to you, older brothers have a higher chance of doing more poorly in life than their younger sibs. 


The study found that because your older sibling bullies you so much, they may associate bullying with a positive feeling, thereby leading to a potential lifetime of bad decisions and high-risk behavior, like illicit drug use and even jail time. Yikes.

So, the next time you're at your annual family dinner or Thanksgiving, and you notice your older brother about to give you a noogie, pull out this scientific research and he might think twice before he tries to put you down.

RELATED: Oldest Siblings Most Likely To Cheat, Says New Study


Isabel Steger is a writer and assistant editor at YourTango.