Turns out, having a sister makes you happier.

If you have a sister, this might sound all too familiar: growing up, she “borrowed” things she didn’t return, made sure your parents knew about that boy you kissed and could often be a pain in the neck.

But research shows, despite the grief she caused you, you’re better off for having her in your life.

Researchers at De Montfont University and Ulster University in the UK found having a sister makes you happier and more optimistic.

Listen: Lucy Durack talks about her role in Aussie dramedy Sisters. (Post continues…)

They asked 571 young people aged 17 to 25 to fill out a questionnaire quizzing them on their mental health and outlook on life and were able to see a pattern: the participants who grew up with sisters seemed more content.

So what exactly is so great about having a sister?

Well, lead researcher Professor Tony Cassidy explained sisters created an environment where it was okay to talk to each other about problems and lean on each other for support.

“Sisters appear to encourage more open communication and cohesion in families. However, brothers seem to have the alternative effect. Emotional expression is fundamental to good psychological health and having sisters promotes this in families,” he said.

“It could be that boys have a natural tendency not to talk about things. With boys together it is about a conspiracy of silence not to talk. Girls tend to break that down.”

The study also found girls with sisters tended to be more independent and motivated to achieve things.

The findings of the relatively small study were backed up by another from Brigham Young University, in which a quiz of 395 families with at least one 10 to 14-year-old, found having a sister made the pre-teen less likely to feel lonely, unloved, guilty, self-conscious or fearful.

It’s not all bad news for those with brothers, though. The research showed having a sister – or a loving brother – made you a kinder person. A loving sibling of either gender promoted good deeds, such as helping a neighbour or watching out for other kids at school.

So sis, you can thank me later.

Does this research sound about right to you or was your childhood the complete opposite?