10 Surprising Facts Science Has Taught Us About Siblings

1. You Spend More Time With Your Siblings Than Anyone Else

When you’re growing up, sometimes there’s no one you want to hang out with less than your siblings. But of course, it’s much easier for your parents if you just spend some good, old fashioned quality time with your brother or sister – the less kids running around the house while the news is on, the better. Which is why it’s no surprise that a study by Pennsylvania State University revealed by the time children turn 11, they spend around 33% of their spare time with their siblings. And as they grow up – and learn to love those closest to them – they still tend to hang out with each other around 11 hours a week, or 17 hours for those who are from bigger families. Because honestly, who else is going to understand how frustrating your ma’s molly-coddling is more than your sibs?

2. You’re More Likely To Follow Stricter Gender Roles If You Have A Sibling Of The Opposite Sex

If you’ve been brought up with a brother, then it turns out you’re far more likely to follow traditional gender roles. So if you also have a sister, the way you display affection towards her is likely different to the way you would display affection to your brother. In a study entitled Influences on Sibling Relationships, the “warmth-closeness characteristic” is much stronger between siblings of the same gender – likely because of what is deemed appropriate between men and women. Men are considered and expected to be more stoic with their emotions, whereas women are encouraged to be more openly affectionate.

3. Opposite Sex Siblings Make You Better At Dating

While having an older brother can be so, so so annoying when you’re younger, it turns out as you get older, the time spent with your sibling of the opposite sex can make you very good at the dating game. Jeffrey Kluger, author of The Sibling Effect, revealed: “There’s a degree of sensitivity and listening skills in boys who grew up with sisters. Studies show that when you pair people up in five- to 15-minute conversations, as if it were a speed date, the males who grew up with sisters tend to do better than the ones who grew up with brothers or as only children. Similarly, females with brothers tend to do better with boys.” So, you could have your brother to thank next time the banter’s flowing on a Tinder date – rememble to give him a shout-out at the wedding.

4. Having Older Siblings Can Make You Shorter

If you verge a little more on the short side than your brothers and sisters, then your older siblings could be to blame. A New Zealand study of 312 children found that first-born children tended to be taller than the second born, the second born taller than the third born, and… well, you get the idea.

5. Older Siblings Are Smarter Than Younger Siblings

In news that’ll endlessly annoy younger siblings everywhere, research from the University of Edinburgh and Sydney University shows first-borns generally tend to achieve higher IQ test scores from as young as one years old. The study examined data from 5,000 children who were given reading and vocabulary tests once every two years, and by analysing the results in relation to parental behaviour, they discovered the eldest siblings were given more support from their ‘rents with tasks involving thinking, giving them better scores on the tests. Furthermore, previous studies have shown first-borns to be more ambitious and successful, and 16% more likely to pursue higher education than their younger counterparts.

6. But Younger Siblings Are Funnier

So your older siblings might be off getting themselves a degree in something impressive, but can they tell a joke like you can? Of course not, because a recent study revealed that the youngest are the funniest of all the siblings. A YouGov study looking into the personality traits of the oldest and youngest children in British families asked children of varying ages a series of questions on how they perceived themselves. Naturally, the elder siblings felt they were more responsible and organised (and they’re probably right – see above), while the youngest thought of themselves as more chilled and funnier. So yeah, maybe your relatives at the family party might be flocking round your big bro or sis to hear about their impressive job, but can they make your nan laugh so hard sherry comes out of her nose? No, no they can’t.

7. Parents Do Have A Favourite Sibling

Your parents might tell you they love all their offspring equally, but a recent study proved that’s a barefaced lie. But to save you lying awake at night wondering whether it’s you, just know that if you’re not the first-born, it’s probably not. Sorry! A study conducted at the University of California shows out of the 768 parents surveyed, 70% of mothers and 74% of fathers admitted to having a favourite child. The parents didn’t specify which child was their favourite, but results from the study suggest they normally prefer the older child. And it’s not hard to see why really – they are the cleverest, most organised people out there.

8. Sisters Protect Their Siblings From Feeling Low

It seems there’s just something about having a sister that makes siblings just feel that little bit better about themselves. A study conducted by Brigham Young University found that having a sister, no matter where she sits in the chain, will protect you from feelings of depression, loneliness, self-consciousness, guilt and fear, especially as a young teen. The research looked at 395 families with more than one child, at least one of whom was between ten and 14 years old. It also found that brothers were important, too – in fact, having a loving sibling of either gender encouraged good behaviour and kind deeds in children, like being nice to other kids at school or helping out a neighbour – in fact, loving siblings promoted a positive and generous attitude more than loving parents did.

9. You Can’t Replicate Your Sibling Relationship

While saying that your relationship with your sibs is ‘one of a kind’ might just sound like something you tend to tell everyone when you’re a little bit tipsy, it’s actually true. As Kluger writes in The Sibling Effect, “Your parents leave you too soon and your kids and spouse come along late, but your siblings know you when you are in your most inchoate form. Assuming you all reach a ripe old age, they’ll be with you until the very end, and for that reason, there is an intimacy and a familiarity that can’t possibly be available to you in any other relationship in your life. To have siblings and not make the most of that resource is squandering one of the greatest interpersonal resources you’ll ever have.”

10. Having A Sibling Can Make You Slimmer

Remember back in the day, when your mum would force you and your siblings to go and play outside when all you wanted to do was sit in and watch CBBC after school? Well, it turns out that probably did you a lot of good. Unlike those who always had a brother or sister to play with, a study revealed an only child tended to coddled by their parents more and less likely to have to share anything, leading to higher chances of obesity.