Sibling rivalry: why the hellish family dynamic long outlives childhood

Name: Sibling rivalry.

Age: Ever heard of Cain and Abel?

Appearance: A weeping, unhealed wound.

Why can I suddenly hear the Succession theme tune? Because it’s a banger. And also because Succession is, at heart, a show about some bruised children squabbling for the attention of their daddy.

Good thing it’s only a TV show, right? Oh, you poor sweet fool. Sibling rivalry is a real thing, and new research proves that it doesn’t just end at childhood.

No? No. According to a study commissioned by Now TV, in a poll of 2,000 adults, a quarter of people still find themselves fighting with their brothers and sisters long into adulthood.

About what? The short answer is everything. The longer answer is lingering competitiveness over their careers, their homes, their cars, their holidays, their education, their cooking skills and, naturally, who their parents like best.

Really? Even into adulthood? Of course. Family dynamics are often hard-coded into a person during childhood, and they’re hard to shift. Have you ever visited a romantic partner’s family for Christmas? It’s like they turn into a completely different person.

But only a quarter of adult siblings fight. This wasn’t included in the research data, but I imagine that the other three-quarters spend their lives in a state of chilly quasi-estrangement, only communicating in brief texts three or four times a year.

God, this is bleak. Right? Basically, the fastest way a parent can screw up their child is by having another child.

Are there no upsides at all? Some respondents claimed that their competitive sibling relationship only helped to spur them on to achieve better things in life. And also, a sibling can be a lovely thing to have. Remember, your relationship with a sibling is likely to be the longest relationship you’ll ever have.

So there’s bound to be conflict. Absolutely. You are bound together for life. You can divorce a needlessly competitive spouse. You can avoid your competitive friends. But, with a brother or a sister, you are fundamentally tied together. Your lives will always run in tandem, and you will always define yourselves by one another.

This sounds like an incredibly tricky balance. It is. Especially when, as sometimes happens, a parent clearly favours one sibling over another.

Oh, here we go again. This is because I got a bigger Christmas present than you nine years ago, isn’t it? Wait, are we siblings?

We certainly bicker like we are. Well, let’s not go there. We’ll throw the entire pass notes canon into confusion.

OK, phew. But mum definitely loved you more than she loved me.

Do say: “Sibling rivalry turns people into monsters.”

Don’t say: “Yes, but have you ever met an only child?”