Someone check on the eldest daughters this Christmas.

"Are you happy or are you the oldest sibling and also a girl?"

It's the viral Tweet that sparked a flurry of commentary across the Internet. In one single, simple statement thousands (if not millions) of older sisters around the world felt seen.

From that moment on, a cohort of women were galvanised by an idea that being an older sister might just be the reason behind many of their behaviours, quirks or emotional challenges.

As TikToks popped up in response and experts weighed in, it was clear this idea had struck a chord with many citing 'Eldest Daughter Syndrome' as the best way to describe the phenomenon.

Many people said they felt a responsibility to look after their younger siblings, constantly felt a need to be diligent and an overwhelming pressure to succeed.

Take Christmastime, for example. You'll find oldest sisters counselling all the other family members on what presents to buy each other, rather than them just *thinking up an option themselves*. They'll be telling the cousins the Wi-Fi password when they all come for Christmas lunch, and they'll be dancing around the kitchen fixing the trimmings so mum doesn't burn them.

Basically, older sisters have a lot to unpack and they've finally found their platform to get it off their chest.

So, what is 'Eldest Daughter Syndrome'? Is it even a real thing?

Does your birth order predict your personality? Listen on This Glorious Mess. Post continues below.

We spoke to Doctor of Clinical Psychology Kimberly Stirling who agrees that there may be some broad patterns and behaviours commonly attached to an eldest daughter in the family dynamic.

"In some families there may be a dynamic where the older sister becomes an additional 'caregiver' or 'helper' alongside the parent," says Dr Stirling.

"When this is the case, that sister may develop beliefs about her inflated responsibilities to others, and her sense of being loved and 'enough' may be tied to how 'helpful', 'unproblematic' or 'perfect' she can be. Alternatively, if most of the family focus is on younger siblings, she may learn to be hyper-independent from an early age."

@israajnasir @viennaayla captures the eldest-daughter-syndrome so well. Hilarious reminder to break the cycle! #eldestdaughterthings #generationalcyclebreaker #eldestdaughterproblems #therapysessions #oldestdaughter ♬ original sound - Israa Nasir

"Older siblings may be expected to 'compromise' more or understand the perspective of their younger siblings who may not have the developmental ability for certain things yet, which may then reinforce the belief that they should always be thinking of and understanding others, or putting others' needs first," says Dr Stirling.

"If these care-giving behaviours are then rewarded in the family system, the behaviours may increase and become part of that siblings' 'role' in the family."

If you're an older sister, you might be reading this and nodding your head.

It may be that when you reflect on your childhood and growing up with younger siblings, you recognise these traits and behaviours within yourself.

But does 'Eldest Daughter Syndrome' really have a flow on effect into your adult life?

Watch: Oldest child syndrome. Post continues below.

"This will look different across cultures," says Dr Stirling. "Whether there is direct pressure or expectation placed on the older sister by parents, or whether this internal expectation has been shaped over time through reward of 'helpful' or 'responsible' behaviours, they may develop a sense of over-responsibility for things that are not theirs to hold."

"A sense of inflated responsibility can carry forward into their adult life and be observed as difficulty setting healthy boundaries, difficulty with assertiveness or saying 'no' to things without over-explanation, taking on other people's challenges as their own, or difficulty prioritising their own needs or wellbeing.

"They may have difficulty asking for help or sharing reasonable tasks with others for fear of being a burden."

While the jury may still be out on whether the 'Eldest Daughter Syndrome' is a clinically classified term, it's safe to say there's a growing number of women who believe it to be true.

With that in mind, if you're a younger sibling, pop on the phone and call your big sis today and tell her you love her.

Feature Image: Getty.

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