What makes being a sister so special, according to experts

Watch: The John Lewis Christmas advert is here

It’s December. Oxford Street is heaving with shoppers and visitors checking out the lights, and you’re on a mission to tick that last item off your list. Only, that last item is the most difficult to find – not because it’s sold out, but because you haven’t quite yet decided what it will be. Despite knowing her your entire life, she is the hardest person to buy for; she is your sister.

Depicting this very conundrum, John Lewis’ latest Christmas ad not only follows the thought process behind selecting the perfect present, it sees its protagonist, Sally, go back in time to various stages of her life with her sister: from childhood to the teenage years, to the early stages of adulthood. And it’s incredibly nostalgic.

For anyone who has, or has had, a sister they will know that there is a certain bond – a certain closeness – that is rarely found in other relationships. Sisters are simultaneously your best friend, your antagonist, your biggest cheerleader and your ultimate rival. But, is there a deeper reason behind the connection?

The John Lewis Christmas 2024 advert is one many of us will recognise: the story of sisterhood. (John Lewis)
The John Lewis Christmas 2024 advert is one many of us will recognise: a story of sisterhood. (John Lewis)

Counsellor and psychotherapist Georgina Sturmer says: "It’s possible that the sisterly bond is stronger due to the role that women and girls play in their families. They are often the drivers of social connections and family life."

This is supported by a recent study by Susan McHale of Pennsylvania State University. It showed that sister-sister pairings were overall more positive, and that it reinforced earlier findings that "sisters may serve as the glue that holds a sibling dyad together, at least until young adulthood."

The study also found that the emotional expressivity in sister-sister pairings was far better, and, in the words of the authors, "happiness is a feminine partner."

When it comes to why sisters bicker and argue (especially over clothes and "borrowed" items, as depicted in the advert), Sturmer says that is demonstrative of that closeness.

"We are able to show our true selves when we are close to someone – to be open about our anger, our frustration, our jealousy," she explains. "This is why we often bicker with the people we are close to, whereas we often wear a mask of civility and compromise in our everyday lives."

She adds: "This level of connection allows us to test boundaries. With our sisters, we typically assume that our bond will remain enduring, regardless of what happens. When we are not encumbered by a fear of rejection, it allows us to try different things and test boundaries."

Sturmer also states that "rupture and repair" are important features of human connection. "We often learn models for repair during our childhood. If we have been brought up in a household with a healthy and forgiving attitude to conflict, then it might be easy for us to resolve these issues. If not, then we might be left with anger or resentment.

"So another thing to consider, is whether we are behaving in a certain way because we assume that our sister will simply bear the brunt of it. We sometimes talk about 'displacement' when we displace our stress or anger onto something else or someone else. In this instance, our sister might be on the receiving end of behaviour that isn’t even really about her.

"If this is happening, start to notice your behaviour. Consider whether you would act in this way if you were with a friend or colleague – and whether your sister might in fact deserve a little more respect or kindness."

Again, the study by McHale demonstrated that once sisters have other responsibilities – be that a job, a partner or a family of their own – it becomes harder to keep that closeness, as your attention is divided.

It’s important, especially once you have both left home, to make the extra effort to maintain that closeness. Sturmer suggests that in order to combat this sense of drifting apart, sisters should schedule in regular time for one another – and ensure that there are no distractions.

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