Wednesday Wisdom

April 17, 2024

Sibling Influences

By Patrick Cragg

Sibling Influences


A friend of mine recently asked me a question using terms I haven’t heard since I was at school. “Now that you’ve had two children,” she asked, “do you believe in nature or nurture?” It’s a question all parents must ask themselves at least once a week: how do you explain why your children are the way they are? And once a sibling arrives it gets twice as complicated. Because these two children, both made from what you might assume are the same ingredients and raised by the same parents…why are they so different from each other?

I told my friend I was on the side of nurture as the more important factor in shaping children. It’s quite a fundamental belief for me, in fact, that the environment in which children are raised, and the opportunities and support they receive, play a bigger part than innate or “natural” abilities and preferences. But, I told her, “the raw materials in each sibling turn out to be a lot more different than you might think.”

One child can sing in tune; the other can’t. One picked up reading very quickly; the other has a head for numbers. One has patience, enjoys rules and structure; the other wants to move through the day at their own chaotic pace. One moment they’re the best of friends, the next they’re wrestling around the floor. Whatever opportunities you give your children and whatever choices you made in their early years, a lot of this stuff just seems inbuilt.

Families live out a complex dance of similarities and differences, of unity and division. We might live in a shared space but each member tries to establish their own identity and cling onto it. We want our children to share our values and feel a sense of belonging, but also to grow into themselves, to be their own person. We try to treat them equally but also respect their differences and their individual wants and needs.

And so the great pleasure, and the great mystery, of being a parent of siblings is watching them grow around and apart from each other, like two tall plants flowering in the same patch of forest.

But what we hope most of all for our children is that they grow up to support each other. That their shared childhood is the platform for a healthy, loving future relationship, and their differences evolve into a sense of appreciation for each other. As an adult, I’m very glad for my relationship with my sister: the memories we have of festival-going, gigs and theatre trips; the shared emotional bond with our family; and now being uncle and aunt to each other’s children.

Not having a brother myself, one aspect of my two boys’ relationship that confounds me is their addiction to jumping on, pushing past and generally Avengers-ing each other at every opportunity. Luckily thanks to Tooled Up I’ve learnt that “rough and tumble play” is important for emotional regulation later on – find the podcast link in the Tooled Up box below!


There has been plenty of research into sibling relationships and the effect they can have on future emotional wellbeing (and you can find plenty of it within the Tooled Up platform).

Children spend more of their out-of-school time with siblings than anyone else, including parents and friends, according to Professor Susan McHale of Penn State University. In her words, “Siblings are most people’s longest-lasting relationships—from early in childhood through old age. This means they can understand you in ways other people can’t.” It also means that, as parents, we should think about the time that siblings spend together. I’m particularly interested in the observation that sibling relationships are “rarely clear-cut”: it’s normal for a feeling of conflict or rivalry between siblings to co-exist with deep love and loyalty!

A University of Cambridge study published in 2011 found that relationships between siblings don’t have to be all sunshine to have a beneficial long-term effect. The interaction between siblings helps to promote social awareness, what the researchers called “emotional scaffolding” that helps children construct stories about their own emotions and mental state. Even sibling rivalry and teasing can be beneficial provided it isn’t taken too far.

The sense of the sibling as an "ally" in the family, especially as someone who has been raised in the same family and shared the emotional environment of the home, can be a vital source of support as we get into adulthood. According to Laurie Kramer of Northeastern University, “No one else will know what it was like growing up with your parents in your household, and that sense of being understood by another person can be incredibly powerful.”

So there are plenty of reasons to give your children time and space to interact with their siblings, planning activities together and helping them to talk about the emotions that come out of sibling time, both positive and negative.


Parents have an important role to play in nurturing positive and supporting sibling relationships. We can’t just assume that our children will figure it out by themselves. Part of that is role modelling the type of behaviour we hope to see in our children. If you want them to develop empathy, demonstrate and talk about empathy. Comment on and praise kindness between your sibling when it occurs. An eight-year-old won’t instinctively know how to play with a four-year-old: it’s a totally different type of play from what they get from their peers at school, and we might need to train them a bit to prevent frustration and falling out.

Conversely, it’s a great idea to give siblings one-on-one time so long as they can see this is distributed fairly! For the more “grown up” sibling, being taken for a special trip that the younger one might not be ready for – a movie or football match, perhaps – is a big treat and shows that you appreciate your children’s differences as well as expecting them to conform to family rules.

Avoid labelling your children or suggesting that you have fixed ideas about which of them is “good at” certain things. This can be perceived as a preference for one and criticism of the other.

Keep the lines of communication open! Talking openly about family values, about expectations for behaviour, about the decisions you make that might affect different children differently, all help to combat perceptions of unfairness.

All siblings can experience negative feelings around their relationship with their brother or sister, and what they perceive as their position within the family. Feelings of rivalry are common for siblings, and many struggle with the feeling that another sibling is the “preferred” child, however unfounded that may be.

For siblings of disabled children, these negative emotions can be particularly acute. It’s inevitable that the child whose day-to-day needs are more pressing and complex will often seem to get more parental attention, while greater responsibility and expectation, as well as the expectation of greater responsibility in the future, fall on their sibling.

The charity Sibs provides support for children and adults with disabled siblings, and their website contains a wealth of practical advice that would be useful reading for children and parents alike. Sibling Support is a charity dedicated to the even more difficult circumstance of sibling bereavement, giving support with family relationships after the loss of a child.

Many people who are siblings have a sense that their parents have a favourite child. Research suggests that, in fact, it’s normal for parents to have a favourite, but that there are negative consequences for both the preferred and the less favoured child. Of course, sibling rivalries are at the heart of much of the literature and TV we consume! This interview with psychologist Genevieve von Lob explores the phenomenon of favourite children and how parents can avoid it.

Are you a Tooled Up member?

Tooled Up hosts a wealth of valuable and accessible information and advice on promoting and celebrating healthy sibling relationships.

Our support begins before the new sibling even arrives! Explore this list of books to help children prepare for a new sibling, and these tips for supporting siblings when a new baby comes.

Listen to this interview with Dr Kathy Weston and Professor Susan McHale on promoting sibling harmony, and read our tips for promoting healthy sibling relationships. Our Celebrate Your Sibling activity can be an antidote when the quarrelling seems to be taking over!

We also have expert input on some of the specific circumstances that can make being a sibling particularly challenging: sibling bullying, sibling bereavement and supporting a sibling whose brother or sister has an eating disorder.

And don’t forget my personal favourite: our expert webinar on the value of rough and tumble play!