It took all of 30 seconds to go from, “You can’t play with me,” to the older sister belting her younger brother on his back with her Barbie doll. There were many tears, a Timeout, and a forced apology, as well as a ban on all play dates for the rest of the week.

Sibling conflict and rivalry is all too familiar to many families. With arguments ending in violent outbursts, crying and an effort to separate the sparring kids, parents often wonder if their children will ever get along. While the cliches in popular culture frequently portray negative relationships between siblings, being aware of the long-term effects of this kind of behaviour is important for parents.

Recent paediatrics studies published in the United States National Library of Medicine reveals being bullied by a sibling can be just as damaging to a child’s mental and emotional health as being bullied by another child in the playground or at school. The home is meant to be a safe space for each individual member of a family. When bullying occurs there, children will feel helpless, anxious and extremely unhappy, which can manifest into more serious issues of depression and other mental illnesses as they grow older.

It is important to note that there is a difference between bullying and rivalry – bullying is more infrequent than rivalry. Sibling bullying has an element of aggression verbally and physically that rivalry does not. Violent words, manner of speech, as well as physical actions and intent are all signs of bullying. Rivalry lacks this ongoing element of aggression and nastiness and, according to Sherri Gordon of Verywell Family,

“This bullying…stays with the victim for years to come.”

Sibling relationships are shaped by a multitude of forces. While family dynamics and composition play a role, as do extramarital factors, every child is unique. Research indicates that siblings can be as different to one another as two completely unrelated children.

A study by Cambridge University conducted on a group of children over five years investigated the nature of sibling rivalry. It discovered siblings have an overall positive impact on each other, even if their relationship isn’t completely happy.

According to the study, mild rivalry between siblings can be beneficial to both children and will not often have long term impacts. It is when this behaviour is sustained and occurs over a lengthy period of both siblings’ childhoods that issues can arise. These negative impacts can result in long term problems such as:

• Difficulty with relationship-building later in life (romantic and non-romantic)
• Behavioural problems
• Difficulty in social situations
• Extreme competitiveness
• Difficulty accepting criticism and being a “sore loser”

A healthy amount of rivalry can boost a number of positive elements in the younger sibling’s early development. Older children expose their younger brothers or sisters to emotionally rich language particularly when engaged in an argument or competition with the younger sibling. The Cambridge study found, that by the age of six, younger siblings could converse with their older siblings about emotions on equal footing rather than at the level of other six-year-old children.

It is in the space of sibling relationships that children learn the most about conflict resolution and prevention, as well as testing their social skills both before and during their primary school years.

Michele Fry of Greatschools.org states, “It’s where children learn to cooperate and compromise – skills they carry into adulthood.” With a sibling, the boundaries and limits of social interaction which are modelled by parents can be tested and experimented. Fry explains, unlike with a school-yard friend, a sibling won’t leave their brother or sister if they get called a name or teased by their sibling. In this way, siblings continually learn from each other about how to interact with their peers.

What is important to note is that this testing of social interaction between siblings needs to be monitored by their parent – what can be seen initially as pushing the boundaries can quickly escalate into abuse if the behaviour continues. In this situation the parent should intervene to reinforce positive behaviours and mediate conflict if the children can’t do so between themselves.

The role of the parents

Parents have one of the biggest influences over the relationship between their children. Dr Sylvia Rimm, psychologist and director of the Family Achievement Clinic, outlines what is important for parents to know about rivalry between their children.

1. Labelling

Referring to your children as the “sporty” child, or the “creative” or the “academic” child can cause significant problems for both children. While this may initially seem like a good way to encourage and guide children into areas they may show a natural propensity for, it can have adverse effects.

Dr Rimm states, labels reinforce differences between siblings and can encourage competitiveness for certain titles, commenting;

“When children are labelled best in a domain, they often do their best to prevent another sibling from encroaching on their domain.”

Michele Fry also highlights the negative impact on self-development that labels can cause. Children who are labelled early will often live up to these labels and be disinclined to venture into other areas. It limits their capacity for developing an identity separate to the one they have had reinforced constantly by their parents and siblings because of the label they were given at an early age.

2. Gender, age and family dynamics

Gender, age and family dynamics are also important to consider as parents when assessing the level of sibling rivalry and encouraging positive sibling relationships. Rivalry is generally harmless and something that most siblings grow out of by the time they have reached their late teen years. Dr Rimm outlines the following instances where rivalry can escalate or cause prolonged problems for both siblings:

• Two close-aged children of the same gender e.g. two sisters 18 months apart
• The younger sibling following directly after a very talented oldest child
• The “baby” of the family

It’s also important to remember that siblings spend more time together than they do with their peers. Growing up, living in the same household, going through shared family experiences, all contribute to siblings knowing one another in a way that peers do not. While this can be positive for relationship building into the future, it can also have a negative impact for rivalry and bullying. A sibling will know their brother or sister’s weak spots and sensitivities more than schoolyard friends might.

Professor of Applied Family Studies, Laurie Kramer, states,

“Children can take advantage of vulnerabilities and make the other one feel bad with a word.”

This kind of emotional rivalry or bullying is harder for parents to monitor but can be extremely damaging long term on self-esteem and development particularly if it occurs frequently during teenage years.

What are the long-term impacts?

According to Mike Bundrant, psychotherapist and co-founder of the Neuro-Linguistic Program, sibling rivalry and aggression can have the same long term as bullying by a peer. In the teenage and young adult years, it can result in a deterioration of self-esteem and sense of personal identity. This usually arises in cases where sibling rivalry takes the form of frequent humiliation or a desire to embarrass one sibling in a public setting.

Sibling rivalry can continue into adulthood and be a feature of a family relationship that never goes away. As adults, there can be competition surrounding financial and employment success, marital and familial situation, and on the successes of the sibling’s own children.

Siblings are usually the closest and most long-lasting family relationship in anyone’s life. Siblings will grow old together in a way that a parent child relationship doesn’t usually provide. If this relationship can be nurtured from a young age, siblings may have a better chance of maintaining a supportive and healthy relationship into adulthood as they create their own lives away from the family home.

Educational consultant and parenting coach, Chrissy Khachane, suggests the following tips for creating positive sibling relationships:

1. Support cooperative play.
2. Teach each child to respect the differences between one another.
3. Talk through poor behaviour with each child to promote understanding in difficult situations.
4. Teach your children to resolve conflict.
5. Reinforce boundaries with private conversations.
6. Give each child individual attention away from his/her sibling.
7. Modelling healthy relationships by validating each child’s feelings from time to time.
8. Teach them the difference between tattling and seeking help.
9. Give each child their own physical space.
10. Teach your children to recognise and label their own emotions.
11. Family rituals and traditions are a great way to foster healthy sibling relationships.