Sibling relationships and sibling rivalry

A big life event, such as the arrival of a new baby, can be unsettling for an older child (NHS, 2023). A new sibling can bring joy and excitement. However, the older sibling may feel jealous, angry, sad or resentful (Anna Freud, no date).

They might display these emotions in a variety of ways. The older child might (Anna Freud, no date):

• physically hurt the baby
• say they want the younger child to go away
• be challenging with the parents or in childcare settings, although loving to the baby
• show developmental regression, maybe even copying behaviours of their younger sibling
• become withdrawn

Even if this behaviour is challenging, giving reassurance and attention to the older child can help them get along with their new sibling.

What is sibling rivalry and why does it happen?

Sibling jealousy is common. It is thought to be a natural reaction to the fear that a younger sibling might take the older child’s place (Hart, 2022; Szymanska, 2020).

Our ancestors depended on their mother for food and protection, so an older sibling might see a new baby as a threat to their survival. They may feel this way because the new baby means they have to share the mother or primary carer’s milk and care (Hart, 2022).

Researchers suggest that this instinctive response could be there by nine months old (Hart, 2022).

Sibling rivalry can be worse when the younger child plays a negative role (like grabbing toys for themselves) rather than a positive one (Qian et al, 2024).

On the other hand, if the older child is able to control their emotions, it can lead to a better sibling relationship (Su-Russell et al, 2024).

How can you help your children get along?

Siblings get on better when there is no favouritism from parents (Her et al, 2021). Older children who are more secure in their relationship with their parents, and who have their needs met, are less likely to display sibling rivalry (Murphy et al, 2019; Su-Russell et al, 2024).

When parents’ expectations are too high of the older child, it can lead to more jealousy. For example, they might think the older child should ‘grow up’ and help with care of the younger child as soon as they are born (Qian et al, 2024).

But if parents instead have more reasonable expectations of the older child, they are less likely to be jealous. They are also more likely to be a positive role model (Qian et al, 2024).

On a practical level, you could help older children get ready for the arrival of a new sibling by (Anna Freud, no date):

• Explaining that there’s going to be a new baby in the family.
• Reassuring them and being honest about what it will be like. Ask at your local library for books about having a new brother or sister.
• Asking the older child to talk about how they feel about a new baby.
• Watching how they play with toys or dolls. They may act out scenarios involving family life or babies. This can give clues about how they’re feeling and provide opportunities to talk about family changes.
• Giving the older child lots of attention and one-on-one time.
• Involving them in preparing for the baby. Let them help choose a name or get the baby’s things ready for them.

After the baby is born, it may help to (Anna Freud, no date):

• Ask them how they’re feeling, and let them know these feelings are normal.
• Give them reassurance, attention and love.
• If they want to, involve them in simple supervised tasks to help ‘look after’ the baby, and thank them for helping.
• Acknowledge and reinforce positive behaviours towards the baby, like gentle touch and talking.
• If possible, ask family and friends to help so you can spend one-on-one time with the older child.

Benefits of having siblings

Siblings play a unique role in shaping each other’s emotional empathy. If the child has a sibling who has a positive impact on them, when they are older they will be more in tune with how others are feeling (Gungordu & Hernandez-Reif, 2020).

Even if siblings are different, their similarities can provide emotional support throughout their lives (Her et al, 2021).

Regular family activities, such as storytelling, singing and playing, can help improve social and emotional health (Muñiz et al, 2014).

Having siblings can also reduce the chance of developing asthma and infections. This is because siblings build up more useful bugs in their airway and gut. One study found a younger sibling was less likely to have asthma if they were close in age to their older sibling (Christensen et al, 2022).

Does it make a difference if the siblings are the same sex?

As far as developing empathy, it doesn’t matter if the siblings are male or female. This is because having a sibling helps understanding of someone else’s point of view (Gungordu & Hernandez-Reif, 2020).

Having a sibling of the same sex can cause competition and comparisons between them. But siblings are more likely to look up to each other if they are the same sex (Her et al, 2021).

Does the age gap make a difference?

Siblings are more likely to have similar personalities if they are close in age (Her et al, 2021).

Younger siblings are likely to compare themselves to the older sibling. This comparison might worry them, especially if there is a small gap in age (Her et al, 2021).

Are there any drawbacks to having siblings?

Jealously and conflict can be negative experiences of having a sibling. Knowing how valuable this relationship will be for life, parents can support their children by helping resolve conflicts and emphasising the benefits of having a sibling (Her et al, 2021; Szymanska, 2020).

It is useful to remember that sibling relationships can change over the course of a lifetime (Her et al, 2021). So even if they are not close as children, they might be when they’re older.