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Identified: The Families with the most Sibling bullying

  • Sibling bullying does have an impact on mental health later in life, and parents and health professionals need to take it seriously to prevent it.
  • There are characteristics in families that make sibling bullying more likely.
  • Family constellation and early experiences predict families with more sibling bullying.

Sibling bullying does have an effect on mental health later in life for both the victims and the bullies, it needs to be taken more seriously by parents and healthcare professionals. There are families where sibling bullying is more likely and can be prevented – says researchers in the Department of Psychology at the University of Warwick.

Prof Dieter Wolke and PhD student Slava Dantchev have previously found that sibling bullying does have an effect on mental health later on in life in previous research but now they have identified the factors in a family that sibling bullying is more likely to occur in their paper ‘Trouble in the Nest: Antecedents of Sibling Bullying Victimization and Perpetration’ published in Developmental Psychology today (14th Feb 2019)

Using the Avon Longitudinal Study of Parents and Children (ALSPAC, also known as the Children of the 90s study), they identified factors in families that may predict sibling bullying, as the victim and the perpetrator.

The factors fell into four categories:

1. Structural family characteristics - e.g. birth order, number of children in the household, number of older brothers/sisters, marital status in the family, education level and financial difficulties.

2. Parental and parenting characteristics - e.g. postnatal mental health, maternal bonding, conflicting partnerships or domestic violence.

3. Early social experiences – e.g time spent with siblings, aggression between them and peer bullying

4. Individual differences – e.g. gender of child, child temperament and IQ

There were 3 different types of bullying monitored – including: Physical, psychological and social.

The researchers analyzed data from 6,838 British children born in either 1991 or 1992. 28.1% of them were involved in any kind of sibling bullying.

Psychological bullying was the most reported type of bullying, and males bullied their siblings more often than females.

Those who most often perpetrated bullying against siblings were first-born children, those growing up in families with more children at home, who had parents who did not effectively parent or themselves had conflicts with each other and the children showed early on aggressive tendencies.

Most interesting, whether the family experienced financial difficulties, came from a higher or lower social class, two or single parent household or whether mothers had higher or lower levels of education did not predict sibling bullying.

Findings suggest sibling bullying is an evolutionary driven strategy towards maintaining or achieving social dominance, and older siblings are at particular risk of initiating sibling bullying.

Professor Wolke and Slava say parents may benefit from education about how to deal with resource losses for first-borns, and how to manage them in fostering improved sibling relationships. Interventions that may help both parents and children reduce aggression and bullying might be useful for affected families.

Professor Dieter Wolke of the Department of Psychology at the University of Warwick comments:

“This is the first study that has looked at risk factors for sibling bullying from pregnancy to early adolescence. Sibling aggression is driven by loss of resources for firstborns and later born defending their need for resources such as parent attention or material goods. Sibling bullying has a class blindness: it is as much an issue in well to do families as those who are financially just getting by.”

First author Slava Dantchev adds:

“This and our previous findings of the adverse effects of sibling bullying on mental health make it clear that parents may benefit from information on how to identify and deal with sibling bullying”


14 FEBRUARY 2019


Full text of the article is available from the APA Public Affairs Office

Children of the 90s

Based at the University of Bristol, United Kingdom, the Children of the 90s study (also known as the Avon Longitudinal Study of Parents and Children or ALSPAC) is a long-term health-research project that enrolled more than 14,000 pregnant women in 1991 and 1992. It has been following the health and development of the parents and their children in detail ever since and is currently recruiting the children and the siblings of the original children into the study. It receives core funding from the Medical Research Council, the Wellcome Trust and the University of Bristol. Find out more at For media enquiries, please contact

This research was also supported by the NIHR Bristol Biomedical Research Centre.


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