Sibling Conflict

Sibling Conflict

A common issue that I encounter is sibling conflict. As an only child, it was not a natural concept for me to grasp but one study quickly came to mind and has guided my interventions ever since. The Robbers cave experiment conducted by Sherif et al (1954) explored intergroup conflict and co-operation.

The experiment involved 2 groups of 12-year-old boys who were situated on a large scout’s camp. The groups were sperate from each other and unaware of each existence. Over the first week, each group were given tasks that required them to work together resulting in bonding and the establishment of group identities, the “Rattlers” and the “Eagles”.

Over time the groups started to become aware of each other’s presence. This led to discussions of defensiveness about camp facilities they enjoyed like the baseball field. The groups also started to ask about competitions to be held with the other group leading to an increase in enthusiasm when completing potential competitive tasks (e.g. tent pitching, swimming).

The experimenters then introduced competition amongst the groups in the form of group and individual tasks that were scored, and prizes awarded accordingly. When the group’s first met each other, they were disrespectful towards each other with name-calling, taunting and antagonising behaviours. The Eagles were victorious in the competition (aided by the researchers) which lead to vandalism of each other’s camps, Rattlers stealing the prizes awarded to the Eagles and close to full-blown physical conflict.

Now that there were considerable tensions between the 2 groups, researchers set out to heal the relationship and reduce the friction. Both groups were presented with reconciliatory opportunities including watching a movie together, having a fireworks night together or engaging in medial task together. This didn’t work. In fact, tensions if anything continued to flare.  

Researchers then decided to introduce in superordinate goals (goals that require the cooperation of two or more people or groups to achieve, which usually results in rewards to the groups). These included a water crisis in which the water system was turned off and blame don vandals. Both groups separately discovered the same full water tank that required a group effort to clear the faucet and gain water. The groups made suggestions to each other, assisted in clearing the faucet and rejoiced and the ensuing release of water.  With the introduction of more superordinate goals, tensions lessened and both groups left camp on the same bus with no distinct seating arrangements of their group identities.

Although this is a wonderful study on the development of intergroup conflict it does have many flaws, least of which are the statistical recording and analysis of results. What results do exist show that not all the members of the in-groups were favourable towards the out groups at the end and not all variables could be controlled in such a field study.

The big lesson I find from such a study is mirrored in the comments of Tavris (2014);

Yet Robbers Cave was and remains important for its central ideas: At the time, most psychologists did not understand-and most laypeople don't understand even today-that simply putting two competing, hostile groups together in the same room to, say, watch a movie won't reduce their antagonism; that competitive situations generate hostility and stereotyping of the out-group; and that competition and hostility can be reversed, at least modestly, through cooperation in pursuit of shared goals. That's the story of Robbers Cave: it was true then, and it's true now.

Sibling conflict is often the result of competition over resources and parental attention. Even though conflict or lack thereof is often attributed to the relatedness between the siblings, we can see from Robbers cave that two groups who are similar can still manifest conflict between each other. This was highlighted in a study by Tanskanen et al (2017). Tanskanen and the team reviewed conflict between full siblings and half-siblings. It was hypothesised that as half-siblings only shared one biological parent that there would be less conflict between them. Results found that conflict levels were higher in full sibling arrangements as they competed over both biological parents.  

Resources and attention are in limited supply and conflict are unavoidable. However, as shown at Robbers cave, the tension can be lessened, and this continual regulation allows for a healthy balance of conflict and altruism. The key is the development of superordinate goals which can be done through highlighting the strengths of the individuals within the family constellation and basing goals on family values.   



Sherif, M., Harvey, O. J., White, B. J., Hood, W. R., & Sherif, C. W. (1988). The robbers cave experiment. Intergroup conflict and cooperation.

Tanskanen, A. O., Danielsbacka, M., Jokela, M., & Rotkirch, A. (2017). SIBLING CONFLICTS IN FULL- AND HALF-SIBLING HOUSEHOLDS IN THE UK. Journal of Biosocial Science, 49(1), 31-47. Retrieved from

Tavris, C. (2014, Thinking critically about psychology's classic studies. Skeptic, 19, 38-43,64. Retrieved from