Sibling aggression is a common phenomenon which can lead to negative outcomes on the development of children. Aggression between siblings can possibly be explained by the quality of the sibling...Show moreSibling aggression is a common phenomenon which can lead to negative outcomes on the development of children. Aggression between siblings can possibly be explained by the quality of the sibling relationship and gender. The aim of the current study is to investigate whether anger in response to a sibling, as an indicator of the quality of the sibling relationship, is related to sibling aggression and whether gender plays a moderating role. A sample of 18 sibling pairs (oldest sibling: aged 10 to 18 years, M = 14, SD = 1.9) participated. The aggression between siblings was measured with the sibling version of the Conflict Tactics Scale, CTS2-SP. To measure anger in response to provocative behavior of the sibling a Virtual Reality (VR) task was used. The provocative behavior was believed to be controlled by their sibling but was actually an avatar. The participants were also asked if they believed if their sibling controlled the avatar during the VR task. The scores of the oldest sibling of the pairs were included. The results showed that anger in response to the sibling was not related to sibling aggression and that participants showed equal aggression towards their sibling. Also, no gender differences were found between participants in the link between anger and aggression, so gender did not play a moderating role. It seems that gender differences in siblings play a smaller role than in boys and girls for showing aggression. The results suggest that aggression between siblings might be more normal and accepted than aggression between boys and girls and that siblings may be more used to each other compared to non-family related children. However, further research is needed, to understand the phenomenon of sibling aggression even better in order to prevent it, since the consequences of sibling aggression can be profoundly serious.Show less