Are young people encouraged by their criminal brother or sister?

And, ‘how do I survive my criminal sibling?’

‘The research did indeed reveal that brothers influence each other's criminal behaviour and sisters likewise. However, this does not apply for mixed brother/sister pairs. There is also a difference between early and late adolescence. In early adolescence, mainly sisters appear to influence each other's delinquent behaviour, whereas their mutual influence decreases as they become older. The opposite is true for brothers: a significant influence on each other's delinquent behaviour does not occur until late adolescence. The influence of delinquent behaviour from the best friend also appears to increase during adolescence.’

Who exerts an influence on teenagers?

‘Young people's lives take place in different social domains, such as family, school and peers. All of them have a considerable influence on young people's behaviour and therefore also on their possible involvement in adolescent delinquency as well. However, the importance of each of these domains changes over the course of adolescence. According to the interactional theory of Terence Thornberry, the family has the most influence on young adolescents, whereas among older youths, the influence of school and peers increases. The theory says little about the roles of siblings,even though these can also be an important factor in the lives of young people. We investigated that using the data of 600 pupils in secondary education that was taken from the longitudinal RADAR project.’

A sibling is often simultaneously a family member and a peer. What sort of effect does that have?

‘The research threw light on two contradicting expectations about the role of siblings. On the one hand, they are members of the family and the process of becoming independent could lead to a decreasing influence of siblings. On the other hand, siblings can be viewed as contemporaries of each other, and therefore an increasing effect could be expected. For girls and sisters, the first expectation holds more, and the second more for boys and brothers.'

How can this research be used in practice?

‘The outcomes are important for prevention and interventions focused on families of adolescent delinquents. Future research could examine the entire family in greater detail, including all siblings. It would also be valuable to find out more about the underlying mechanisms that lead to siblings exerting influence on each other's delinquent behaviour.’

Publication details and further reading

Huijsmans, T., Eichelsheim, V., Weerman, F., Branje, S. & Meeus, W. (2018). The Role of Siblings in Adolescent Delinquency Next toParents, School, and Peers: Do Gender and Age Matter? Journal of Developmental and Life-Course Criminology.