"Oppositional behavior" refers to a pattern of challenging or defying authority figures, often showing anger or disobedience towards rules or requests. Full definition
Furthermore, when parents express low levels of support, the negative influences of deviant peers on the development of oppositional behaviour increase [26, 53]. (link.springer.com)
So, what we looked at and what we matched the two kids on were things like previous aggressive behaviour, previous oppositional behaviour, different parenting styles, their level of pro-sociality, their exposure to bullying at school, their approach to the school, their motivation to learning and other variables. (teachermagazine.com.au)
IO: The key findings were that, as we predicted, the students with better relationships (self - reported and teacher - reported) versus those with worse relationships were more prosocial and they were also less aggressive and less oppositional, or showed less oppositional behaviour. (teachermagazine.com.au)