Strengths-
Scientific = research done by behaviourists is usually scientific = highly replicable = easily testable because it's about easily observed behaviour
Practical application = understanding roles of observational learning in aggression has helped the violence, we can use classical conditioning as mental disorder therapy and operant conditioning is used to modify compliance to medical recommendations
Weaknesses-
Reductionist = reducing something complex like behaviour, to something simpler like conditioning
By ignoring mental processes, behavioural theories are generally guilty of reductionism, ignores other aspects, e.g. biology, social, cognitive and so putting aggression down to a learned response = reductionist
Ethics = it's not ethical to forcibly alter behaviour and use punishment/manipulation to shape behaviour = unethical