Aim: study teenage delinquent behaviour and it's basis in MD
Procedure: Bowlby interviewed 44 delinquent boys whom had been referred to him. Parents also interviewed.
Findings: over 50% experienced 6 months seperation during 5 years of life. (In control group less than 5%).
32% affectionless psychopathy
Conclusion: Deprivation has social, intellectual and emotional affects on children.
One weakness of this study is that it is based on weak research- Bowlby conducted the interviews himself and knew in advance which children he expected to identify as affectionless psychopaths.
Bowlby writing to support MT theory - RESEARCHER BIAS