Aims: To determine whether there is a correlation between maternal deprivation in infancy and adolescent delinquency.
Procedure: Bowlby studied a group of 44 juvenile thieves who attended a child guidance clinic, and subsequently compared them with a control group of 44 adolescents "who though emotionally disturbed, did not steal"
Findings: Fourteen of the thieves were classified as "affectionless", compared with none in the control group. Seventeen of the thieves had been separated from their mother for more than six months before they were aged five, compared with only two who had experienced such separation in the control group.
Conclusion: Bowlby concluded that there is a correlation between maternal deprivation in infancy and subsequent criminal behaviour in adolescence.
Strength: Taken by itself, the findings do indicate a link between maternal deprivation and criminal behaviour which is suggests that this is a field worthy of extra study.
Weakness 1: Bowlby does not seem to have considered other possibilities for the criminal behaviour - for example, the factors that caused the initial separation. Correlation != cause
Weakness 2: The study relies on the recollections of participants, which may be unreliable.