Finally 20% were found to be avoidant (the infant does not seek contact with the caregiver and shows little distress when separated). It was suggested that depending on the type of attachment there would be different positive and negative effects in the child's future. In particular Ainsworth suggested that the security of attachments had an influence on later development and that children from securely attached relationships would show a whole range of positive characteristics including sociability.
Bowlby (1953) claimed that breaking the maternal bond with the child during early childhood can have serious negative consequences on its emotional, intellectual and social development. This is known as the maternal deprivation hypothesis and was originally formulated by Bowlby after his own study involving forty-four thieves (1946). Bowlbys participants were eighty-eight children who had been referred to the child guidance clinic where he worked. Forty-four of these were referred to the clinic because they were stealing and the remaining forty-four because of emotional problems. It was found that 32% of the thieves could be described as "affectionless psychopaths" compared to 0% of the other group. In addition, 86% of those thieves diagnosed as affectionless psychopaths had experienced early childhood separation compared to just 17% of the thieves without this diagnosis. This study therefore clearly suggests that maternal deprivation can lead to negative consequences, in this case lack of emotional development.
There are, however, arguable gaps in Bowlby's research allowing for questions to be raised concerning his hypothesis. Not only is the research now dated but also there were a number of flaws in the study. For example some of the children had had only been separated for very short periods of time, as little as long week and so it is unlikely that this is long enough to cause such serious conditions.