Bowlby's maternal deprivation hypothesis

Bowlby concluded from this study that maternal deprivation could have very serious effects on the child, including producing affectionless psychopathy. He also suggested that early maternal deprivation during the critical period in the formation of the attachment could have long lasting negative effects that were observable several years later.

More support for Bowlby’s views came from a piece of classic research conducted by Lorenz (1935). In this study, Lorenz became ‘mother’ to a brood of goslings. It was already known that many birds attach themselves to the first figure they see upon hatching and persist in this attachment, and Lorenz’s work confirmed this. The phenomenon is called imprinting, an ethological concept taken from embryology. During pre-natal development, there are short periods when an individual is especially vulnerable. These times are called ‘critical periods’ and the effect is an imprint. Imprinting is an example of an instinct, an inherited behaviour pattern that predisposes an individual to certain forms of learning at critical times in development. Bowlby suggested that attachment behaviour is a kind of imprinting and is irreversible.

However, it is possible that factors other than the absence of the mother (lack of parental supervision for example) could have been responsible for the delinquency. Rutter (1981) found that it was the circumstances surrounding the loss that was most likely to determine the consequences rather than the loss itself; that it might simply appear to be deprivation that was causing later difficulties, whereas in fact the difficulties were due to factors associated with the deprivation. Rutter et al. conducted a study of over 2000 boys aged between 9 and 12. They and their families were interviewed, and the relationship between separation and delinquency was looked at. It was found that if the separation was due to the physical illness or death of the mother, there was no correlation with delinquency. However, if it was due to psychiatric illness or discord within the family, then the boys were 4 times more likely to become delinquent.

As well as this, in more recent studies of adopted children, Tizard has found that older children can form satisfactory new relationships with adults despite the lack of earlier attachment.