Bowlby (1969) proposed that millions of years of evolution had produced a behaviour that is essential to the survival chances of human infants. Humans are born helpless and totally dependent on the actions of a caregiver for food, warmth, shelter and safety for their well being and survival. If babies did not behave in a way that made it more likely an adult would care for them, and if adults did not become attached to babies, then human infants would not survive to reproductive age. Therefore natural selection has passed on genes that lead to attachment forming behaviours.
The innate nature of attachment was illustrated by Lorenz (1952) in his studies of imprinting in geese. Lorenz hatched two groups of geese eggs - one group stayed with their natural mother and the other group were hatched in an incubator. The first moving thing the incubator group saw when they hatched was Lorenz himself, and the geese immediately started to follow him around. When the incubator geese and natural mother geese were mixed together, they would quickly separate into the two original groups and follow either Lorenz or their natural mother. Imprinting of this nature in animals has a clear survival advantage as it keeps them close to their mother who would naturally protect them from predators and increase their chances of survival.
The types of attachment an infant experiences form a template for that infant’s future attachments. This template is called an internal working model and plays a role in guiding future adult relationships.
Bowlby’s theory has three main features:
1.Infants and caregivers (usually mothers) are innately programmed to become attached.
2.Attachment is a biological process that takes place during a critical period or not at all.
3.Attachment styles developed in infancy play a role in later attachment styles through the continuity hypothesis.
Critical period for attachment formation
Most developmental processes take place during a critical period. This is a time frame or window of opportunity in which development of a behaviour or characteristic occurs. If the behaviour does not happen during the critical period then it may well not develop at all. Bowlby argued that there is a critical period between the ages of birth and 2.5 years (0-30 months) in which conditions must be right for an attachment to form, and if it does not form in this time then it is not possible to develop thereafter.
Rutter et al (1998) studied Romanian orphans who had been placed in orphanages with minimal adult contact. When these children were adopted by US and UK families in their first year of life, they were able to form strong and stable attachments with their adopted parents. Bowlby’s theory argues that after 2.5 years of age the infants would not be able to form an attachment, however when older infants were also adopted by US and UK families they made slower progress than their younger counterparts, but they did develop attachments. This shows that attachments can be formed outside the critical period, but that they develop much more slowly, and that the idea of a critical period outside of which an attachment cannot be formed should be modified to a sensitive period during which attachments form more easily.
Bowlby argues that infants form a single special attachment with one primary attachment figure, usually the mother. This is called monotropy (moving towards one). Other attachments may develop in a hierarchy below this. An infant may therefore have a primary monotropy attachment to its mother, and below her the hierarchy of attachments my include its father, siblings, grandparents, etc.
The idea of monotropy and hierarchy is supported by research into attachments formed by the Efe tribe of Congo. Efe women share the care of infants in the tribe and take turns to breast feed them, however the infants return to their natural mother at night and form a stable bond with the mother.