By studying children whose primary caregiver had to go into hospital or away, Bowlby identified a three stage sequence of behaviours which was common to all. He labelled these behaviours protest, despair and detachment (PDD). Behaviour on return of the attachment figure was more complex. May involve anger, rejection by the child and/or ‘clingy’ behaviour. 

Suggested that attachment style is relatively stable. Attachment results from working models.  These tend to be stable because they develops over a period of years within the same family setting. As a result, they become habitual and automatic and so, operate largely unconsciously. They can change later in life if they lead to dissatisfaction, are demonstrated untrue by later relationship or are in conflict with social interchanges.  Even so, accomodation attachment working models will require strong and persistent discontinuity with experience.