Bowlby’s theory of bereavement was essentially an extension of his account of separation anxiety. He saw anxiety as the realistic response to separation or threatened separation of a vulnerable individual from his care-giver.
This passage presents Bowlby’s core theoretical argument that separation anxiety is the fundamental model from which bereavement, grief, and adult loss responses are all derived.
, John Bowlby and Attachment Theory (Makers of Modern, 2014thesis