Stages of attachment developed by Schaffer and Emerson
1. Stage 1: Asocial stage (0-few weeks old) - the baby does not really distinguish between human and non-human objects
2. Stage 2: Indiscriminate attachment (2-7 months old) - the baby prefers familiar adults but is happy to be comforted by any adult
3. Stage 3: Specific attachment (7 months onwards) - the baby now prefers one specific adult and shows separation anxiety and stranger anxiety
4. Stage 4: Multiple attachments (8/9 months onwards) - the baby enjoys being with people they are familiar with rather than just one specific caregiver all the time