Multiple attachments began soon after the first attachment had been formed, with most babies having several attachments by 10 months old, including mothers, fathers, siblings, and extended family
Schaffer studied 60 babies from a working-class area of Glasgow in a longitudinal study over the period of a year and again at 18 months, both through self-report and observation in their own homes
The first specific attachment was formed by 50% of infants around 7 months old, evidenced by separation anxiety towards a particular adult, often the mother
Attachment tends to be to the caregiver who is most interactive and sensitive to infants' signals (reciprocity), not necessarily the person they spend the most time with