When two people develop long and lasting emotional bonds, in this case the infant and their caregiver. Both the infant and caregiver seek closeness to each other and feel secure when close to their attachment figure.
Schaffer found that for 65% of infants, the mother was the sole primary attachment figure, 30% had both parents, and only 3% had the father as the primary attachment figure.
Initially less important than the mother's, but by 18 months most infants had developed attachment to the father. Fathers provide more active play to encourage risk-taking, while primary caregiver fathers show more sensitive responsiveness like mothers.
Babies just really need to be fed, and they love their mother because she is the best way to get food, parents' love for infants is more relief that the baby has stopped crying
Crying behavior is positively reinforced by parents providing care, and parents' behavior is negatively reinforced by the removal of the unpleasant crying stimulus
Infants are naturally driven to form a strong bond with their primary caregiver (usually the mother) due to evolutionary reasons, as the caregiver is the main source of food and protection
A set of schemas formed about relationships, based on the first attachment relationship, that guide beliefs about the trustworthiness of others and the normality of expressions of love