Most research on attachment is based on

A) stranger anxiety.
B) the Strange Situation.
C) separation anxiety.
D) avoidant attachment.

The majority of research on attachment is based on the Strange Situation, which was developed by Mary Ainsworth in the 1970s. This laboratory procedure involves a series of separations and reunions between the infant and caregiver, allowing researchers to observe patterns of attachment behavior and classify infants as securely attached, insecurely attached (avoidant or ambivalent/resistant), or disorganized/disoriented.