Ainsworth's strange situation

Mary Ainsworth took Bowlby's theory into the lab and built the single most-tested attachment paradigm on the NCE: the Strange Situation. If Bowlby explains why attachment exists, Ainsworth shows you how to measure it — and gives you four classifications examiners quiz relentlessly.

The Strange Situation is a ~20-minute structured lab procedure for infants roughly 12-18 months old, run as eight brief episodes of increasing stress. A caregiver and infant enter an unfamiliar playroom; a stranger enters; the caregiver leaves and returns twice. The key data are not whether the baby cries at separation, but how the baby uses the caregiver as a secure base for exploration and — most importantly — how the baby behaves at REUNION.

Ainsworth identified three patterns; a fourth was added later by Mary Main and Judith Solomon:

• Secure (Type B, ~60-65%): explores using caregiver as a base, may be distressed at separation, actively seeks and is comforted at reunion, then returns to play. Linked to sensitive, responsive caregiving.
• Insecure-Avoidant (Type A, ~20%): minimal distress at separation, ignores or avoids the caregiver at reunion, treats stranger and parent similarly. Linked to rejecting/unavailable caregiving.
• Insecure-Ambivalent/Resistant (Type C, ~10-15%): intensely distressed, clingy yet resistant at reunion (seeks contact but arches away, hard to soothe), too preoccupied to explore. Linked to inconsistent caregiving.
• Disorganized/Disoriented (Type D, Main & Solomon): contradictory, dazed, or fearful behavior — freezing, approaching then backing away. Associated with fright, abuse, or unresolved trauma in the caregiver.

Clinical Pearl: The behavior that classifies a baby is the REUNION, not the separation — secure infants seek comfort and settle, avoidant infants ignore the parent, ambivalent/resistant infants cling-but-can't-be-soothed, and disorganized infants show contradictory, fearful behavior (Main & Solomon's later addition).