Mary Ainsworth

The laboratory procedure uses a sequence of brief separations and reunions involving an infant, a caregiver, and an unfamiliar adult. Researchers pay particular attention to how the infant uses the caregiver as a secure base and responds when the caregiver returns.

Ainsworth's research distinguished secure, anxious-avoidant, and anxious-ambivalent or resistant patterns. A disorganized category was added later by researchers including Mary Main and Judith Solomon.

Her observations of mothers and infants in Uganda helped her examine secure-base behavior in everyday life before the Strange Situation was developed. That work appeared in Infancy in Uganda and complemented John Bowlby's broader attachment theory.

Yes. She joined Bowlby's research group at the Tavistock Clinic in London during the 1950s. Her observational methods supplied important empirical support for ideas that Bowlby had been developing about attachment and separation.