The Strange Situation is a test created by Mary Ainsworth to explore childhood attachments patterns. The procedure begins with the child and his mother in a room where the child is allowed to play and explore alone. A stranger enters the room, talks to the mother, and approaches the child while the mother leaves the room.
After a short period, the mother comes back and reunites with the child. The mother and the stranger leaves, and the child is left to play alone. The stranger then comes back and attempts to interact with the child. The mother returns for a second reunion as the stranger leaves.
Throughout the procedure, the child is observed on four aspects: play behavior, reactions to departure and to the mother's return, and behavior when the stranger is around. Ainsworth categorized the nature of the children's attachment into three groups based on their behaviors.
A child is said to have a Secure Attachment when he is able to freely explore when the mother is around, interacts with the stranger when the mother is present but not when she is absent, shows distress when the mother leaves, and is happy to see the mother return.