Attachment theory was put forward by Bowlby (1969) and adapted by Ainsworth & Bell (1970). Ainsworth devised the Strange Situation Classification (SSC) to investigate how attachment might differ between children: the experiment is set up so behaviour of the infant can be observed secretly in relation to the mother, stranger, and on its own. It puts children into three categories:
Securely attached: children feel confident that their attachment figure (AF; either mother or stranger) will be available care for them. They use the AF as a safe point of reference and comfort in times of distress; suggesting the caregiver is sensitive to infant’s needs and signals
Insecure avoidant: children do not turn to their AF while exploring (physically or emotionally). The AF is not someone they turn to when distressed, suggesting the caregiver may be insensitive to infant’s needs and signals, or simply unavailable.
Insecure resistant: children are indifferent to AF. They can show clingy and dependent behaviour, while also rejecting the AF when engaging in interactions. Feelings of security don’t easily develop, making it difficult for the child to explore the environment, and difficult to sooth when upset. Thus suggesting inconsistent responses to needs of the child by the primary caregiver.