Strange Situation Experiment

“Laurel Tree House childcare centre” by Greens MPs is licensed under CC BY-NC-ND 2.0

The Strange Situation experiment, developed by Mary Ainsworth in the late 1960s, revolutionized the study of attachment and laid the foundation for a systematic, observational method to assess the quality of infant-caregiver attachment.

The experiment involves observing a child’s response to a brief separation from, and reunion with, their primary caregiver, as well as the child’s reactions to a stranger, under controlled conditions (Ainsworth, 1969; Ainsworth et al., 1978). From these observations, Ainsworth classified attachment into three main types: secure, anxious-ambivalent, and anxious-avoidant. Later, with Mary Main’s extension, a fourth category, disorganized attachment, was added (Main & Solomon, 1990).

Historical Background

Prior to Ainsworth’s work, John Bowlby’s attachment theory provided the conceptual framework, but there was no standardized method for empirically measuring attachment styles (Bowlby, 1969; Ainsworth, 1969). Ainsworth’s work in Uganda and Baltimore, combined with her collaboration with Bowlby, led to the creation of the Strange Situation Procedure (SSP). The SSP provided a reliable, replicable way to observe and classify attachment behaviours in infants aged 9 to 18 months (Ainsworth, 1969; Ainsworth et al., 1978).

Impact on Psychology

The SSP demonstrated that early caregiving experiences are predictive of children’s social and emotional development (Ainsworth, 1969; Ainsworth et al., 1978). Secure attachment is linked to better social competence, lower rates of externalizing and internalizing behaviours, and higher academic achievement (Groh et al., 2014; Fearon et al., 2010). The SSP also influenced the development of clinical interventions focused on promoting secure attachment, such as attachment-based therapy and parenting programs (Madigan et al., 2013).

Influence on Social Sciences

Beyond psychology, the SSP had a profound impact on social work, education, and child welfare policies. The recognition that attachment security is a key factor in child development has led to the prioritization of early relational interventions in schools, adoption agencies, and social care services (Ainsworth et al., 1978; Madigan et al., 2013). The SSP’s emphasis on observational, non-verbal measures of child well-being has also influenced research in sociology and anthropology, particularly in the study of child-rearing practices across cultures (Ainsworth, 1969; Ainsworth et al., 1978).

Criticisms and Ethical Considerations

The SSP has faced criticism for its potential to cause distress to children and for its reliance on middle-class, Western samples (Ainsworth et al., 1978; Main & Solomon, 1990). However, the SSP remains one of the most influential tools in developmental psychology, and its principles continue to shape our understanding of early childhood experiences and their long-term effects.

References

Ainsworth, M. D. S. (1969) Object relations, dependency, and attachment: A theoretical review of the infant-mother relationship. Child Development, 40(4), 969–1025.

Ainsworth, M. D. S., Blehar, M. C., Waters, E., & Wall, S. (1978) Patterns of attachment: A psychological study of the strange situation. Hillsdale, NJ: Lawrence Erlbaum Associates.

Bowlby, J. (1969) Attachment and loss: Vol. 1. Attachment. New York: Basic Books.

Fearon, R. M. P., Bakermans-Kranenburg, M. J., van IJzendoorn, M. H., Lapsley, A. M., & Roisman, G. I. (2010) The significance of insecure attachment and disorganization in the development of children’s externalizing behavior: A meta-analytic study. Child Development, 81(2), 435–456.

Groh, A. M., Roisman, G. I., van IJzendoorn, M. H., Bakermans-Kranenburg, M. J., & Fearon, R. M. P. (2014) The significance of security of attachment for children’s social competence: A meta-analysis. Child Development, 85(2), 615–632.

Main, M., & Solomon, J. (1990) Procedures for identifying infants as disorganized/disoriented during the Ainsworth Strange Situation. In M. Greenberg, D. Cicchetti, & E. Cummings (Eds.), Attachment in the preschool years (pp. 121–160). University of Chicago Press.

Madigan, S., Atkinson, L., Laurin, K., & Benoit, D. (2013) Attachment security to mother and father in middle childhood: Relations to self-esteem, adjustment, and achievement in grade 6. Developmental Psychology, 49(1), 1–10.