Criticisms of Ainsworth’s Strange Situation Procedure
Ainsworth’s Strange Situation transformed developmental psychology, but critics argue that it is culturally narrow, artificially stressful, oversimplified and not always reliable outside the lab. Here is why those limits matter for how we assess and understand attachment.
Mary Ainsworth’s Strange Situation Procedure (SSP) is one of the most influential assessment tools in developmental psychology. Developed in the 1970s, it uses a structured laboratory setting in which infants experience brief separations and reunions with their caregiver. The goal is to evaluate how infants use the caregiver as a secure base and how they respond to stress. Ainsworth identified three main attachment classifications: secure, avoidant and resistant, with disorganised attachment being added later by Main and Solomon.
Although the Strange Situation has become the gold standard measure for attachment research, it has also attracted substantial criticism. Scholars have questioned its cultural validity, ecological validity, reliability, stressfulness and its narrow focus on behaviour within a single context.
This essay presents the major criticisms of the Strange Situation to provide a balanced and rigorous overview. The SSP made an enormous contribution to developmental science, but understanding its limitations helps us interpret attachment classification more thoughtfully and use it responsibly.
Cultural Bias and Limited Cross Cultural Validity
One of the most frequently highlighted criticisms of the Strange Situation is its cultural bias. Ainsworth’s research was based primarily on American middle class families whose caregiving practices emphasised independence and brief separations. The SSP assumes that short separations are normative and appropriate tests of attachment security.
However, this assumption does not hold across cultures.
For example:
In Japanese families, infants are rarely separated from their mothers during the first year. As a result, the Strange Situation often produces unusually high rates of resistant attachment, not because Japanese infants are insecure, but because the procedure is far more stressful for them than for American children.
In German families, where independence is encouraged earlier, infants may appear avoidant in the Strange Situation but may actually be securely attached within their cultural context.
These examples show how cultural norms shape infant responses. Critics argue that the Strange Situation is not a culturally neutral tool and that its classifications should not be uncritically applied across societies.
This cultural bias raises a deeper concern: the Strange Situation may rank certain caregiving styles as more or less secure based on Western values rather than universal developmental principles.
Low Ecological Validity
Another criticism is that the Strange Situation takes place in a highly controlled, unfamiliar laboratory environment. Critics argue that behaviour observed in this setting does not always reflect the richness of everyday attachment interactions.
Infants may behave differently:
in familiar spaces
with different caregivers
under natural stressors
during real world separations and reunions
A short, staged separation in a laboratory may capture only a narrow slice of an infant’s attachment system. Critics argue that attachment security is better understood through naturalistic observation, everyday routines and broader relational patterns.
Because the Strange Situation artificially induces stress, behaviour may reflect momentary distress rather than stable attachment style. This creates the risk of overinterpreting a single snapshot as a stable trait.
Stress Levels and Ethical Concerns
Some scholars argue that the Strange Situation places infants under unnecessary stress. The procedure is deliberately designed to elicit anxiety through separation from the caregiver and the presence of an unfamiliar adult.
While most infants recover quickly, critics point out that:
the stress may be significant for infants who rarely experience separation
ethical guidelines have become more cautious since the 1970s
repeated use in research raises cumulative ethical questions
Although the SSP is widely considered ethically acceptable, these concerns highlight how developmental research must continuously revisit its standards as cultural and ethical norms evolve.
Overly Narrow Attachment Classifications
Ainsworth’s original classifications included only secure, avoidant and resistant attachment. Later, Main and Solomon added disorganised attachment, which has since received enormous research attention.
Critics argue that even with four categories, the system is still overly simplistic. Human attachment is more dimensional and fluid than categorical labels suggest.
Some infants show behaviours that fall between categories. Others show different styles with different caregivers. Research also suggests that attachment can vary across contexts and developmental stages.
Treating attachment style as a fixed, singular classification may obscure important individual differences and relational dynamics.
Disorganised Attachment: Validity and Interpretation Issues
The addition of disorganised attachment has brought its own set of criticisms. Disorganised behaviours include contradictory, confused or disoriented responses during reunion.
Critics argue that:
the category is extremely broad, grouping together many different behaviours
it may pathologise infants under situational stress
its link with later psychopathology is often overstated
coders may interpret behaviours differently, reducing reliability
Because disorganisation is associated with trauma in some cases, there is also a risk that researchers or clinicians overinterpret normal variability as a sign of maltreatment. This raises ethical concerns about misclassification.
Reliability Concerns and Observer Bias
Scoring the Strange Situation requires extensive training, and even then, coders may differ in how they interpret nuances of infant behaviour.
Critics note that:
coding manuals are lengthy and somewhat subjective
small variations in behaviour can lead to different classifications
some labs achieve high reliability but others do not
cultural expectations may influence how coders judge behaviours
This reliance on skilled interpretation introduces the potential for bias and reduces consistency across studies.
Limited Consideration of Temperament
Another criticism is that Ainsworth focused heavily on caregiving sensitivity and did not sufficiently account for biological factors such as temperament.
Infants differ in:
fearfulness
irritability
adaptability
responsiveness to novelty
A highly fearful infant may appear resistant or disorganised in the Strange Situation even if their caregiver is sensitive and responsive.
Critics argue that attachment behaviour cannot be explained solely by caregiving quality; temperament interacts with caregiving in shaping infant responses. The Strange Situation may therefore conflate caregiving differences with innate temperament traits.
Attachment as a Relationship, Not a Trait
Attachment researchers emphasise that attachment is a relationship specific system. An infant may be securely attached to one caregiver and insecurely attached to another.
The Strange Situation usually examines only one relationship, typically with the mother. Critics argue that:
this does not capture the full network of attachment relationships
focusing exclusively on mothers reinforces outdated assumptions about caregiving
security with one caregiver may buffer insecurity with another
By examining only one attachment relationship, the SSP may give an incomplete or skewed picture of the infant’s broader attachment landscape.
Context Specificity and Situational Variability
Attachment behaviours may vary across contexts. A laboratory separation is just one possible context, and some infants may react differently to separations at home, to bedtime routines, to emotional stressors or to physical discomfort.
Critics argue that the Strange Situation assumes too much consistency across contexts and may misrepresent infants whose attachment behaviours are more situationally sensitive.
Simply Put
Ainsworth’s Strange Situation remains one of the most important and influential tools in attachment research. It provided a structured way to observe how infants seek comfort and security, and it opened the door to decades of developmental research.
But it is not without limits. Critics argue that the SSP is culturally biased, artificially stressful, overly simplistic and not always reliable across coders or contexts. It may conflate temperament with attachment and may not fully capture the relational complexity of infants who form multiple attachment bonds.
These criticisms do not invalidate the Strange Situation, but they remind us to interpret attachment classifications cautiously and contextually. Used thoughtfully and alongside other measures, the SSP can still provide valuable insight into early relationships and developmental pathways.
References
Bowlby, J. (1969). Attachment and Loss: Volume 1. Attachment. Basic Books.
Table of Contents
