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Ainsworth: the Strange Situation, attachment types and caregiver sensitivity

Edexcel IAL Psychology · WPS03 Applications of Psychology

Ainsworth gave psychology a standard way to measure attachment, three attachment types and an explanation of why they differ (spec 5.1.2).

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The Strange Situation procedure

Designed by Ainsworth and Wittig (1969). A controlled observation in a laboratory playroom, about 20 minutes, in eight episodes (most about three minutes):

1. Mother, infant and experimenter enter. 2. Mother and infant alone; infant explores. 3. Stranger enters, talks to mother, approaches infant. 4. Mother leaves; stranger stays. 5. Mother returns; stranger leaves. 6. Mother leaves; infant alone. 7. Stranger returns. 8. Mother returns.

Measured: separation anxiety, stranger anxiety, reunion behaviour, exploration and use of the mother as a secure base. Observers behind a one-way mirror counted exploration and crying in 15-second intervals and rated behaviour towards the mother (proximity seeking, contact maintaining, avoidance and resistance) on 7-point scales (Ainsworth et al., 1971).

Attachment types

Type	Exploration	Separation	Stranger	Reunion	% in Ainsworth et al. (1978)
B: secure	Explores, uses mother as secure base	Some distress	Wary but friendly with mother present	Seeks comfort, quickly calmed	67%
A: insecure-avoidant	Explores, ignores mother	Little distress	Little concern	Avoids or ignores mother	21%
C: insecure-resistant (ambivalent)	Explores little	Very distressed	Very wary	Seeks and resists contact, hard to comfort	12%

Ainsworth's types. Percentages computed from Ainsworth et al.'s (1978) sample of 105 (22 A, 70 B, 13 C), as listed in Pearson's WPS03 summary of studies. Main and Solomon (1990) later added D: disorganised.

Caregiver sensitivity

Ainsworth (1978) proposed the caregiver sensitivity hypothesis: attachment type depends on how the mother responds to the infant.

Sensitive, prompt, consistent responses lead to secure attachment.
Rejecting or ignoring the infant leads to avoidant attachment.
Inconsistent responses lead to resistant attachment.

Ainsworth's earlier field work in Uganda (26 Ganda families, 1954 to 1955) and the Baltimore home observations (26 families) informed the idea. Later research (De Wolff and van IJzendoorn, 1997) found only a weak correlation (about 0.24) between sensitivity and attachment, so sensitivity is not the whole story.

Evaluation

Reliability: standardised episodes and coding scales give high inter-rater reliability; Wartner et al. (1994) found that 82% of 40 children in Regensburg, Germany, had the same attachment classification (A, B, C or D) in infancy and at age 6.
Validity: an unfamiliar laboratory may not show everyday behaviour (low ecological validity); it may measure attachment to one caregiver only.
Culture bias: the types and the 'secure is best' assumption come from middle-class American families; Japanese infants rarely separated from mothers may look resistant (Takahashi), and German infants raised for independence may look avoidant (Grossmann).
Temperament (Kagan) offers an alternative: infants' innate temperament, not maternal sensitivity, may shape behaviour.
Ethics: infants are deliberately mildly distressed; episodes are cut short if distress is severe and parents can stop the procedure.

Worked example

An infant explores when her mother is present, cries when she leaves, and is quickly comforted on reunion. Classify her and explain using caregiver sensitivity.

Exploring with mother present and seeking comfort on reunion fit **type B, secure**.
Ainsworth would predict her mother responds sensitively and consistently to her signals.
So she trusts the mother as a secure base.

Answer: Secure (type B), predicted by a sensitive, responsive caregiver.

Key idea: Strange Situation: 8 episodes, about 20 minutes, measures separation and stranger anxiety, reunion and secure base. Types (Ainsworth et al., 1978): B secure 67%, A avoidant 21%, C resistant 12% (plus D disorganised). Caregiver sensitivity: sensitive gives secure, rejecting gives avoidant, inconsistent gives resistant.

Check yourself

Which behaviour best distinguishes an avoidant infant in the Strange Situation?
- Ignores or avoids the mother on reunion
- Is quickly comforted on reunion
- Seeks and then resists contact on reunion
- Refuses to explore at all
Show answer
Ignores or avoids the mother on reunion. Avoidant infants show little reaction to separation and avoid the mother when she returns.
An infant is very distressed when the mother leaves and on her return clings to her but also pushes her away. This is
- type A, insecure-avoidant
- type B, secure
- type C, insecure-resistant
- the stranger anxiety episode
Show answer
type C, insecure-resistant. Seeking and resisting contact marks resistant (ambivalent) attachment.
How many episodes are there in the Strange Situation?
Show answer
8. Eight episodes of about three minutes.
According to the caregiver sensitivity hypothesis, inconsistent responses from a mother lead to
- secure attachment
- insecure-avoidant attachment
- monotropy
- insecure-resistant attachment
Show answer
insecure-resistant attachment. Inconsistency leaves the infant unsure, so it clings and resists.
De Wolff and van IJzendoorn (1997) found a correlation of about 0.24 between sensitivity and attachment. What does this suggest?
- Sensitivity fully explains attachment type
- Sensitivity is linked to attachment but only weakly, so other factors also matter
- Sensitivity is unrelated to attachment
- Insensitive mothers have secure infants
Show answer
Sensitivity is linked to attachment but only weakly, so other factors also matter. A weak positive correlation.
Which is a validity criticism of the Strange Situation?
- It uses eight episodes
- Observers use a one-way mirror
- Exploration is counted in 15-second intervals
- It takes place in an unfamiliar laboratory, so behaviour may not reflect everyday attachment
Show answer
It takes place in an unfamiliar laboratory, so behaviour may not reflect everyday attachment. Low ecological validity.
Explain one ethical issue with the Strange Situation and how it is managed.
Show answer
Infants are deliberately caused mild distress by separation from the mother and a stranger; this is managed by stopping or shortening episodes if the infant becomes very distressed and letting the parent stop the procedure.. Name the harm and the safeguard.

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Last updated 8 November 2026. Spotted a mistake? Tell us.