Mary Ainsworth: the woman who saw attachment styles before anyone else

Who is Mary Ainsworth?

Mary Salter was born in Ohio in 1913 and grew up in Toronto, where she did all of her schooling. Her dissertation, defended in 1939, was already about security. In it she developed an idea she had learned from her advisor, William Blatz: a child needs a secure base in order to dare to explore. In the early 1950s she followed her husband to London and answered a job ad: John Bowlby was looking for someone to analyze observations of children separated from their parents. She joined his team at the Tavistock Clinic. That meeting shaped the rest of her life.

In 1954 came another move, this time to Uganda. There she ran the first field study of attachment: 26 families near Kampala, visited every two weeks for nine months, with an interpreter. She noticed that babies differ in how they use their mother as a starting point for exploring. Back in the United States, at Johns Hopkins University in Baltimore, she launched an even more intensive study in 1963: 26 families observed at home throughout the child’s first year, then, at twelve months, a session in a laboratory playroom. That session is called the Strange Situation. In 1975 she joined the University of Virginia, where she finished her career. She died in 1999.

Why does a specialist in babies matter for your relationship? Because she gave attachment theory its method and its vocabulary. Without her, Bowlby might have remained a beautiful idea. And because her main discovery holds at any age: what builds security isn’t being there all the time, it’s responding well when the other person calls out.

The central idea

All babies become attached, even to a parent who mistreats them: the system is too vital not to work. But they don’t all become attached in the same way. Ainsworth shows that children organize themselves around how available their attachment figure really is, and that this organization takes a few typical forms. You can recognize them by watching how the child reacts to a brief separation and, above all, to the reunion. These forms aren’t personality traits. They are the best strategy the child has found for keeping the bond with that particular parent.

Key concepts

The Strange Situation

An unfamiliar room with toys, a parent, a stranger, and eight episodes of about three minutes each: the parent and child explore, the stranger comes in, the parent leaves, comes back, leaves again and this time the child is alone, the stranger returns, and then the parent. The whole thing lasts about twenty minutes and is watched by observers. The brilliance of the setup is in what it looks at: not how much the child cries during the separation, but how the child welcomes the return. Does the child go to the parent? Let themselves be comforted? Go back to playing?

The three styles, then the fourth

Ainsworth describes three patterns. The secure child (group B) seeks contact at the reunion, calms down and goes back to exploring. The avoidant child (group A) ignores the parent or turns away, as if nothing had happened. Later measurements showed that these children are in fact stressed inside. The anxious-ambivalent child (group C) clings and fights at the same time, can’t be soothed and doesn’t go back to playing. In 1990, Mary Main and Judith Solomon added the disorganized pattern (group D): contradictory or frozen behaviors, a child who approaches with head turned away, who freezes, who seems afraid of the very person who should be reassuring. These are the direct ancestors of the four adult styles: Secure, Avoidant, Anxious, Disorganized.

Sensitivity to signals

The least known and most important part of her work happened at home, not in the lab. For a year, Ainsworth and her team noted how mothers responded to their baby’s signals. From this she built rating scales, the main one being sensitivity: noticing the signal, interpreting it correctly, and responding promptly and appropriately. The babies classified as secure at twelve months were those whose mothers had been the most sensitive over the year. Not the most present, not the most affectionate on the surface: the most accurate in their responses. Applied to couples, this is exactly what research now calls responsiveness.

The secure base and the safe haven

It was in Uganda that Ainsworth coined the expression that would become the title of Bowlby’s last book: the secure base. She observed that babies move away from their mother to explore, come back to her as soon as something worries them, then head off again. Two functions of the same bond: the safe haven, where you return when things go badly, and the base, where you set out from when things go better. In a 1989 article titled “Attachments beyond infancy,” she explicitly extends these functions to adult bonds, including the couple.

What the research says

The Baltimore study is tiny in size and immense in intensity: dozens of hours of home observation per family, something no study has repeated on that scale. But its reach comes mostly from what followed: the Strange Situation has been used in thousands of studies around the world.

• Baltimore. Of the 26 children, about two thirds are classified as secure, and the rest are split between avoidant and ambivalent. And the maternal sensitivity observed at home during the year predicts the classification at twelve months.
• The 1970 article. With Silvia Bell, Ainsworth publishes the Strange Situation on 56 one-year-olds: the mother’s presence encourages exploration, her absence slows it and triggers attachment behaviors, and the return concentrates the proximity-seeking gestures.
• The 1988 meta-analysis. Across 32 samples in 8 countries, nearly 2,000 children in all, the secure style is the majority everywhere (between 50 and 75%), and differences between samples within the same country are larger than differences between countries.
• Sensitivity and security. A 1997 meta-analysis confirms the link between parental sensitivity and the child’s security, but finds it more modest than Ainsworth did, with a correlation of about 0.24: sensitivity matters, but it doesn’t explain everything.
• From baby to adult. Cohorts followed into adulthood find a real but moderate continuity between classification at age one and adult attachment, with many trajectories that change, in both directions.

Limits and criticisms

The first limit is the sample: 26 white, middle-class families from Baltimore. The Strange Situation rests on an assumption, that separation creates moderate stress in the child, and that assumption depends on culture. In Japan, where babies are rarely separated from their mothers, the procedure causes extreme distress and over-classifies children as ambivalent. In northern Germany, where early independence is encouraged, it over-classifies them as avoidant. What the procedure measures is real, but the cutoffs don’t travel without caution.

The second criticism is about cause. Temperament researchers, including Jerome Kagan, argued that a child’s innate reactivity explains part of what Ainsworth attributed to the mother. Research has settled somewhere in the middle: parental sensitivity is a real but modest predictor of security, temperament plays a part, and so do fathers and other figures. This rules out a reading that Ainsworth never made but that popular accounts spread: holding the mother responsible for everything.

Finally, the Strange Situation is a tool for babies. In adults, attachment is measured differently: by interview, or by questionnaire such as the ECR-R scale. But these tools overlap little with one another, and a child’s classification at age one predicts their adult style only moderately. So Ainsworth’s styles are a starting point, not a prophecy. The past weighs, but it doesn’t lock you in.

How MyLoveLab uses her work

The four styles in the MyLoveLab test and in the Attachment and security dimension carry Ainsworth’s vocabulary, adapted to adults: secure, anxious, avoidant, disorganized, read along two axes rather than in boxes. Her lesson on sensitivity shapes level 5 of the program, where security is built through responses that are accessible, accurate and reliable, not through constant presence. Her method inspires level 3: a style is read from repeated reunions, never from a single gesture. And her secure base gives its name to level 10, becoming a base for the other person. To follow the story further, read the page on Cindy Hazan and Phillip Shaver, who brought these styles into the couple, or the article on the four attachment styles.

Further reading

• Infancy in Uganda: Infant Care and the Growth of Love · Book, 1967The first field study of attachment, where the idea of the secure base was born.
• Attachment, exploration, and separation: Illustrated by the behavior of one-year-olds in a strange situation · Article, 1970With Silvia Bell: the first detailed presentation of the Strange Situation.
• Patterns of Attachment: A Psychological Study of the Strange Situation · Book, 1978With Blehar, Waters and Wall: the landmark book, where the three styles are described and tied to the home observations.
• Attachments beyond infancy · Article, 1989The article where Ainsworth explicitly extends attachment to adult bonds, including the couple.

Frequently asked questions

References

1. Ainsworth, M. D. S. (1967). Infancy in Uganda: Infant Care and the Growth of Love. Johns Hopkins University Press.
2. Ainsworth, M. D. S. & Bell, S. M. (1970). Attachment, exploration, and separation: Illustrated by the behavior of one-year-olds in a strange situation. Child Development, 41(1), 49-67.
3. Ainsworth, M. D. S., Blehar, M. C., Waters, E. & Wall, S. (1978). Patterns of Attachment. Erlbaum.
4. Ainsworth, M. D. S. (1989). Attachments beyond infancy. American Psychologist, 44(4), 709-716.
5. Main, M. & Solomon, J. (1990). Procedures for identifying infants as disorganized/disoriented during the Ainsworth Strange Situation. In M. T. Greenberg, D. Cicchetti & E. M. Cummings (dir.), Attachment in the Preschool Years (p. 121-160). University of Chicago Press.
6. van IJzendoorn, M. H. & Kroonenberg, P. M. (1988). Cross-cultural patterns of attachment: A meta-analysis of the Strange Situation. Child Development, 59(1), 147-156.
7. De Wolff, M. S. & van IJzendoorn, M. H. (1997). Sensitivity and attachment: A meta-analysis on parental antecedents of infant attachment. Child Development, 68(4), 571-591.
8. Bretherton, I. (1992). The origins of attachment theory: John Bowlby and Mary Ainsworth. Developmental Psychology, 28(5), 759-775.

See the full bibliography