Mary Main and Her Contributions to Attachment Theory

When we say “attachment theory” your mind may immediately dart to John Bowlby or Mary Ainsworth. But what about the lesser-known Mary Main?

Mary Main was an American psychologist and professor at the University of Berkeley. She studied attachment theory through the late 1900s, with the help of her colleagues Judith Solomon, Nancy Kaplan, and Carol George.

Main was Ainsworth’s protégé, in a way, learning from her and replicating her research. However, Main noticed something Ainsworth didn’t, and this led to the development of the fourth attachment style: disorganized attachment.

But how else did Main contribute to attachment theory? And what is our perspective on her work today? To answer all of your questions on Mary Main and her contributions to attachment theory, this article will cover:

• A brief biography and background of Mary Main
• Mary Main’s attachment styles
• Main and Solomon’s 1986 research on attachment theory
• Mary Main Adult Attachment Interview (AAI)
• Today’s perspective on Main’s work

Brief Biography and Background of Mary Main

Mary Main was an American psychologist and professor at the University of California Berkeley. She was first interested in linguistics but then changed direction, focusing instead on researching adults.

While studying for her doctorate, Main was supervised by Mary Ainsworth, an expert in attachment theory who developed the first three attachment styles: secure, anxious-avoidant, and anxious-resistant. During this time, Main carried out a longitudinal study of infants and their mothers and fathers, now known as the Berkeley Social Development Study.

Main was inspired by Ainsworth’s Strange Situation Procedure, which involved conducting behavioral experiments with mothers, their infants, an observer, and a stranger. It went like this:

1. The observer introduces a mother and her baby to the experimental room and then leaves the room.
2. The baby explores the experimental room, and the mother does not engage.
3. A stranger enters the room. For the first minute, they’re silent. In the second minute, the stranger talks to the mother. And in the third, the stranger approaches the baby. After the 3 minutes are up, the mother leaves the room.
4. This is known as the first separation episode. The baby and the stranger are alone together for 3 minutes, and the stranger tries to interact with the baby.
5. The mother comes back into the room and greets and comforts her baby. She then leaves again with the stranger.
6. This is the second separation episode. The baby is left on their own.
7. The stranger enters the room and tries to interact with the baby.
8. The mother reenters the room, greets her baby, and the stranger leaves.

Main, like in Ainsworth’s research, studied how the infants behaved at each stage, and analyzed these behaviors to identify the infant’s attachment style. Main replicated a lot of Ainsworth’s findings. However, she noticed something that Ainsworth didn’t – more on this next.

Mary Main Attachment Styles

While studying and replicating Ainsworth’s research, Main found that the infants’ behaviors didn’t always fit Ainsworth’s original attachment style classification system. So, Main recorded any behaviors that seemed “odd.” For example, when an infant:

• Flapped their hands
• Repeated others’ speech or noises (called “echolalia”)
• Showed unusual or inappropriate emotions

Main noticed that roughly 10% of the infants showed odd behaviors. Previously, Ainsworth had marked these children down as “difficult to classify” and then placed them in category A (anxious-avoidant) or C (anxious-resistant). So, Main took her findings to Ainsworth and Ainsworth labeled these children as “insecurely attached” and suggested Main put them into a best-fit category.

But Main wasn’t satisfied with this. She didn’t think that she should put the infants in a category that they didn’t belong in. So, she continued to test the validity of Ainsworth’s system with a fellow researcher, Judith Solomon. In 1968, they came up with a new infant attachment classification: disorganized/disoriented, or D category.

Main and Solomon Attachment Theory 1986

Main and Solomon found that children displayed disorganized attachment most strongly during the reunion episodes of The Strange Situation. Let’s consider how the anxious-resistant and anxious-avoidant children reacted in these episodes to get an idea of how the disorganized attachers differed:

• Children who were anxious-resistant wanted to be close to their mother as soon as she returned
• Anxious-avoidant children would ignore their mother upon her return.

In contrast, children fitting into the disorganized category didn’t seem to know how to react. They seemed conflicted. Sometimes, they would approach their mothers, but other times, they would move away from them as if trying to get away from them. They also often looked afraid of their mothers and showed worrying behaviors, such as jerky movements, dissociation, and freezing.

Main and Solomon suggested that children develop a disorganized attachment if they find their parents frightening. This idea has been supported by research since, and it is still widely believed now. In fact, recent statistics show that around 48% of infants in the D category have experienced some form of neglect or abuse.

You might think that these findings would quench Main’s thirst for knowledge about attachment styles. But alas, she didn’t stop there.

Mary Main Adult Attachment Interview

Main continued to study attachment styles in the late 1900s. In the early 1980s, Main and her graduate students Nancy Kaplan and Carol George developed the Adult Attachment Interview (AAI) as part of the Berkeley Social Development Study.

For this study, they invited families to participate in the Strange Situation twice: with their mother when the infants were 12 months old and with their father when they were 18 months old. Then, they invited some of the families back again in 1982 when the children were 6 to do further assessments. This included the Mary Main attachment test, also known as the Adult Attachment Interview. This was a semi-structured interview, meaning it had a typical question/answer format, but all of the questions were open-ended, meaning they required more than yes/no answers.

Examples of the questions within the AAI include:

• Describe the relationship with your parents as a young child
• Choose five adjectives to describe the relationship with your mother/father
• Did you ever feel rejected as a child?

They made a system to understand the parents’ responses from the AAI called the “guess and uncover.” The researchers conducted the parent interview and then guessed what the babies may act like in situations based on what was said. They then compared the children’s behaviors and the parents’ responses and identified whether their guesses were right or wrong. They did this repeatedly until they had the AAI that many mental health professionals use today.

To find out more about the AAI, check out our article: Adult Attachment Interview (AAI): History, Applications and Impact.

Today’s Perspective on Main’s Work

Mary Main sadly passed away in January 2023. However, she continues to live on in her incredible contributions to attachment theory. The disorganized attachment style that she developed, along with Judith Solomon, is still widely supported. It helps inform our understanding of children who don’t show typical secure or insecure patterns of attachment behavior.

Main was one of the first to suggest that attachment patterns are transferred from parents to their children in her research with the AAI, and this concept is still relevant today. Many mental health professionals worldwide use the AAI to link parents’ attachment styles to their children’s attachment behaviors. This information then informs the treatment approach they use, which in turn helps give the children the best possible chance of developing attachment security.