Mary Ainsworth: Theory & Biography

Instructor: Gary Gilles

Gary has a Master's degree in Counseling Psychology and has been teaching and developing courses in higher education since 1988.

Mary Ainsworth is a pivotal figure in psychology. She invented one of the most widely used assessment tools for discovering a child's attachment style. Learn about her life and how she contributed to attachment theory, and test your knowledge with quiz questions.

Who Was Mary Ainsworth?

Mary Ainsworth was a Canadian developmental psychologist best known for her work in attachment theory. She created the classic study used in attachment research called 'The Strange Situation.'

Early Years

Mary Ainsworth, born Mary Salter in 1913, first became interested in psychology after reading William McDougall's book, Character and the Conduct of Life, when she was 15 years old. A year later, she enrolled at the University of Toronto in the honors psychology program. In addition to her bachelor's degree, she went on to earn both a master's and doctorate in psychology at the University of Toronto, where she also taught for several years after completing her academic training.

In 1950, Mary married Leonard Ainsworth and, shortly thereafter, moved with him to London so that he could finish his Ph.D. at the University College in London.

Introduction to Attachment Research

While Ainsworth was in London, she worked at the Tavistock Clinic where John Bowlby was the director. Bowlby is the researcher most commonly associated as the main pioneer for the establishment of attachment theory.

Ainsworth had the opportunity to work under Bowlby's guidance investigating how maternal separation affected a child's emotional and relational development. Bowlby and Ainsworth found that when a child does not have a stable, predictable and readily accessible mother figure or primary caregiver, the child experiences detrimental emotional and relational effects.

In 1954, Ainsworth left Tavistock Clinic to do her own attachment-related research in Kampala, Uganda. She conducted a longitudinal field study on mother-infant interaction to assess how the process of attachment occurs in a natural setting.

Ainsworth found that mother-infant interactions created different responses in children. For some, the interaction gave the child a sense of security. For others, it prompted conflict and problematic behavior. She discovered that the way children engaged with their mothers had much to do with how responsive the mothers were to their infants' needs. She eventually published her research results in a book entitled, Infancy in Uganda.

The Strange Situation

Ainsworth is best known for developing a research assessment tool called The Strange Situation. It was developed to help researchers better understand the different types of reactions infants and toddlers have to separations that occur with their mothers. Here's a brief summary of how The Strange Situation works:

A mother and her child (usually between 12-18 months of age) are taken to a small room where there are toys at one end and a chair at the other. The mother helps engage the child with the toys and then leaves the room. After a short period of time, the mother reenters the room and, if needed, consoles the child. This might happen several times throughout the experiment in various forms. At some point in the experiment, a stranger might enter the room in place of the absent mother.

While these comings and goings are taking place, researchers are watching the events taking place in the room through a one-way mirror. They are particularly interested in how the child responds to the mother's departure and reunion. For example, if the child is distressed at the mother's departure, this would be a sign that the child finds security in the mother's presence. In contrast, if the child was indifferent to the mother leaving the room, or actually felt comfortable in the presence of a stranger, this would be a sign that the child is already learning to depend less on the mother or doesn't expect his or her needs to be met by her.


As a result of these experiments, Ainsworth was able to categorize the various responses into three groups:

Secure Attachment

A securely attached child is most content when in the presence of his mother. The mother acts as a reference point for the child. So when the mother is absent, the child feels distressed. When the mother returns, the child feels comforted and secure again. The presence of a stranger without the mother would also be distressing for a child who is securely attached. A secure attachment is fostered when parents consistently meet a child's needs with attentive and nurturing responses.

Ambivalent Attachment

An ambivalently attached child is one that feels insecure in his relationship to the mother. The inconsistent responses he receives from the mother are the root of the insecurity. At times he receives a warm, nurturing response and at other times the response may be harsh or punitive. The child is uncertain (or ambivalent) about which response he will receive at any given time. In The Strange Situation, an ambivalent child might be difficult to console after the mother returns to the room because he fears she will leave again. The ambivalent child is typically fearful.

Avoidant Attachment

The child with an avoidant attachment tends to show little regard for the mother's absence in The Strange Situation and may even prefer the presence of the stranger over the mother. This emotional indifference shown by the child in The Strange Situation is often a sign that the child's ongoing needs at home go largely unmet or ignored.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account