Mary Ainsworth was a Canadian developmental psychologist who conducted research in the field of attachment theory and developed the Strange Situation Test. 

Early Life

Ainsworth was born in Glendale, Ohio and raised in Canada as the oldest of four girls. Both her father and mother were Dickinson College graduates and placed significant emphasis on proper education. Ainsworth graduated from high school eager to pursue a degree in psychology and enrolled in the University of Toronto in 1929. There she earned her bachelor’s, master's, and her PhD, and she began teaching at the university in 1938. In 1942, Ainsworth enlisted in the Canadian Women’s Army Corp where she rose to the rank of major within the Corps.

Professional Life

In 1946, Ainsworth returned to teaching in Toronto. Shortly after her marriage in 1950, she moved to London with her husband Leonard Ainsworth, so that he could pursue his degree from University College London.

During her time in England, Ainsworth was invited to participate in research at Tavistock Clinic, where she worked with John Bowlby. The research focused on examining what effects interference in the mother and child bond may have on the development of the child. The findings revealed that when a bond between mother and child is broken, the child is at risk for developmental challenges. Ainsworth later traveled to Kampala, Uganda where she worked at the East African Institute for Social Research, continuing her exploration into the significance of the mother-child bond.

Ainsworth taught at John Hopkins University from 1959 until 1975, when she accepted a position as professor of psychology at the University of Virginia. She remained at the University of Virginia until her retirement in 1984. Ainsworth and her husband divorced in 1960.

Find a Therapist

Advanced Search

Contribution to Psychology

Ainsworth, in collaboration with colleague Sylvia Bell, developed a technique called the Strange Situation Test. This test is used to examine the pattern of attachment between a child and the mother or caregiver. This method of measuring the child’s specific attachment characteristics is highly respected and well established, and variations of the procedure are used throughout the clinical world of psychiatry and psychology today.

The Strange Situation Test is characterized by an observation phase and an assessment phase. During the observation phase, the clinician places both the mother (or caregiver) and child in a secure environment and allows them to interact to the point of familiarity with their surroundings. A stranger is introduced into the environment and interacts with the child, and then the parent leaves the room. When the parent returns, the child and parent are reunited and the stranger exits. After this point, the parent exits, leaving the child alone. During that time, the stranger enters again, interacts with the child, and the parent returns. The stranger leaves again and the parent and child are left alone to interact.

The child’s behavior is examined and assessed throughout this exercise. There are four key elements of behavior that are examined with respect to the child:

  1. How much does the child explore his or her surroundings?
  2. What is the child’s reaction when the parent leaves? 
  3. Does the child express any anxiety with the introduction of the stranger when the child is alone?
  4. Assess the behavior of the child when interacting with the parent.

The results of this experiment have been categorized into four specific types of attachment:

  1. Secure Attachment: Secure attachment is a healthy, strong attachment to the mother. This child will explore and engage with others when the mother is present, however, when the mother leaves, this child will become agitated. If alone with the stranger, the child will avoid contact with the stranger.
  2. Anxious-Resistant Insecure Attachment: This child displays elevated anxiety when the stranger is introduced to the environment, even while the mother is there. The child will not freely explore the surroundings and becomes extremely agitated and distressed when the mother exits. When the mother re-enters the environment, the child appears resentful and unreceptive to the mother’s attempts at interaction. Often this child will try to move away from the mother when she returns. An anxious-resistant attachment style is associated with a child whose needs are not reliably met by the parent. Parents may prioritize their own needs over the child's or only periodically respond to the child's need for love, comfort, or affection. An anxious-resistant attachment style is frequently the product of inadequate parenting and strongly correlates with future attachment problems. 
  3. Anxious-Avoidant Insecure Attachment: This child will display ambivalence when the mother is present or not present. This child rarely clings to the caregiver and often refuses to be held. The child will avoid exploration and displays similar ambivalence toward strangers when they enter the environment. Children with an avoidant attachment style have learned that their efforts to get their needs met are ignored. Strangers may be treated virtually the same as the parent, with the child showing little preference regarding caregivers. While an anxious-avoidant attachment style is maladaptive, it is less strongly correlated with subsequent attachment problems than is an anxious-resistant attachment style. 
  4. Disorganized/Disoriented Attachment: A child that falls into this category may appear distressed when the mother exits and show immediate relief upon her return. However, the child may not want to be held or may exhibit anger once the mother approaches. This child may also exhibit repetitive behaviors, such as hitting or rocking. Further research revealed that more than half of the mothers with a child who fell into this category had suffered a trauma immediately before the birth of the child and had developed depression as a result of that trauma.

Ainsworth's Strange Situation test demonstrated that, for young children, the primary caregiver serves as a secure base from which to explore the world. Children with secure attachments are upset when their caregivers leave, but comforted by their presence in stressful situations. Children with insecure attachments, however, are much less comforted by their parents and do not have the “secure base” that securely attached children have. The results of Ainsworth's research challenged traditional notions regarding the mother-child bond and demonstrated that infants who are fed on demand and comforted when crying, rather than adhering to a particular routine, tend to develop secure attachments to their mothers.

Subsequent research has demonstrated a strong correlation between a child's attachment style and mental health difficulties. People tend to use their childhood attachment styles in adult relationships, including with children and romantic interests, so insecure attachments could potentially be passed from generation to generation, with an insecurely attached mother producing an insecurely attached child. 

Ainsworth was a member of the:

  • Society for Research in Child Development
  • Association for Child Psychology and Psychiatry
  • American Psychological Association
  • British Psychological Society
  • American Association for the Advancement of Science
  • Eastern Psychological Association

She received several awards, including the Distinguished Contribution Award from the Maryland Psychological Association in 1973 and the Gold Medal for Scientific Contributions from the American Psychological Foundation in 1998.

Controversies and Criticism

Ainsworth's Strange Situation test was designed to be used with mothers and their children, so her research reveals much less about attachments between fathers and children. Some researchers have also emphasized that Ainsworth's research may not apply across cultures. A brief separation from a caregiver might mean something very different in a small tribal culture or in a family where a child is regularly left with various caregivers or frequently around new people. There is also some concern about whether one brief separation can be used to measure continuity of attachment. A child or mother might be having a bad day, for example, and this could alter their usual pattern of relating. 

This page contains at least one affiliate link for the Amazon Services LLC Associates Program, which means receives financial compensation if you make a purchase using an Amazon link.

Books by Mary Ainsworth

Quote by Mary Ainsworth

Quote on hatred by Mary Ainsworth