December 1, 1913|
|Died||March 21, 1999
|Alma mater||University of Toronto|
|Era||20th century philosophy|
|Main interests||Attachment theory|
|Notable ideas||Finding of securely attached, insecurely attached - avoidant and ambivalent children, Strange situation|
Mary Dinsmore Salter Ainsworth (//; December 1, 1913 – March 21, 1999) was an American-Canadian developmental psychologist known for her work in early emotional attachment with the Strange situation design, as well as her work in the development of attachment theory.
Mary Ainsworth was born in Glendale, Ohio in 1913. She was the oldest of three daughters to Charles and Mary Salter. Her parents both graduated from Dickinson College. When Ainsworth was 5 years-old, her father was transferred to a manufacturing firm in Toronto, Canada where she spent the majority of childhood. Ainsworth was a clever child who thirsted for knowledge. She began reading by the age of three, and she became quite close with her father, who assumed the duties of tucking her in at night and singing to her. On the other hand, she did not have a warm relationship with her mother. While her parents always put a strong emphasis on education, it was William McDougall's book Character and the Conduct of Life that inspired her interest in psychology.
Ainsworth began classes at the University of Toronto at the age of 16 and decided to focus on psychology. She was one of only five students to be admitted into the honors course in psychology. Ainsworth completed coursework for her bachelor degree in 1935, and decided to continue her education at the University of Toronto with the intentions of earning her doctorate in psychology. She stayed to teach for a few years before joining the Canadian Women's Army Corps in 1942 in World War II, where she administered clinical evaluations and personnel assessment tests, reaching the rank of Major in 1945.
She returned to Toronto to continue teaching personality psychology and conduct research. She married Leonard Ainsworth in 1950 and moved to London with him to allow him to finish his Ph.D at University College London.
After many other academic positions, including a long tenure at Johns Hopkins University, she eventually settled at the University of Virginia in 1975, where she remained the rest of her academic career. Ainsworth received many honors, including the Award for Distinguished Contributions to Child Development in 1985 and the Distinguished Scientific Contribution Award from the American Psychological Association in 1989. She was elected a Fellow of the American Academy of Arts and Sciences in 1992.
During graduate school, Mary studied under the mentorship of William Emet Blatz, who was the founder and first director of the Institute of Child Study at the University of Toronto. Blatz focused on studying what he referred to as “security theory.” This theory outlined Blatz’s idea that different levels of dependence on parents meant different qualities of relationships with those parents, as well as, the quality of relationships with future partners. His tiers of dependence were labeled secure dependence, independent security, immature dependent security, and mature secure dependence. Blatz theorized that the more secure and mature that the interaction was between individuals, the more likely the relationship to be healthy and without insecurities. After leaving the Canadian Women's corps she returned to Toronto to continue teaching personality psychology and conduct research. She married Leonard Ainsworth in 1950 and moved to London with him to allow him to finish his graduate degree at University College. While in England, Ainsworth joined the research team of John Bowlby at the Tavistock Clinic, investigating the effects of maternal separation on child development. Comparison of disrupted mother-child bonds to normal mother-child relationship showed that a child's lack of a mother figure lead to "adverse development effects."
In 1954, she left the Tavistock Clinic to do research in Africa where she carried out her longitudinal field study of mother-infant interaction. Ainsworth's book from that field study, Infancy in Uganda remains an exceptional and classic ethological study in the development of Attachment, and demonstrates that the process reflects specific universal characteristics that cross linguistic, cultural and geographic lines.
In 1965, Ainsworth and Wittig designed the Strange Situation Procedure as a way of assessing individual differences in attachment behaviour. The Strange Situation Procedure is divided into eight episodes. In the first episode, the infant and his or her caregiver enter into a pleasant laboratory setting, with many toys. After one minute, a person unknown to the infant enters the room and slowly tries to make acquaintance. The caregiver leaves the child with the stranger for three minutes; and then returns. The caregiver departs for a second time, leaving the child alone for three minutes; it is then the stranger who enters, and offers to comfort the infant. Finally, the caregiver returns, and is instructed to pick up the child. As the episodes increase the stress of the infant by increments, the observer can watch the infant’s movement between behavioural systems: the interplay of exploration and attachment behaviour, in the presence and in the absence of the parent.
On the basis of their behaviors, the 26 children in Ainsworth's original Baltimore study were placed into one of three classifications. Each of these groups reflects a different kind of attachment relationship with the caregiver, and implies different forms of communication, emotion regulation, and ways of responding to perceived threats.
Secure attachment (B)
A child who's securely attached to its mother will explore freely while the caregiver is present, using her as a 'safe base' from which to explore. The child will engage with the stranger when the caregiver is present, and will be visibly upset when the caregiver departs but happy to see the caregiver on his or her return
Avoidant insecure attachment (A)
A child with the anxious-avoidant insecure attachment style will avoid or ignore the caregiver - showing little emotion when the caregiver departs or returns. The child will not explore very much regardless of who is there. There is not much emotional range regardless of who is in the room or if it is empty. Infants classified as anxious-avoidant (A) represented a puzzle in the early 1970s. They did not exhibit distress on separation, and either ignored the caregiver on their return (A1 subtype) or showed some tendency to approach together with some tendency to ignore or turn away from the caregiver (A2 subtype). Ainsworth and Bell (1970) theorised that the apparently unruffled behaviour of the avoidant infants is in fact as a mask for distress, a hypothesis later evidenced through studies of the heart-rate of avoidant infants.
Resistant insecure attachment (C)
Children classified as Anxious-Ambivalent/Resistant (C) showed distress even before separation, and were clingy and difficult to comfort on the caregiver’s return. They either showed signs of resentment in response to the absence (C1 subtype), or signs of helpless passivity (C2 subtype). In Ainsworth’s original sample, all six C infants showed so much distress in the course of the episodes of the Strange Situation Procedure ‘that observations had to be discontinued.’ 
A fourth category was added by Ainsworth's colleague Mary Main. In 1990, Ainsworth put in print her blessing for the new ‘D’ classification, though she urged that the addition be regarded as ‘open-ended, in the sense that subcategories may be distinguished’, as she worried that the D classification might be too encompassing and might subsume too many different forms of behaviour 
- William Emet Blatz
- John Bowlby
- Attachment theory
- Reactive attachment disorder
- Attachment measures
- Attachment in children
- Ainsworth, M. and Bowlby, J. (1965). Child Care and the Growth of Love. London: Penguin Books.
- Ainsworth, M. (1967). Infancy in Uganda. Baltimore: Johns Hopkins.
- Ainsworth, M., Blehar, M., Waters, E., & Wall, S. (1978). Patterns of Attachment. Hillsdale, NJ: Erlbaum.
- "Mary D. Ainsworth". Social Security Death Index. Retrieved 7 April 2011.[dead link]
- "Book of Members, 1780-2010: Chapter A". American Academy of Arts and Sciences. Retrieved 6 April 2011.
- Bretherton, I., & Ainsworth, M. D. S. (1974). One-year-olds in the Strange Situation. In M. Lewis & L. Rosenblum (Eds.), The Origins of Fear (pp. 134- 164), New York: Wiley.
- Sroufe, A. & Waters, E. (1977) Attachment as an Organizational Construct. Child Development, 48: 1184-1199
- Ainsworth, M.D., Blehar, M, Waters, E, & Wall, S. (1978) Patterns of Attachment: A Psychological Study of the Strange Situation, Hillsdale, NJ: Lawrence Erlbaum, p. 167
- Main, Mary; Solomon, Judith (1990). "Procedures for Identifying Infants as Disorganized/Disoriented during the Ainsworth Strange Situation". In Greenberg, Mark T.; Cicchetti, Dante; Cummings, E. Mark. Attachment in the Preschool Years: Theory, Research, and Intervention. Chicago: University of Chicago Press. pp. 121–60. ISBN 978-0-226-30630-8.
- Ainsworth, M. (1990). ‘Epilogue’ in Attachment in the Preschool Years, ed. M.T. Greenberg, D. Ciccheti & E.M. Cummings. Chicago, IL: Chicago University Press, pp.463-488.
- Landa, S. & Duschinsky, R. (2013) "Letters from Ainsworth: Contesting the ‘Organization’of Attachment." Journal of the Canadian Academy of Child and Adolescent Psychiatry 22.2
- O'Connell, A.N., & Rusoo, N.F. (1983). Models of achievement: Reflections of eminent women in psychology. New York: Columbia University Press.
- Mary Ainsworth on The Psi Cafe
- Mary Ainsworth profile on Psychology's Feminist Voices
- Women's Intellectual Contributions to the Study of Mind and Society
- Articles by Mary Ainsworth including summaries and links to full-text
- Transcript of oral history interview and CV (both in PDF format) from the Society for Research in Child Development
- Transcript of oral history interview (PDF) from the Canadian Psychological Association
- Episode about Mary Ainsworth from the BBC radio 4 program Mind Changers