Mary Main (born 1943) is a researcher at University of California, Berkeley.
Together with Judith Solomon, Main identified and empiricized a fourth attachment style in children, namely an insecure disorganized attachment classification. In the Strange Situation, the attachment system is expected to be activated by the departure and return of the caregiver. If the behaviour of the infant does not appear to the observer to be coordinated in a smooth way across episodes to achieve either proximity or some relative proximity with the caregiver, then it is considered 'disorganised' as it indicates a disruption or flooding of the attachment system (e.g. by fear). Infant behaviours in the Strange Situation Protocol coded as disorganised/disoriented include overt displays of fear; contradictory behaviours or affects occurring simultaneously or sequentially; stereotypic, asymmetric, misdirected or jerky movements; or freezing and apparent dissociation. However, Lyons-Ruth has qualified that '52% of disorganized infants continue to approach the caregiver, seek comfort, and cease their distress without clear ambivalent or avoidant behavior'.
There is a growing body of research on the links between abnormal parenting, disorganized attachment and risks for later psychopathologies. Abuse is associated with disorganized attachment; yet a parent’s ongoing experience of an anxiety-disorder or multiple forms of social and economic disadvantage have also been found to predict disorganised attachment in the infant  - which is why it is not appropriate to use disorganised attachment as a screening tool for abuse. The disorganized style is a risk factor for a range of psychological disorders although it is not in itself considered an attachment disorder under the current classification. For example, longitudinal research by Sroufe, Egeland and Carlson has found that a classification of disorganised/disoriented attachment in infancy has a .36 association with dissociative symptoms in adolescence.
Mary Main is also co-author of the Adult Attachment Interview (AAI) which uses questionnaire and interview to assess attachment status of adults. Developed by Carol George, Nancy Kaplan, and Mary Main in 1984, this is a quasi-clinical semi-structured interview that takes about one hour to administer. It involves about twenty questions and has extensive research validation to support it. The AAI Protocol is available for review.
- Main, M., Hesse, E., & Kaplan, N. (2005). Predictability of attachment behaviour and representational processes at 1, 6, and 18 years of age: The Berkeley Longitudinal Study. In K.E. Grossmann, K. Grossmann & E. Waters (Eds.), Attachment from Infancy to Adulthood. pp. 245–304. New York: Guilford Press.
- 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, Attachment during the preschool years: Theory, research and intervention. pp. 121–160. Chicago: University of Chicago Press.
- Main M, Solomon J (1986). "Discovery of an insecure disoriented attachment pattern: procedures, findings and implications for the classification of behavior". In Brazelton T, Youngman M. Affective Development in Infancy. Norwood, NJ: Ablex. ISBN 0-89391-345-6.
- Main, M & Solomon, J., (1990). In Greenberg, M. T., Cicchetti, D., & Cummings, M. (Eds.),. Attachment in the preschool years: Theory, research, and intervention (pp. 121-160). The University of Chicago Press: Chicago.
- Karlen Lyons-Ruth, Jean-Francois Bureau, M. Ann Easterbrooks, Ingrid Obsuth, Kate Hennighausen & Lauriane Vulliez-Coady (2013) Parsing the construct of maternal insensitivity: distinct longitudinal pathways associated with early maternal withdrawal, Attachment & Human Development, 15:5-6, 570
- Zeanah CH, Keyes A, Settles L (2003). "Attachment relationship experiences and childhood psychopathology". Ann. N. Y. Acad. Sci. 1008: 22–30. doi:10.1196/annals.1301.003. PMID 14998869.
- Van IJzendoorn M. H., Schuengel C., Bakermans Kranenburg M. J. (1999). Disorganized attachment in early childhood: Meta-analysis of precursors, concomitants, and sequelae. Development and Psychopathology, 11, 225-249.
- Carlson, V.; Cicchetti, D.; Barnett, D.; Braunwald, K. (1989). "Disorganized/disoriented attachment relationships in maltreated infants". Developmental Psychology 25: 525–531. doi:10.1037/0012-16220.127.116.115.
- Cyr, C., Euser, E. M., Bakermans-Kranenburg, M. J., & Van IJzendoorn, M. H. (2010). Attachment security and disorganization in maltreating and high-risk families: A series of meta-analyses. Development and Psychopathology, 22, 87-108
- Manassis K., Bradley S., Goldberg S., Hood J., Swinson R. (1994) Attachment to mothers with anxiety disorders and their children. Journal of the American Academy of Child and Adolescent Psychiatry 33: 1106–13
- Main, M., Hesse, E. & Hesse, S. (2011) Attachment theory and research: Overview with suggested applications to child custody. Family Court Review, 49(3): 426–463
- Lyons-Ruth K, Jacobvitz C (1999) "Attachment Disorganization: Unresolved Loss, Relational Violence, and Lapses in Behavioral and Attentional Strategies". In Cassidy J and Shaver PR (Eds.) Handbook of Attachment: Theory, Research and Clinical Applications. pp. 89—111. Guilford Press ISBN 1-57230-087-6.
- Lyons-Ruth K, Yellin C, Helnick S, Atwood G (2005). "Expanding the concept of unresolved mental states: Hostile/Helpless states of mind on the Adult Attachment Interview are associated with disrupted mother-infant communication and infant disorganization". Dev Psychopathol 17: 1–23. doi:10.1017/S0954579405050017. PMC 1857275. PMID 15971757.
- Sroufe, A. Egeland, B., Carlson, E. & Collins, W.A. (2005) The Development of the Person, NY: Guilford Press