Attachment in adults with intellectual disabilities; The examination of the psychometric properties of the Manchester Attachment Scale- Third Party Observational Measure (MAST)

  • Victoria Penketh

Student thesis: Doctor of Clinical Psychology


Introduction: Research indicates that children with an intellectual disability [ID] are at an increased risk of developing attachment difficulties and subsequent affect regulation difficulties. Attachment theory may further understanding of the risk factors for individuals with an ID experiencing mental health problems, challenging behaviour and emotional difficulties. However, there is a paucity of research into attachment and adults with ID and there is a lack of valid and reliable measures for assessing attachment security for this group. The Manchester Attachment Scale-Third Party Observational Measure [MAST] was developed to assess degree of secure attachment behaviour for adults with ID and the current study examined the psychometric properties of the MAST. Method: Professional carers [N=40] supporting individuals with an ID completed the MAST and other measures related to the construct of attachment theory (subscales of the Edward Zigler-Yale Personality Questionnaire[EZPQ] and Emotional Rating Scale [ERS] as well as the Learning Disability Casemix Scale [LDCS) regarding individuals with an ID they were supporting [N=57]. Individuals with an ID [N=14] completed the Self-report Assessment of Attachment Security [SRAAS].Results: The MAST was found to have good internal consistency and test-retest reliability. The convergent validity of the MAST was indicated by positive correlation with the EZPQ subscales (negative reaction tendency, obedience, positive reaction tendency and outerdirectedness) and scores on the SRAAS. The MAST was found to be correlated with both levels of ID and presence of challenging behaviour as measured by LDCS scores. Conclusion: These current results provide preliminary support for the reliability and validity of the MAST as a measure of secure attachment behaviour for adults with ID. The results provide support for previous research that indicates a relationship between attachment security and level of ID and challenging behaviour. The results of the study and the implications of attachment theory for adults with ID are discussed.
Date of Award31 Dec 2011
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorDougal Hare (Supervisor)


  • Attachment theory
  • Adults with intellectual disabilities

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