The Adult Attachment Projective Picture System: a pilot study of inter-rater reliability and face validity with adults with intellectual disabilities

Abstract

Purpose The purpose of this paper is to assess whether the Adult Attachment Projective (AAP) Picture System is a reliable and face valid measure of internal working models of attachment in adults with intellectual disabilities (ID). Design/methodology/approach The AAPs of 20 adults with ID were coded blind by two reliable judges and classified into one of four groups: secure, dismissing, preoccupied, or unresolved. Inter-rater reliability was calculated using κ. Six participants repeated the assessment for test-retest reliability. Two independent experts rated ten cases on the links between the AAP analysis and the clinical history. Findings There was significant agreement between AAP judges, κ=0.677, p<0.001. Five out of six participants showed stability in their classifications over time. The majority of expert ratings were “good” or “excellent”. There was a significant inter-class correlation between raters suggesting good agreement between them r=0.51 (p<0.05). The raters’ feedback suggested that the AAP had good clinical utility. Research limitations/implications The inter-rater reliability, stability, face validity, and clinical utility of the AAP in this population is promising. Further examination of these findings with a larger sample of individuals with ID is needed. Originality/value This is the first study attempting to investigate the reliability and validity of the AAP in this population.