Child and adult witnesses with intellectual disability: The importance of suggestibility

Abstract

Purpose. The main aim of the study was to examine the relationship between learning (intellectual) disability and interrogative suggestibility among children (11‐12 years old) and adults.Method. The Gudjonsson Suggestibility Scale (GSS 2) was administered to 110 children and 221 adults who were categorized into three groups according to fullscale IQ scores: (1) normal IQ (>75); (2) mild impairment (IQ score 55‐75); and (3) moderate impairment (IQ score <55).Results. Highly significant differences in memory and suggestibility emerged in both the child and adult samples across groups. Using memory as a covariate in the analysis eliminated the significant group differences for ‘yield 1’ among the children, but not for adults. There was no significant influence of memory on ‘shift’ in either group. Whereas ‘shift’ was significantly influenced by intellectual disability in children, no significant difference emerged across groups among adults.Conclusions. Children and adults with learning disability have much poorer memory and higher suggestibility scores than their contemporariesof normal intelligence. Differences in suggestibility are only partly explained by poorer memory scores. The findings reveal important differences between children and adults with intellectual disabilities. Children with learning disabilities are more susceptible to altering their answers under pressure than are adults with learning disabilities.