Repetition of contaminating question types when children and youths with intellectual disabilities are interviewed

Background: The present study analyzed the effect of question repetition in investigative interviews about alleged sexual abuse with children and youths with a variety of learning disabilities (developmental disorder/autism spectrum disorder). We predicted that repetition of option-posing and suggestive questions would lead to changes in responses which are problematic when trying to understand what actually happened. Inconsistency can be a key factor when assessing the trustworthiness of a testimony.
Materials: Transcripts of investigative interviews and case files of 33 children and youths who have a variety of learning disabilities were obtained from prosecutors in Sweden. The interviews involved 25 females and 9 males whose chronological ages were between 5.4 and 23.7 years when interviewed (M = 13.2 years).
Results: Questions were repeated at least once 6% of the time in the interviews examined. The unnecessary use of repeated focused questions may have contaminated the reports because children and youths with variety of learning disabilities changed their answers 40% of the time.
Conclusions: Regardless of the witnesses’ abilities, it is important to obtain reports that are as accurate and complete as possible in investigative interviews. Because this was a field study we did not know which responses were accurate, but repetitions of potentially contaminating questions caused contradictions of previous answers. This means that interviewers’ behavior can cause a serious risk of decreasing the usefulness of these witnesses’ evidence in legal contexts.