Developmental differences in children’s learning and use of forensic ground rules during an interview about an experienced event.

Children often answer questions when they do not have the requisite knowledge or when they do not understand them. We examined whether ground rules instruction—to say “I don’t know,” to tell the truth, and to correct the interviewer when necessary—assisted children in applying those rules during an interview about a past event and whether doing so was associated with more accurate accounts. We compared children with intellectual disabilities (mild or moderate severity, n = 44, 7–12 years) with 3 groups of typically developing children (2 matched for mental age, and 1 for chronological age, n = 55, 4–12 years) on their understanding of 3 ground rules, their use of these rules in an interview, and their accuracy in recalling a personally experienced event. Many children were able to demonstrate proficiency with the rules following simple instruction but others required additional teaching. Children applied the rules sparingly in the interview. Their scores on the practice trials of each rule were unrelated to each other, and to the use of the rules in context. Their developmental level was significantly related to both of these skills. Regression models showed that developmental level was the best predictor of children’s accuracy when they recounted their experience during the interview but that use of responses consistent with the rules, in conjunction with developmental level, predicted accurate resistance to suggestive questions. Future research should identify how best to prepare children of different ages and cognitive abilities to answer adults’ questions appropriately.