The influence of social instructions on the effectiveness of a cognitive interview used with very young child witnesses

IntroductionThe modified cognitive interview (MCI) is an investigative interview method used to help child eyewitnesses to enhance the quality of their testimonies (Memon et al., 2010). Composed of cognitive (mnemonics) and social instructions, it indeed supports young witnesses to retrieve and to accurately report all their memories. If the benefits of the mnemonics on the MCI efficiency have been now established (e.g., Holliday & Albon, 2004; Verkampt & Ginet, 2010), the contribution of its social components has however not been deeply explored to date. This is notably the case of two main social instructions presented at the right beginning of an interview: the “Child can say ‘I don’t know”’ and the “Interviewer knows nothing about the facts” instructions.ObjectiveThis study aimed at evaluating the influence of these two social instructions on the effectiveness of MCI mnemonics, designed to be used by police officers to gather very young children's testimonies.MethodTo this end, 59 children aged 4 to 5.9 participated in a painting session and were interviewed two days later with a full modified cognitive interview (MCI), a MCI minus the “Child can say I don’t know” instruction, a MCI minus the “Interviewer knows nothing about the event” instruction, or a structured (control) interview that was solely composed of social instructions.ResultsThe results indicated an increase of 42% more correct information recollected with a full MCI relative to a structured interview during the free recall phase. However, the withdrawal of the “Interviewer knows nothing about the event” instruction from the MCI led the children to report 21% less information. This drop reached 3% with the MCI minus the “Child can say I don’t know” instruction.ConclusionChildren testimonies are therefore more informative when the mnemonics of the MCI are presented to the children along with social instructions.