The gestural misinformation effect in child investigative interviewing

To elicit uncontaminated memories from children, is the highest priority for investigative interviewers in criminal and legal proceedings. Police interviewers rarely rely on fully acceptable questioning techniques and defence lawyers may use inappropriate approaches on child eyewitnesses and victims, in an attempt to diminish their testimony. Despite various detailed guidelines and legal rules, on how to interview children in legal settings in Switzerland and the UK, the instructions mostly focus on question types and lack any references towards the influence of potential gestures by interviewers. The main aim of this thesis was to find out if gestures are commonly used in investigative interviews; and how they can influence children’s eyewitness statements and ultimately corrupt their memory. The thesis focused on two countries: Switzerland and England. Whilst there are a couple of studies that have investigated the influence of gestures in child interviews in England (Broaders & Goldin-Meadow, 2010; Kirk, Gurney, Edwards, & Dodimead, 2015), to our knowledge, no studies have been conducted in other countries, including Switzerland. Study 1 included interviews with Swiss police child interviewers, evaluating their guidelines and practices in regard to investigative child interviews. Study 2 investigated, whether investigative interviewers in Italy produced hand gestures when interviewing children. The Study found that interviewers produced a wide range of iconic gestures. Study 3 built on this and investigated whether misleading gestures during interviews could affect the correct responses of adults. It was found that the misleading gestures led to a decrease in correct responses and most participants were misled by at least one of the gestures. Study 4 then tested the gestural misinformation effect in children of three age groups. Results showed that the misleading gestures affected participants’ responses and led to a decrease in accuracy in children’s testimonies. Finally, Study 5 tested the gestural misinformation effect in children in England and Switzerland, in two delay conditions and between two age groups for a mock robbery video. Results confirmed the robustness of the gestural misinformation effect, irrespective of age, country or delay. Overall, it was concluded that gestures seem to be a common behaviour by interviewers and can negatively impact accurate eyewitness testimony of children. The findings have significant implications, demonstrating that non-verbal behaviour in form of gestures can alter children’s memory and thus, corrupt forensic investigations in police interviews.