Knowledge of legal professionals about age trends in false memory propensity: a vignette study.

Professionals who evaluate witness testimony must understand the developmental factors that can affect statements credibility. This online vignette study investigated in how far 102 legal professionals (e.g., judges, attorneys, and police officers) were aware of age-related differences in false memory formation (e.g., the developmental reversal effect). Swedish, Norwegian, and Dutch legal professionals received a case vignette about a female who had witnessed her mother's murder. We manipulated witness age (6 versus 22 years old) and disclosure (spontaneous versus suggestion-induced). Legal professionals rated the case and statement on several credibility, metacognition, and belief items. Main effects of both age and disclosure indicated that professionals were statistically more likely to assume that the case referred to a false memory when the witness was 6 (versus 22) years old and when the witness had talked to her grandmother (versus spontaneous statement) before her disclosure to the police. The 6-year-old witness was rated as more reliable than the 22-year-old witness. Professionals were more likely to consider the opinion of a memory expert when the witness was 6 years old rather than 22 years old. This study emphasizes the need for raising awareness among legal professionals about developmental factors related to validity assessment.