Adjusting the focus of attention: Helping Witnesses to Evolve a More Identifiable Composite

Abstract

When perceiving faces under normal circumstances, the focus of attention is likely to be on the upper (e.g., hair, eyes) than lower (e.g., mouth, chin) facial half [1]. If such a bias were to extend to face construction, then it may hinder the effectiveness of forensic evidence collected from witnesses and victims of crime. In Experiment 1, participants constructed a single face using the EvoFIT holistic (police) composite system 24 hours after having seen an unfamiliar target identity. When constructing the face, participants were asked to select items from face arrays based on the whole face, or for upper and lower facial halves separately; these faces were presented in arrays either intact or horizontally-misaligned [2], and with external features (hair, ears, neck) present or absent. More-identifiable composites were predicted from (i) selection of separate facial halves (cf. currently-used whole-face selection), (ii) presence of horizontal misalignment and (iii) absence of external features. Experiment 2 used the same basic design but participants were requested to select for (i) upper-face half during evolution, (ii) the same as (i) but also for subsequent adjustments of the face, and (iii) overall face (Control). The composites constructed in both experiments were named and rated for likeness. Experiment 1 unexpectedly revealed that the Control group produced the highest-named composites. In Experiment 2, upper face selection during the evolution stage produced more-effective composites. In terms of practical implications, for the EvoFIT composite system, and potentially for other holistic systems, witnesses should be instructed to select faces for the upper facial half during evolution, to maximise subsequent identification of their composites.