GFMT2: A psychometric measure of face matching ability

We present an expanded version of a widely used measure of unfamiliar face matching ability, the Glasgow Face Matching Test (GFMT). The GFMT2 is created using the same source database as the original test but makes five key improvements. First, the test items include variation in head angle, pose, expression and subject-to-camera distance, making the new test more difficult and more representative of challenges in everyday face identification tasks. Second, short and long versions of the test each contain two forms that are calibrated to be of equal difficulty, allowing repeat tests to be performed to examine effects of training interventions. Third, the short form tests contain no repeating face identities, thereby removing any confounding effects of familiarity that may have been present in the original test. Fourth, separate short versions are created to target exceptionally high performing or exceptionally low performing individuals using established psychometric principles. Fifth, all tests are implemented in an executable program, allowing them to be administered automatically. All tests are available free for scientific use via www.gfmt2.org.

The effect of face masks and sunglasses on identity and expression recognition with super-recognizers and typical observers

Face masks present a new challenge to face identification (here matching) and emotion recognition in Western cultures. Here, we present the results of three experiments that test the effect of masks, and also the effect of sunglasses (an occlusion that individuals tend to have more experienced with) on (i) familiar face matching, (ii) unfamiliar face matching and (iii) emotion categorization. Occlusion reduced accuracy in all three tasks, with most errors in the mask condition; however, there was little difference in performance for faces in masks compared with faces in sunglasses. Super-recognizers, people who are highly skilled at matching unconcealed faces, were impaired by occlusion, but at the group level, performed with higher accuracy than controls on all tasks. Results inform psychology theory with implications for everyday interactions, security and policing in a mask-wearing society.

Epilogue

This book has provided an overview of the latest developments and current understanding of forensic/unfamiliar face matching. Throughout this book, the scientific study of face matching has been contextualized through two important applied tasks—facial comparison at passport control and in police settings. These applied tasks are now considered in turn to draw together content from different chapters and highlight some of the key insights emerging from this book....

Steps Towards a Cognitive Theory of Unfamiliar Face Matching

The visual comparison of unfamiliar faces—or ‘face matching’—is utilized widely for person identification in applied settings and has generated substantial research interest in psychology, but a cognitive theory to explain how observers perform this task does not exist. This chapter outlines issues of importance to support the development of a cognitive account of unfamiliar face matching. Characteristics of the face, such as within-person variability and between-person similarity in appearance, are considered as the visual input upon which identification must build. The cognitive mechanisms that observers may bring to bear on faces during identity comparison are analysed, focusing on attention, perception, evaluation, and decision processes, including sources of individual differences at each of these stages. Finally, the role of different experimental and occupational contexts in understanding face matching and for optimizing theory development is discussed.

Understanding Professional Expertise in Unfamiliar Face Matching

Deciding whether or not two images are of the same unfamiliar face is an important task in many professions. These decisions are a critical part of modern identity verification processes with direct—and often profound—consequences for individual rights and the security of society. As a result, the public expect the people entrusted with these decisions to perform accurately. But do they? Here we review 29 published tests comparing face matching accuracy in professional and novice groups. Twelve of these tests show no significant differences between professional and novice groups, suggesting that merely performing the task in daily work is not sufficient to improve accuracy. However, specialist groups of facial examiners and police super-recognizers consistently outperform novices. Staff selection, mentorship, deliberate practice, motivation, feedback and training may all contribute to enhancing the performance of individuals working in these groups, and future research is necessary to delineate their relative contributions.

Understanding professional expertise in unfamiliar face matching

Deciding whether or not two images are of the same unfamiliar face is an important task in many professions. These decisions are a critical part of modern identity verification processes with direct – and often profound – consequences for individual rights and the security of society. As a result, the public expect the people entrusted with these decisions to perform accurately. But do they? Here we review 29 published tests comparing face matching accuracy in professional and novice groups. Twelve of these tests show no significant differences between professional and novice groups, suggesting that merely performing the task in daily work is not sufficient to improve accuracy. However, specialist groups of Facial Examiners and Police Super- recognisers consistently outperform novices. Staff selection, mentorship, deliberate practice, motivation, feedback and training may all contribute to enhancing the performance of individuals working in these groups and future research is necessary to delineate their relative contributions.

Performance of Typical and Superior Face Recognisers on a Novel Interactive Face Matching Procedure

Unfamiliar simultaneous face matching is error prone. Reducing incorrect identification decisions will positively benefit forensic and security contexts. The absence of view-independent information in static images likely contributes to the difficulty of unfamiliar face matching. We tested whether a novel interactive viewing procedure that provides the user with 3D structural information as they rotate a facial image to different orientations would improve face matching accuracy. We tested the performance of ‘typical’ (Experiment 1) and ‘superior’ (Experiment 2) face recognisers, comparing their performance using high quality (Experiment 3) and pixelated (Experiment 4) Facebook profile images. In each trial, participants responded whether two images featured the same person with one of these images being either a static face, a video providing orientation information, or an interactive image. Taken together, the results show that fluid orientation information and interactivity prompt shifts in criterion and support matching performance. Because typical and superior face recognisers both benefited from the structural information provided by the novel viewing procedures, our results point to qualitatively similar reliance on pictorial encoding in these groups. This also suggests that interactive viewing tools can be valuable in assisting face matching in high performing practitioner groups.

The sibling familiarity effect: Is within-person facial variability shared across siblings?

Humans are experts at familiar face recognition, but poor at unfamiliar face recognition. Familiarity is created when a face is encountered across varied conditions, but the way in which a person’s appearance varies is identity-specific, so familiarity with one identity does not benefit recognition of other individuals. However, the faces of biological siblings share structural similarities, so we explored whether the benefits of familiarity are shared across siblings. Results show that familiarity with one half of a sibling pair improves kin detection (experiment 1), and that unfamiliar face matching is more accurate when targets are the siblings of familiar vs unfamiliar individuals (experiment 2). PCA applied to facial images of celebrities and their siblings demonstrates that, for shape, faces are generally better reconstructed in the principal components of a same-sex sibling than those of an unrelated individual. When we encounter the unfamiliar sibling of someone we already know, our pre-existing representation of their familiar relation may usefully inform processing of the unfamiliar face. This can benefit both kin detection and identity processing, but the benefits are constrained by the degree to which facial variability is shared.