Understanding 'error' in the forensic sciences: A primer.

This paper distils seven key lessons about 'error' from a collaborative webinar series between practitioners at Victoria Police Forensic Services Department and academics. It aims to provide the common understanding of error necessary to foster interdisciplinary dialogue, collaboration and research. The lessons underscore the inevitability, complexity and subjectivity of error, as well as opportunities for learning and growth. Ultimately, we argue that error can be a potent tool for continuous improvement and accountability, enhancing the reliability of forensic sciences and public trust. It is hoped the shared understanding provided by this paper will support future initiatives and funding for collaborative developments in this vital domain.

A transparent approach: Openness in forensic science reporting.

There have been numerous calls for increased transparency and disclosure in forensic science. However, there is a paucity of guidance on how to achieve this transparency in reports, and the impacts it may have on criminal justice proceedings. We describe one multi-disciplinary forensic laboratory's journey to fully transparent reporting, disclosing matters of scientific relevance and importance. All expert reports across 17 disciplines now contain information regarding the fundamental principles and methodology, validity and error, assumptions and limitations, competency testing and quality assurance, cognitive factors, and areas of scientific controversy. Staff support for transparent reporting increased following introduction, with most reporting largely positive impacts. A slight increase in questioning in court has been experienced, with increased legal attention paid to the indicia of scientific validity. Transparency in expert forensic science reports is possible, and can improve the use of scientific evidence in courts without compromising the timeliness of service.

Tracking sexual dimorphism of facial width-to-height ratio across the lifespan: implications for perceived aggressiveness.

The facial width-to-height ratio (FWHR) influences social judgements like perceived aggression. This may be because FWHR is a sexually dimorphic feature, with males having higher FWHR than females. However, evidence for sexual dimorphism is mixed, little is known about how it varies with age, and the relationship between sexual dimorphism and perceived aggressiveness is unclear. We addressed these gaps by measuring FWHR of 17 607 passport images of male and female faces across the lifespan. We found larger FWHR in males only in young adulthood, aligning with the stage most commonly associated with mate selection and intrasexual competition. However, the direction of dimorphism was reversed after 48 years of age, with females recording larger FWHRs than males. We then examined how natural variation in FWHR affected perceived aggressiveness. The relationship between FWHR and perceived aggressiveness was strongest for males at 27-33 and females at 34-61. Raters were most sensitive to differences in FWHR for young adult male faces, pointing to enhanced sensitivity to FWHR as a cue to aggressiveness. This may reflect a common mechanism for evaluating male aggressiveness from variability in structural (FWHR) and malleable (emotional expression) aspects of the face.

Limited not lazy: a quasi-experimental secondary analysis of evidence quality evaluations by those who hold implausible beliefs.

Past research suggests that an uncritical or 'lazy' style of evaluating evidence may play a role in the development and maintenance of implausible beliefs. We examine this possibility by using a quasi-experimental design to compare how low- and high-quality evidence is evaluated by those who do and do not endorse implausible claims. Seven studies conducted during 2019-2020 provided the data for this analysis (N = 746). Each of the seven primary studies presented participants with high- and/or low-quality evidence and measured implausible claim endorsement and evaluations of evidence persuasiveness (via credibility, value, and/or weight). A linear mixed-effect model was used to predict persuasiveness from the interaction between implausible claim endorsement and evidence quality. Our results showed that endorsers were significantly more persuaded by the evidence than non-endorsers, but both groups were significantly more persuaded by high-quality than low-quality evidence. The interaction between endorsement and evidence quality was not significant. These results suggest that the formation and maintenance of implausible beliefs by endorsers may result from less critical evidence evaluations rather than a failure to analyse. This is consistent with a limited rather than a lazy approach and suggests that interventions to develop analytical skill may be useful for minimising the effects of implausible claims.

UNSW Face Test: A screening tool for super-recognizers.

We present a new test-the UNSW Face Test (www.unswfacetest.com)-that has been specifically designed to screen for super-recognizers in large online cohorts and is available free for scientific use. Super-recognizers are people that demonstrate sustained performance in the very top percentiles in tests of face identification ability. Because they represent a small proportion of the population, screening large online cohorts is an important step in their initial recruitment, before confirmatory testing via standardized measures and more detailed cognitive testing. We provide normative data on the UNSW Face Test from 3 cohorts tested via the internet (combined n = 23,902) and 2 cohorts tested in our lab (combined n = 182). The UNSW Face Test: (i) captures both identification memory and perceptual matching, as confirmed by correlations with existing tests of these abilities; (ii) captures face-specific perceptual and memorial abilities, as confirmed by non-significant correlations with non-face object processing tasks; (iii) enables researchers to apply stricter selection criteria than other available tests, which boosts the average accuracy of the individuals selected in subsequent testing. Together, these properties make the test uniquely suited to screening for super-recognizers in large online cohorts.

Improving face identification with specialist teams.

People vary in their ability to identify faces, and this variability is relatively stable across repeated testing. This suggests that recruiting high performers can improve identity verification accuracy in applied settings. Here, we report the first systematic study to evaluate real-world benefits of selecting high performers based on performance in standardized face identification tests. We simulated a recruitment process for a specialist team tasked with detecting fraudulent passport applications. University students (n = 114) completed a battery of screening tests followed by a real-world face identification task that is performed routinely when issuing identity documents. Consistent with previous work, individual differences in the real-world task were relatively stable across repeated tests taken 1 week apart (r = 0.6), and accuracy scores on screening tests and the real-world task were moderately correlated. Nevertheless, performance gains achieved by selecting groups based on screening tests were surprisingly small, leading to a 7% improvement in accuracy. Statistically aggregating decisions across individuals-using a 'wisdom of crowds' approach-led to more substantial gains than selection alone. Finally, controlling for individual accuracy of team members, the performance of a team in one test predicted their performance in a subsequent test, suggesting that a 'good team' is not only defined by the individual accuracy of team members. Overall, these results underline the need to use a combination of approaches to improve face identification performance in professional settings.

Stereoscopic advantages for vection induced by radial, circular, and spiral optic flows.

Although observer motions project different patterns of optic flow to our left and right eyes, there has been surprisingly little research into potential stereoscopic contributions to self-motion perception. This study investigated whether visually induced illusory self-motion (i.e., vection) is influenced by the addition of consistent stereoscopic information to radial, circular, and spiral (i.e., combined radial + circular) patterns of optic flow. Stereoscopic vection advantages were found for radial and spiral (but not circular) flows when monocular motion signals were strong. Under these conditions, stereoscopic benefits were greater for spiral flow than for radial flow. These effects can be explained by differences in the motion aftereffects generated by these displays, which suggest that the circular motion component in spiral flow selectively reduced adaptation to stereoscopic motion-in-depth. Stereoscopic vection advantages were not observed for circular flow when monocular motion signals were strong, but emerged when monocular motion signals were weakened. These findings show that stereoscopic information can contribute to visual self-motion perception in multiple ways.