Evidence Evaluation and Evidence Integration in Legal Decision‐Making: Order of Evidence Presentation as a Moderator of Context Effects

Abstract

Legal decision-making studies often demonstrate context effects: People's initial beliefs about a suspect's guilt influence their evaluation of subsequent evidence. We examine three potential moderators of these context effects: Order of evidence presentation, ability to ruminate, and valence of the initial belief (innocence or guilt). College students (n = 382) were presented with DNA evidence (incriminating or exonerating) and an ambiguous alibi in one of two orders (or just the alibi), and then evaluated how strongly the alibi incriminated the suspect and the suspect's likelihood of guilt. Results indicated that alibi evaluation exhibited context effects when (i) initial beliefs were of guilt (but not of innocence) and when (ii) evaluating subsequent evidence (but not when retroactively evaluating prior evidence). Rumination failed to moderate any effects. The integration of evidence exhibited recency effects: DNA had a greater impact on participants' beliefs in the suspect's guilt when presented last rather than first.

Law and order effects: on cognitive dissonance and belief perseverance

“…Moreover, they concluded that the piece of evidence that is presented last does not retroactively influence evaluations of the evidence that was presented earlier. However, similarly to the finding by Price and Dahl (2014), Charman et al (2016) also found that the piece of evidence that was presented last had a greater impact on the overall assessment of guilt. Charman et al (2016) therefore suggested that evidence evaluation is likely to be influenced by an existing belief, whereas the evidence integration is likely to be influenced by a recency effect.…”

“…However, similarly to the finding by Price and Dahl (2014), Charman et al (2016) also found that the piece of evidence that was presented last had a greater impact on the overall assessment of guilt. Charman et al (2016) therefore suggested that evidence evaluation is likely to be influenced by an existing belief, whereas the evidence integration is likely to be influenced by a recency effect. As these studies on order effects looked only at the presentation of two pieces of evidence, the effect of alternating the presentation of incriminating and exonerating evidence remains unexamined.…”

“…The finding of such a recency effect is contrary to what would be expected in line with belief perseverance; belief perseverance can be considered a form of primacy effect, where the conclusion is based disproportionately on the initial evidence. Charman et al (2016) made use of DNA evidence and alibi evidence to test the influence of order of presentation. They concluded that the initial evidence had an influence on the evaluation of subsequent evidence, which can be considered supportive of a primacy effect and belief perseverance.…”

The influence of suspect ethnicity and evidence direction on alibi credibility assessment

“…Similarly, police trainees had greater faith in incriminating evidence that confirmed their expectations regarding a suspect's guilt (Marksteiner et al, 2011). This phenomenon is also supported by evidence of a primacy effect in evidence evaluation, such that the first piece of evidence, which presumably sets expectations, influences the evaluation of subsequent pieces (Charman et al, 2017; Charman, Carbone, Kekessie, & Villalba, 2016). While these and other studies have established that cognitive biases affect evidence evaluation in forensic contexts (see Ask et al, 2008; Charman et al, 2016; Ruva & Guenther, 2017), there is currently limited research on the extent to which evidence direction (incriminating versus exonerating) moderates the influence of ethnicity on alibi credibility assessments.…”

Challenges of a “toolbox” approach to investigative interviewing: A critical analysis of the Royal Canadian Mounted Police’s (RCMP) Phased Interview Model.

“…In terms of forensic evidence, some of the types of evidence that are presented in the PIM manual as compelling forms of evidence (Carr, 2015, p. 188)such as tire impressions, tool marks, and blood spatter analysisare, in fact, unsupported by scientific research (National Research Council, 2009; see also Cediel & Bergman, 2012). Additionally, forensic psychology research suggests that case information has the power to taint the interpretation and integration of forensic evidence (e.g., Charman, 2013;Charman, Carbone, Kekessie, & Villalba, 2016;Dror, Charlton, & Péron, 2006;Kassin, Bogart, & Kerner, 2012;Kassin, Dror, & Kukucka, 2013).…”