Inattentional blindness in eyewitnesses to crime: Consequences for eyewitness safety, memory and credibility

Abstract

When attention is focused elsewhere, individuals may fail to notice unexpected events in plain sight, a phenomenon known as inattentional blindness (IB: Mack & Rock, 1998). In legal settings, eyewitnesses may experience IB and fail to notice entire crimes occurring (Hyman, 2016). The current thesis aimed to assess the impact of IB on eyewitness safety, memory, and credibility. In the first two studies, IB for an assault crime was measured. The presence of a weapon was manipulated (Study 1), and memory for the crime was assessed (Study 1 & Study 2). The results showed that weapon presence did not impact rates of IB. Study 1 found that IB impacted the quantity, but not quality, of witness memory. However, when manipulating the recall instructions in Study 2, IB negatively affected both the quantity and quality of memory. Given that witnesses who experience IB may testify in court, subsequent studies were conducted to explore perceptions of eyewitness IB. In Study 3, lawyers, psychology students, and members of the public were surveyed regarding their beliefs about IB in legal scenarios. All populations overestimated visual detection across most legal scenarios. In Studies 4 and 5, mock-jurors read a trial containing two key witnesses: one who saw the crime, and one who experienced IB. Both studies showed that the witness who experienced IB was perceived as less credible than the witness who saw the crime. In Study 5, several factors (witness role, witness familiarity with defendant, and expert testimony) did not influence the negative perceptions of IB. Therefore, Studies 6 and 7 aimed to determine whether demonstrating IB and providing expert testimony on IB would improve perceptions of witness IB. Neither demonstrating IB nor expert testimony rectified the negative perceptions of witness IB. The findings within this thesis indicate that IB among eyewitnesses presents a unique challenge in criminal settings.