What do eyewitnesses pay attention to? (Dan Reisberg) ch. 4

Throughout Chapter 4 in the textbook, we emphasized how little information people seem to gain about stimuli that are plainly visible (or plainly audible) if they are not paying attention to these stimuli. It's therefore crucial that we ask what eyewitnesses pay attention to during a crime. With that, what factors make it easier to pay attention? What factors distract the witness, so that he or she ends up noticing less and then reporting less in response to police questions?

One factor that seems crucial is the presence of a weapon. If, for example, a gun is on the scene, then it's sensible that crime witnesses will want to know whether the gun is pointed at them or not, whether the criminal's finger is on the trigger or not, and so on. After all, what else in the scene could be more important and more interesting to the witness? But with this focus on the weapon, many other things in the scene will be unattended, so that the witness may fail to notice, and later on fail to remember, many bits of information crucial for law enforcement.

Consistent with these suggestions, witnesses to crimes involving weapons often show a pattern called "weapon focus." They are able to report to the police many details about the weapon (its size, its color, and so on), and often many details about the hand that was holding the weapon (e.g., whether the person was wearing any rings or a bracelet). However, because of this focus, the witness may have a relatively poor memory for other aspects of the scene-including such forensically crucial information as what the perpetrator looked like. Indeed, many studies show that eyewitness identifications of the perpetrator are systematically less accurate in crimes involving weapons-presumably because the witness's attention was focused on the weapon, not on the perpetrator's face.

The weapon-focus pattern has been demonstrated in many studies, including studies that literally track where participants are pointing their eyes during the event. Scientists have used a statistical technique called meta-analysis, providing overall summary of these data, to confirm the reliability of this pattern, and, importantly, to show that the weapon-focus effect is stronger and more reliable in those studies that are closer to actual forensic settings. Thus, the weapon-focus effect seems not to be a peculiar by-product of the artificial situations created in the lab; indeed, the effect is probably underestimated in laboratory studies.

Demonstrations of the weapon-focus effect are important for many reasons, including the fact that they can help the courts in their evaluation of eyewitness testimony. After all, we obviously want to know when we can trust an eyewitness's recollection and when we cannot. More precisely, we want to know which aspects of the witness's recollection are likely to be accurate and which are not. To make these assessments, we need to know what factors shape a witness's memory, and it's on this basis that research on weapon focus can help us to make well-informed evaluations of each case, with the aim of maximizing the quality of courtroom evidence.

To learn more about this topic in cognitive psychology and the law:

See, in the textbook chapter, pages 103-111

*Loftus, E., Loftus, G., & Messo, J. (1987). Some facts about "weapon focus". Law and Human Behavior, 11, 55-62.

*Stanny, C. J., & Johnson, T. C. (2000). Effects of stress induced by a simulated shooting on recall by police and citizen witnesses. American Journal of Psychology, 113, 359-386.

Steblay, N. J. (1992). A meta-analytic review of the weapon focus effect. Law and Human Behavior, 16, 413-424.