Impact of expert psychological testimony on the unreliability of eyewitness identification.

Abstract

The purpose of the present research was to study the influence on jurors of expert testimony about eyewitness identification. In Experiment 1 240 students (all registered voters) acted as jurors and received evidence against a defendant in a violent or a nonviolent case. The major piece of prosecution evidence was the testimony of the eyewitness. Half of the jurors read about the testimony of a defense expert on the reliability of eyewitness identification, whereas half did not. Individual verdicts were reached. The results indicated that there were fewer convictions when expert testimony was permitted. In Experiment 2 120 students received evidence in a hypothetical violent crime and then deliberated injuries of 6 to reach a verdict for or against the defendant. Jurors who had read about the expert testimony spent much more time discussing the eyewitness account than did jurors who had not been presented with expert testimony. The results indicate that one consequence of presenting psychological expert testimony is an increase in the amount of attention that jurors give to eyewitness accounts, perhaps enhancing their scrutinization. Some pros and cons of the psychological expert testimony are discussed.

Expert evidence by psychologists: Sometimes problematic and often premature

“…Psychologists have also investigated the assumption that the expert may have undue influence on the trier of fact (e.g., Hosch, Beck, & McIntyre, 1980;Loftus, 1980: Wells, Lindsay, & Tousignant, 1980. These studies have involved presenting mock jurors with selected portions of the evidence from a criminal trial.…”

Hippocampal and cortical place cell plasticity: Implications for episodic memory

“…Short day 1 experiences were associated with increased plasticity on day 2. (Loftus, 1980;Hyman and Loftus, 1998). We hypothesize that the encoding of episodic memories puts the hippocampus in a high plasticity state, and that unless sufficient time is available to solidify the newly formed memories, these memories may be easily disrupted by subsequent experiences.…”

Expert testimony and jury decision making: An empirical analysis

“…An important limitation of most previous studies (Fox & Walters, 1986;Katzev & Wishart, 1985; Loftus, 1980;Maass et al, 1985) is that they exclusively used undergraduates as subjects. Exceptions to this work include Hosch and colleagues (1980), who used undergraduates in one phase of the study and community members enrolled in a continuing education program in another phase of the study.…”