The Impact of Expert Testimony on Jurors’ Decisions: Gender of the Expert and Testimony Complexity

The present study investigated whether people used the gender of an expert witness as a heuristic cue to evaluate the evidence presented by the expert. Specifically, the gender of the expert and the complexity of the expert’s testimony (low, high) were varied systematically within a simulated civil trial involving an antitrust price-fixing agreement, It was expected that the male expert would be more persuasive than the female expert, but only when the testimony presented was complex. As predicted, this interaction was revealed across a range of dependent measures. Somewhat unexpected was the finding of a female expert advantage in the low-complexity condition. The implications of these findings are discussed. In both civil and criminal cases, expert evidence is increasingly being proffered at trial (Gross & Syverund, 1991). As such, research on the topic of how jurors utilize expert information and the variables that influence its impact on jurors’ decisions is of increasing importance. Like any communicative message, the impact of expert testimony on jurors’ decisions is likely to be influenced by a range of variables, some of which are content related (e.g., quality of the testimony) and some of which are not (e.g., source characteristics of the expert). The focus of the present research is on expert gender, a non-content-related source characteristic that may, albeit unwittingly, influence jurors’ receptivity to the information conveyed by the expert. A handful of studies have provided some support for the notion that the gender of an expert witness may influence the degree to which the expert’s testimony impacts upon jurors’ decisions. Indeed, the observation that male experts are likely to be regarded as more credible than female experts (Memon & Shuman, 1998) is entirely consistent with the view that people tend to associate male targets with a wide variety of positive attributes that they fail to impart on female targets (Eagly, Makhijani, & Klonsky, 1992; Swim, Borgida, Maruyama, & Myers, 1989). Somewhat at odds with this initial impression, however, are results of studies comparing the impact of male versus female experts. These studies have found evidence for a female, rather than a male, expert advantage (Memon & Shuman, 1998; Schuller & Cripps, 1998; Swenson, Nash, & Roos, 1984). As the researchers have noted, however, the evidence for the persuasive superiority of the female expert witness in these studies may be a consequence of the female specific domain in which the effects of expert gender were examined (e.g., child custody, battered women). Indeed, given the theoretical literature on gender-role stereotyping and evaluations of men and women (e.g., Eagly et al. 1992; Swim et al., 1989), one might expect that the expert would be valued more, and hence have more of an impact, relative to his or her counterpart, when the domain of the case was gender congruent. More recently, Schuller, Terry, and McKimmie (2001) explored this hypothesis directly and found support for the interplay between the expert’s gender and the congruency of the case domain in which the expert testified, with the differential advantage of gender-role congruency primarily confined to the male congruent case (e.g., construction industry). By drawing on social psychological research on the topic of persuasion and attitude change (e.g., elaboration likelihood model; Petty & Cacioppo, 1986), the present study is designed to explore whether the gender of an expert might operate as a heuristic cue that jurors use to evaluate an expert’s testimony. As suggested by the longstanding research tradition in persuasion, people tend to use one of two cognitive routes-systematic or heuristicwhen evaluating a persuasive message (Chaiken, 1980; Petty & Cacioppo, 1986). Systematic or effortful processing involves a careful consideration of the quality of the message and its content, and requires both motivation and Journal of Applied Social Psychology (2005) 35 (6): 1266-1280. doi: 10.1111/j.1559-1816.2005.tb02170.x ability on the part of the individual to process the information. When people lack the motivation or ability to scrutinize and understand the message, however, researchers have demonstrated that people will turn to decisional shortcuts or heuristic cues to assess the quality of the message (Petty, Cacioppo, & Goldman, 1981; Ratneshwar & Chaiken, 1991). Drawing on this theoretical base, Cooper, Bennett, and Sukel (1 996) posited that, since expert testimony by its very nature tends to be complex, replete with specialized, technical, and scientific concepts (Faigman, Kaye, Saks, & Saunders, 2002), jurors may be especially sensitive to heuristic cues when evaluating expert testimony. To test this hypothesis, Cooper et al. presented mock jurors with a simulated civil trial in which the strength of the expert’s credentials (low, high) and the complexity of the expert testimony (low, high) were manipulated orthogonally. As expected, when the testimony was complex, Cooper et al. found that the mock jurors were more persuaded by an expert with highly credible credentials than by an expert with fewer credentials, a result that was not evident when participants were exposed to the simplified form of the testimony. In this latter condition, the influence of the expert’s credentials disappeared. In another series of experiments, Cooper and Neuhaus (2000) replicated and extended these results, again finding that the influence of peripheral cues was most pronounced when expert testimony was complex and not easily processed. As the findings of Cooper et al. (1996) suggest, variables that convey information about source credibility should have the most influence under conditions that limit the ability of an individual to systematically process and evaluate the content of a message. Drawing on this logic, the present study assesses whether expert gender might operate as a heuristic cue by orthogonally varying the complexity of the expert testimony and the gender of the expert within a simulated civil trial. If expert gender operates as a variable that conveys information about an expert’s level of expertise, it should have the greatest influence under conditions that limit the ability of an individual to systematically process and evaluate the content of the expert’s testimony. That is, the hypothesis that gender of expert operates as a heuristic cue that jurors will utilize to evaluate expert testimony if they are unable to systematically process the evidence is explored. In the present study, the potential for systematic processing was manipulated by varying directly the complexity of the expert testimony. Given that the gender effects found in Schuller et al. (2001) were primarily confined to the male-oriented domain considered in their research, the present study assesses the hypothesis in this condition only (i.e., male congruent condition). Based on the findings of Schuller et al., it is expected that if the testimony presented by the expert is highly complex, mock jurors will be more likely to rely on the peripheral cue of expert gender when evaluating the expert testimony. Thus, because of the male expert’s gender congruency with the domain of the case, it is expected that the male expert will exert a greater impact on the jurors’ awards and decisions than will his female expert counterpart. In contrast, the male expert advantage is not expected when the testimony is presented in a less complex and more comprehensible format, as such a presentation would permit participants to engage in a more systematic evaluation of the testimony, thereby reducing their reliance on the peripheral cue of gender.