East Carolina University
Department of Psychology
Poulson, R. L., Wuensch, K. L., Brown, M. B, & Braithwaite, R. L. (1997). Mock jurors' evaluations of insanity defense verdict selection: The role of death penalty attitudes. Journal of Social Behavior and Personality, 12, 1065-1078.
The present study examined the impact of mock jurors' attitudes toward the death penalty on their evaluations of critical components of an insanity defense trial. These critical components included jurors' evaluations of the efficacy of the insanity defense, expert psychological testimony, the defendant's mental status and, importantly, their subsequent verdicts. A mock trial was presented to 137 college student participants by means of an audio tape and slide show. Following the reenacted trial, participants answered a series of questions regarding the case. Statistical analyses revealed significant associations between jurors' attitudes toward the death penalty and their evaluations of the efficacy of the insanity defense, the accuracy of expert testimony, the defendant's mental status, and their final verdict selections. Mock jurors who favored the death penalty were more accepting of the prosecution's expert testimony, less believing that the crime was a result of the defendant's mental illness, and less believing in the efficacy of the insanity defense itself. Moreover, those mock jurors who held pro-death penalty attitudes were significantly less willing to find the defendant Not Guilty by Reason of Insanity.
The present study was designed to assess the relationship between mock jurors' attitudes toward the death penalty and their insanity defense verdicts. It was also designed to determine whether mock jurors' death penalty attitudes are related to their evaluation of two important insanity defense correlates, namely: the defendant's mental status and the expert testimony provided by both defense and prosecution expert witnesses.
The importance of this research is based on the idea that when pleading insanity in a capital case, a defendant may be at a distinct disadvantage because all those who have serious reservations about the death penalty are generally eliminated from such capital cases. Whether this possible absence of ideal juror neutrality manifests itself in mock jurors' insanity defense verdict selections is the major focus of the present study.
Juror Attitudes and Verdict Selections
Central to our investigation is the widely held assumption that knowledge of jurors' attitudes facilitates the prediction of their verdicts. This belief is reflected in the "voirdire" or jury selection process, where attorneys and the trial judge have the opportunity to assess the attitudes, beliefs and prejudices of potential jurors. This information is then used to decide if a potential juror is impartial and therefore suitable to serve on the jury.
While some studies (i.e., Roberts & Golding, 1991; Saks, 1976; Saks & Has tie, 1978; Simon, 1967) reported an almost negligible relationship between jurors' attitudes and their verdict selections, other studies (Cowan, Thompson, & Ellsworth, 1984; Goldberg, 1970; Jurow, 1971; Poulson, 1988) have shown that jurors' attitudes do influence their evaluations of the evidence and ultimately their final verdict selections. For example, mock jurors' attitudes toward the death penalty have consistently been found to predict verdict choice. Jurors who are willing to apply the death penalty are called "death qualified." Death-qualified jurors tend to show a greater orientation toward crime control, regard prosecuting attorneys more favorably, are more suspicious of attorneys for the defense, and believe that it is better to convict someone who is innocent than release some who are guilty (Fitzgerald & Ellsworth, 1984; Jurow,1971; Luginbuhl & Middendorf, 1988; Thompson, Cowan, Ellsworth, & Harrington, 1984; Vidmar & Ellsworth, 1974).
With specific regards to the insanity defense, research conducted by Ellsworth, Bukaty, Cowan, and Thompson (1984) shows that death qualified jurors were significantly less willing to render a verdict of not guilty by reason of insanity.(n1) This apparent relationship was qualified by the type of disorder from which the defendant was said to have suffered When the defendant was alleged to have suffered from an organic mental disorder, namely retardation or psychomotor epilepsy, no significant effects were observed. It was only when the defendant was alleged to have suffered from a nonorganic disorder, namely schizophrenia of a paranoid or schizoaffective type, that a significant association was observed between mock jurors' beliefs about the death penalty and their verdict selections. It appears that under certain conditions the defendant's mental disorder exceeded mock jurors' thresholds for attributing criminal responsibility--even those who may have favored the death penalty.
Evaluation of the Defendant's Mental Status
Other research revealed that jurors' evaluations of the defendant's mental disorder significantly affected their verdict selections (Finkel & Handel, 1989; Poulson, 1988; Poulson, 1990; Poulson, Braithwaite, Brondino, & Wuensch, 1997; Roberts, Golding, & Fincham, 1987). For example, using verdict choice (i.e., guilty, not guilty by reason of insanity, and not guilty) as the independent variable, Poulson (1988) found that jurors who returned a not guilty by reason of insanity verdict differed significantly in their evaluation of the defendant's mental status from jurors who returned straight guilty verdicts. Research conducted by Finkel and Handel (1989) produced similar results in that jurors who opted for the straight guilty verdict differed in their assessments of the defendant's mental status from jurors who voted not guilty by reason of insanity. These results together with data from previous studies (e.g., Ellsworth et al., 1984; Simon, 1967) suggest that jurors' verdict preferences are related to how they assess the defendant's mental status at the time of the alleged offense.
We should emphasize that, although the evidence presented in these simulated studies (Finkel & Handel, 1989; Poulson, 1990; Roberts et al., 1987) was held constant, jurors still reached different verdicts. This suggests that evidence related to the defendant's overall mental status may be evaluated by jurors in different ways, which, of course, may account for the disparity in their verdict selections. We hypothesize that mock jurors' evaluations of the defendant's mental status and their subsequent verdict selections will be significantly associated with their death penalty attitudes.
Evaluation of Expert Psychological Testimony
A number of researchers (e.g., Guttmacher, 1955; Hosch, 1980; James, 1960; Perlin, 1975) have identified the important role of expert testimony in jurors' decision making. In 1960, James conducted a study of juror evaluation of expert psychiatric testimony using mock jurors.
The study revealed that 74% of mock jurors believed psychiatric testimony was helpful in choosing a verdict. Additionally, the mock jurors reported that only the testimony of the complaining witnesses was of greater importance in making their decisions (lames, 1960). The acceptance of expert testimony may, however, be moderated by other factors, such as attitudes toward the death penalty (Ellsworth et al., 1984). We therefore, hypothesize that mock jurors' evaluations of expert testimony will be significantly associated with their attitudes toward the death penalty and the insanity defense.
In summary, while it may be reassuring to assume an accused person will be tried by an impartial jury, it must also be recognized that jurors bring attitudes, values, beliefs, and biases into the courtroom. How such attitudes and beliefs, in particular attitudes and beliefs toward the death penalty, relate to jurors' evaluation and selection of the insanity defense trial verdicts is again the major focus of this study.
Participants were exposed to a simulated insanity defense trial. The simulated trial, 90 minutes in length, was presented by means of audio tape and slide-projector. Following the reenacted trial, participants were asked to answer a series of questions regarding the case which were consistent with the theoretical and empirical issues that were introduced earlier.
One hundred thirty-seven undergraduate students at a southeastern university enrolled in introductory psychology classes served as participants for this study. The average age of participants was 19.4 years of age. Ninety-five percent of participants were White, 4% were Black, and 1% were other. Sixty-three percent of participants were women and 37% were men. Participants received course credit for their participation.
The present study used a simulated insanity defense trial with mock jurors. The mock-trial was dubbed onto an audio tape constructed with the assistance of judges, attorneys, and psychiatrists who showed a strong interest in this area of research. Once completed, the tape was played to public defenders to assess the realism of its contents and presentation.
In the mock-trial, State of Illinois v. John Carlton, the defendant John Carlton was charged with first degree stabbing death of the victim, Melissa Craft. Testimony revealed that John Carlton had been hospitalized for mental problems on two previous occasions, the first being a referral to the Illinois State Hospital on April 18, 1971, for a psychological evaluation. Referral was based upon his being arrested for assault and battery. While at the Illinois State Hospital, he was diagnosed as schizophrenic undifferentiated.
Participants were tested in small groups ranging in size from 14 to 20. The simulated trial was presented by means of an audio tape with accompanying slide-show, which lasted for approximately 90 minutes. Following the mock-trial, the participants completed a questionnaire. Participants were not allowed to discuss their opinions with any other participants, hence no group deliberations were held. Participants were physically spaced in the experimental room so that no participant was able to view another participant's responses.
Participants were asked, "Are you strongly in favor, somewhat in favor, somewhat opposed, or strongly opposed to the death penalty?" Based on their responses to this question, participants were classified into two groups: Those who favored the death penalty (strongly or somewhat, n = 100) and those who opposed the death penalty (strongly or somewhat, n = 37).
To measure their acceptance of the expert testimony, participants were asked four questions in the following format: "How reliable and true did you find the expert testimony of <name of the expert>, the <defense's/ prosecution's psychologist/psychiatrist>?" One item referred to the defense's psychologist, one to the defense's psychiatrist, one to the prosecution's psychologist, and one to the prosecution's psychiatrist. On each item the response scale was a 9-point scale from 1 (not valid at all) to 9 (fully valid). Participants' responses to the two questions about the expert testimony of the defense's psychologist and psychiatrist were averaged to produce the defense expert testimony variable, and the same was done to produce the prosecution expert testimony variable. On each of these variables higher scores indicate greater acceptance of the expert testimony.
To measure their assessment of the mental status of the defendant, each participant was asked five questions, each with a 9-point response scale. The questions were: a) "How confident are you that John Carlton's crime was not carried out under his own free will, and was instead the product of some mental disease or mental defect?" (1 = no confidence at all, 9 = full confidence); b) "How would you rate John Carlton's overall mental health status at the time of the crime?" (1 = he was completely well, 9 = he was completely sick); c) "To what degree do you believe that John Carlton's crime was a result of schizophrenia undifferentiated, as diagnosed by the defense group experts?" (1 = no belief at all, 9 = full belief); d) "To what degree do you believe that John Carlton's crime was the result of an antisocial personality disorder, as diagnosed by the prosecution experts?" (1 = no belief at all, 9 = total belief); and e) "To what degree do you believe that John Carlton was faking his disorder, as stated by one of the prosecution experts?" (1 = no belief, 9 = total belief).
To determine their attitudes about criminal liability and the insanity defense, participants were asked to what extent they agreed or disagreed with two statements: a) "People who commit antisocial acts should be punished, liable to criminal sanctions, regardless of their degree of mental disturbance," and b) "The insanity defense should be abolished from the courts." On these two questions the response options were "disagree strongly," "disagree somewhat," "agree somewhat," and "agree strongly." Based upon their responses to the questions about criminal liability and the insanity defense, we classified each participant as either agreeing or disagreeing with the statement that people who commit antisocial acts should be punished regardless of mental disturbance and as either favoring or opposing abolition of the insanity defense.
Each participant was also asked: "In the death of Melissa Craft, what is your verdict for the defendant John Carlton?"The response options were "guilty," "not guilty by reason of insanity," and "not guilty."
Finally, at the end of the survey, each participant was asked two questions taken from the Witherspoon Instruction. We note that prospective jurors whose attitudes toward the death penalty indicate an inability to be impartial in deciding guilt or innocence are excluded from capital trials (Witherspoon v. Illinois, 1968). The first question. which will hereafter referred to as the "impose" variable asked:
Is your attitude toward the death penalty such that as a juror you would never be willing to impose it in any case, no matter what the evidence, or would you consider voting to impose it at least in some cases?
The second question, which hereafter will be referred to as the "impartial" variable, asked participants to select either one of two responses, namely:
I would not follow the judge's instructions and decide the question of guilt or innocence in a fair and impartial manner based upon the evidence and the law, even if I knew that, if convicted he or she might receive the death penalty.
I would not follow the judge's instructions and decide the question of guilt or innocence in a fair and impartial manner based upon the evidence and the law, even if I knew that, if convicted, he or she might receive the death penalty. Witherspoon v. Illinois, 391 U.S. 510 (1968).
Our preliminary results showed that only 26 participants said they would never be willing to "impose" the death penalty. In addition, only I I participants stated that they could not be fair and "impartial" knowing that the defendant could be sentenced to death. As a result of this occurrence, we elected not to use the "impose" and "impartial" variables to define our death penalty attitude groups for our primary analyses because the very small sample sizes resulted in low statistical power.(n4) We elected to base our primary analyses on the question of whether one strongly or somewhat strongly favored the death penalty, n = 100, verses whether one was strongly or somewhat strongly opposed to the death penalty, n = 37.
However, we should note that for exploratory purposes we did look at the relationships between the "impose" and "impartial" Witherspoon items and our other variables. Both Witherspoon items "impose" and "impartial" were significantly correlated with our death penalty grouping variable (phi = .585 for the impose variable, .189 for the impartial variable). That is, there was a significantly higher proportion of Witherspoon-excludables within the group which strongly or somewhat opposed the death penalty than within the group which strongly or somewhat favored the death penalty. As shown in Tables I and 2, The "impose" and the "impartial" variables were correlated with the remaining variables in exactly the same directions as was our death penalty grouping variable, correlations which often fell short of statistical significance due, at least in part, to the low power resulting from small and very unbalanced sample sizes.
Compared to those who said they were unwilling to impose the death penalty in any case, mock jurors who were willing to consider imposing the death penalty were significantly more likely to favor abolishing the insanity defense (40% vs. 19%), Chi[sup 2](1, N = 136) = 3.94, p < .05; significantly more likely to agree that people who commit antisocial acts should be punished regardless (71% vs. 38%), Chi[sup 2] (1, N = 135) = 9.49, p < .01; and significantly more likely to vote guilty (65% vs. 42%), Chi[sup 2] (1, N = 136) = 4.34, p < .04.
Mock jurors who said they would be fair and impartial did not differ significantly on any of the variables from mock jurors who said they would not be fair and impartial. No statistically significant differences were found between the two groups with regards to abolishment of the insanity defense (37% vs.36%), Chi[sup 2] (1, N = 136) = .00, p = .98; agreement that people who commit antisocial acts should be punished regardless (66% vs. 45%), Chi[sup 2] (1, N = 135) = 1.89, p = .17; or frequency of guilty votes (62% vs. 55%), Chi[sup 2] (1, N = 136) = .21, p = .65.
Juror Attitudes and Verdict Selections
One of the primary questions featured in the present study was whether or not mock jurors' attitudes toward the death penalty would affect their evaluation and selection of an insanity defense verdict selection. Data from the present study clearly show mock jurors who favored the death penalty were significantly more likely to find the defendant guilty (67% guilty, 33% not guilty by reason of insanity) than were participants who opposed the death penalty (43% guilty, 57% not guilty by reason of insanity), Chi[sup 2] (1, N = 137) = 6.38, p < .02.
A discriminant function analysis was used to determine whether the mock jurors' attitudes toward the death penalty were associated with their assessments of the expert testimony, their assessments of the mental status of the defendant, their attitudes about criminal liability and the insanity defense, and their verdicts. A .05 criterion of statistical significance was employed here and elsewhere. The discriminant function was significant, F(10, 123) = 2.52, p < .01. With the exception of the defense expert testimony variable, all of the variables loaded well (>. 4) on the discriminant function (see Table 3). High scores on the discriminant function were associated with favoring the death penalty-the group centroid was .28 for those favoring the death penalty, -.73 for those opposed to the death penalty.
We also used logistic regression and standard multiple regression to predict attitude toward the death penalty from the same variables used in the discriminant function analysis. The results of these analyses were concordant with those of the discriminant function analysis: The statistical models were significant, with favoring the death penalty being best associated with the attitude that antisocial acts should be punished regardless of mental disturbance.
Univariate analyses and descriptive statistics were employed to help describe the significant discriminant function. As shown in Table 4, those who favored the death penalty were significantly more accepting of the prosecution's expert testimony than were those who opposed the death penalty, t(135) = 3.14, p < .01, but the two groups did not differ significantly on the acceptance of the defense's expert testimony, t(135) = .75, p=.46.
The death penalty groups differed significantly on each of the variables involving assessment of the mental status of the defendant. As shown in Table 4, participants who favored the death penalty had less confidence that the crime was the product of mental disease rather than free will, t(135) = 2.12, p =.04, rated the defendant as less mentally ill, t(133) = 2.04, p = .04, were less believing that the crime was the result of schizophrenia, t (134) = 2.23, p = .03, were more believing that the crime was the result of an antisocial personality disorder, t(134) = 2.42, p = .02, and were more believing that the defendant was faking his disorder, t(135) = 2.25, p = .03. The differences in df across these tests are due to missing data from a few participants in the group which favored the death penalty.
Attitudes toward the death penalty may be expected to be associated with attitudes about criminal liability and the insanity defense. Seventy-five percent of those who favored the death penalty agreed that people who commit antisocial acts should be punished regardless, significantly more than the 38% agreement among those opposed to the death penalty, Chi[sup 2] (1, N = 136) = 16.07, p < .001. Forty-three percent of those who favored the death penalty also favored the abolition of the insanity defense, significantly more than the 19% among those opposed to the death penalty, Chi[sup 2] (1, = 137) = 6.76, p < .01.
The present study was designed to assess the relationship between mock jurors' attitudes toward the death penalty and their insanity defense verdicts. Before examining the relationship between jurors' death penalty attitudes and their verdicts, we sought to determine first whether a significant relationship existed between mock jurors' attitudes toward the death penalty and their attitudes toward the insanity defense itself'. The analyses showed that those who favored the death penalty were also more favorable about abolishing the insanity defense. Also, those who favored the death penalty held the opinion that the insanity defense should not be allowed as a complete defense to a criminal charge. These findings are consistent with previous research (Ellsworth et al., 1984; Goldberg, 1970; Roberts & Golding, 1991) which show that those who favor the death penalty are less likely to show a favorable attitude toward the insanity defense.
Additional analyses were done on relevant criminal liability variables. These analyses reflected that those who favored the death penalty believed, as far as socially deviant behavior is concerned, that a person with a mental illness, regardless of its severity, is as blameworthy as a person without a mental illness. These findings are quite supportive of previous research findings (e.g., Cowan et al., 1984; Ellsworth et al., 1984; Poulson, 1988; Roberts & Golding, 1991; Thompson et al., 1984) which show that death penalty attitudes are significantly related to mock juror evaluation of criminal liability.
Given these particular findings, we further inquired whether mock jurors' attitudes toward the death penalty would influence their evaluation and selection of an actual verdict. Our data, like those reported by Ellsworth et al. (1984) and Goldberg (1970), show that jurors who favored the death penalty rendered a verdict of guilty significantly more than jurors who were opposed to the death penalty.
Evaluation of the Defendant's Mental Status
Data from the present study revealed that a positive attitude toward capital punishment was significantly related to a more positive attitude in the belief that the defendant was acting under his own free will. Furthermore, those who favored the death penalty reflected a greater belief that the defendant suffered from an antisocial personality disorder and that the defendant was faking his disorder.
These results strongly support findings reported by Luginbuhl and Middendorf (1988), who found that mock jurors who were not death penalty qualified (i.e., Witherspoon-excludables) were significantly more receptive to the "mitigating" factors in a capital case than were death qualified jurors. Data shown in the present study also support the conclusion reached by Thompson et al. (1984), who reported that death qualified jurors were significantly more likely to evaluate evidence in a manner consistent with the prosecution.
Expert Psychological Testimony
As hypothesized and indicated by the data, mock jurors attitudes toward the death penalty were significantly related to their assessments of expert diagnoses. Those who favored the death penalty were significantly more agreeable to the diagnoses given by the prosecution's expert witnesses. This finding is consistent with the notion that those who favor the death penalty are, in general, less willing to accept expert testimony which favors the defendant. Again, our data, like those of Thompson et al. (1984) and Luginbuhl and Middendorf (1988), show that death qualified jurors are significantly less receptive to (i.e., mitigate) the validity of expert testimony as presented by the defense group experts which, in turn, increases the likelihood of their returning a guilty verdict.
Psycho legal Implications
Based on the previous research findings and results shown in the present study, we question whether the "Witherspoon Instruction" is the most viable tool for assessing jurors' death penalty attitudes. For example, although very few of the mock jurors in the present study were classified as "Witherspoon-excludables," their attitudes measured in terms of sheer favorableness did have a strong influence on their verdict selections.
The most obvious question now becomes: Why was a significant effect observed for this particular death penalty attitude measure, and not for the "Witherspoon" measures? One possible explanation is that majority of participants in the present study, as appears true with many of the mock jurors featured in past research, actually believe they would be fair and impartial in deciding a case--even if they knew the defendant could receive the death penalty--or, that they would be willing to impose the death penalty in some cases.
When a person commits a capital offense and pleads insanity, he or she may be at a very distinct disadvantage. Those who favor the death penalty are less likely to believe in the value of an insanity defense; less likely to believe that the defendant's mental status warrants a not guilty finding; and are less likely to believe the expert witnesses of the defense group as compared to the prosecution's witnesses. Simply stated, those who favor the death penalty evaluate trial information in a manner that is quite distinct from those who oppose the death penalty. These differences in mock jurors' evaluative processes appear to manifest themselves in their actual verdict selections.
Authors' Notes: This research was made possible in part by a grant from the National Science Foundation (#A 11-9012742) awarded to Ronald L. Poulson. We would also like to thank Reid Hastie, Judy Cantor, Frank Dane, and Robert Boorman for their insightful comments and help with earlier drafts of this manuscript. We would also like to thank Marion Eppler for her editorial comments.
(n1) In the present study, jurors who respond to voir dire questioning, which includes the Witherspoon Instruction, in a manner that indicates an inability to be impartial in deciding guilt or innocence are referred to as "Witherspoon-excludables." Whereas, jurors who respond to this questioning in a manner that indicates an ability to be impartial in deciding guilt or innocence are referred to as "Witherspoon-includables."
(n2) A detailed description of the stimulus materials trial description and procedure can be obtained from the first author or by referencing Poulson, R.L., Braithwaite, R.L., Brondino, M.J, & Wuensch, K.L. (1997). Factors which discriminate among mock jurors' insanity defense verdict selections: The role of evidence, attitudes, and verdict options. Journal of Social Behavior and Personality. Or, it can be referenced from: Poulson, R.L. (1990). Mock juror attribution of criminal responsibility: Effects of race and the guilty but mentally ill (GMBI) verdict option. Journal of Applied Social Psychology, 20, 1596-161 1. These however are not the same data nor are they the same participants which were used in the Poulson et al. (1997) article; and, the dependent measures are different from the measures shown in the previously referred to studies.
(n3) We elected to use the Witherspoon Instruction due to the fact that a more recent decision (Wainwright v. Witt, 1985) was believed to make it easier for the State to exclude those jurors who were opposed to the death penalty. As indicated by Balske (1985), the "Substantial Impairment" standard would, in all likelihood, increase the number of jurors who are excluded for cause due to their opposition to the death penalty. For research purposes we did not want to reduce the number of people who were excludable above and beyond what was expected with the Witherspoon Instruction.
(n4) Virtually all of the research (Ellsworth et al., 1984; Poulson, 1988; Roberts & Golding, 1991) done in this area show relatively low percentages of participants who are death penalty excludable as based upon the Witherspoon Instruction. One tentative explanation for this occurence is that the demand characteristics of the courtroom or simulated courtroom situations may overwhelmingly encourage jurors to respond in a manner which is thought to be unbiased.
Group Mean (SD) Would Not would Consider Consider Imposing Death Imposing Variable Penalty Death Penalty Evaluation of expert testimony Prosecution's expert testimony 5.93 (1.81) 5.23 (2.21) Defense's expert testimony 5.37 (2.06) 5.69 (2.21) Assessment of mental status Crime due to mental illness 4.37 (2.75) 5.04 (2.90) Defendant mentally ill 4.97 (2.48) 5.92 (2.45) [*] Crime resulted from schizophrenia 4.17 (2.77) 5.46 (2.80) [*] Resulted from antisocial personality 5.94 (2.48) 4.77 (2.57) Defendant faking his disorder 5.50 (2.63) 4.65 (2.65) Note: The groups differed significantly (p < .05) only on the two variables marked with asterisks.
Group Mean (SD) Would Be Would Not Be Variable Fair and Fair and Impartial Impartial Evaluation of expert testimony Prosecution's expert testimony 5.90 (1.83) 4.95 (2.56) Defense's expert testimony 5.35 (2.10) 6.06 (l.94) Assessment of mental status Crime due to mental illness 4.44 (2.75) 4.73 (3.23) Defendant mentally ill 5.07 (2.48) 5.64 (2.45) Crime resulted from schizophrenia 4.33 (2.78) 4.91 (2.80) Resulted from antisocial personality 5.83 (2.54) 4.73 (2.45) Defendant faking his disorder 5.45 (2.64) 4.64 (2.80) Note: The groups differed significantly (p < .05) on none of the variables.
Variable Loading Evaluation of expert testimony Prosecution's expert testimony .60 Defense's expert testimony -.12 Assessment of defendant's mental status Crime due to mental illness -.43 Defendant mentally ill -.41 Crime resulted from schizophrenia -.44 Crime resulted from antisocial disorder .47 Defendant faking his disorder .44 Attitudes Punish regardless of mental disturbance .80 Abolish the insanity defense .51 Verdict Guilty Verdict .49
Group Mean (SD) Favor Oppose Variable Death Penalty Death Penalty Evaluation of expert testimony Prosecution's expert testimony 6.12 (1.72) 5.00 (2.16) Defense's expert testimony 5.34 (2.08) 5.64 (2.10) Assessment of mental status Crime due to mental illness 4.18 (2.71) 5.30 (2.38) Defendant mentally ill 4.87 (2.49) 5.84 (2.41) Crime resulted from schizophrenia 4.08 (2.76) 5.27 (2.80) Resulted from antisocial disorder 6.05 (2.51) 4.89 (2.44) Defendant faking his disorder 5.67 (2.59) 4.54 (2.66) Note: The groups differed significantly (p < .05) on every variable except for the defense expert testimony variable.
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By Ronald L. Poulson, Karl L. Wuensch and Michael B. Brown, Department of Psychology, East Carolina University, 311 Rawl Building, Greenville, NC 27858-4353 and Ronald L. Braithwaite, School of Public Health, Emory University, Atlanta, GA 30322
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