Nature,nurture, and capital punishment: How evidence of a genetic–environment interaction,future dangerousness,and deliberation affect sentencing decisions

Research has shown that the low‐activity MAOA genotype in conjunction with a history of childhood maltreatment increases the likelihood of violent behaviors. This genetic–environment (G × E) interaction has been introduced as mitigation during the sentencing phase of capital trials, yet there is scant data on its effectiveness. This study addressed that issue. In a factorial design that varied mitigating evidence offered by the defense [environmental (i.e., childhood maltreatment), genetic, G × E, or none] and the likelihood of the defendant's future dangerousness (low or high), 600 mock jurors read sentencing phase evidence in a capital murder trial, rendered individual verdicts, and half deliberated as members of a jury to decide a sentence of death or life imprisonment. The G × E evidence had little mitigating effect on sentencing preferences: participants who received the G × E evidence were no less likely to sentence the defendant to death than those who received evidence of childhood maltreatment or a control group that received neither genetic nor maltreatment evidence. Participants with evidence of a G × E interaction were more likely to sentence the defendant to death when there was a high risk of future dangerousness than when there was a low risk. Sentencing preferences were more lenient after deliberation than before. We discuss limitations and future directions.     

Juror Decision‐making in Death Penalty Sentencing when Presented with Defendant's History of Child Abuse or Neglect

Previous studies have found aggravating, mitigating, and null effects of defendant histories of abuse and neglect on punishment preferences in capital sentencing. Perceiving these defendants as more dangerous, jurors may be more likely to favor the death penalty when such evidence is presented. This is counter to the intuition that abuse or neglect reduces culpability, and therefore mitigates the severity of punishment. We investigated the effect of defendant childhood physical abuse, sexual abuse, or neglect on the probability of a prospective juror preferring the death penalty in an between‐subject experimental design. Using vignettes and two large samples (students and jurors), defendant histories were found to mitigate the probability that the hypothetical defendant received the death penalty, with sexual abuse having the most salient effect. Further, the effects were conditioned by preference for the death penalty – larger mitigating effects were observed among individuals who favor the death penalty. These findings suggest that initial judgments of abuse and neglect are related to juror leniency, and further research on the interaction of jury instructions and defendant histories is needed. Copyright © 2017 John Wiley & Sons, Ltd.     

Effects of neuroimaging evidence on mock juror decision making

During the penalty phase of capital trials, defendants may introduce mitigating evidence that argues for a punishment "less than death." In the past few years, a novel form of mitigating evidence-brain scans made possible by technological advances in neuroscience-has been proffered by defendants to support claims that brain abnormalities reduce their culpability. This exploratory study assessed the impact of neuroscience evidence on mock jurors' sentencing recommendations and impressions of a capital defendant. Using actual case facts, we manipulated diagnostic evidence presented by the defense (psychosis diagnosis; diagnosis and neuropsychological test results; or diagnosis, test results, and neuroimages) and future dangerousness evidence presented by the prosecution (low or high risk). Recommendations for death sentences were affected by the neuropsychological and neuroimaging evidence: defendants deemed at high risk for future dangerousness were less likely to be sentenced to death when jurors had this evidence than when they did not. Neuropsychological and neuroimaging evidence also had mitigating effects on impressions of the defendant. We describe study limitations and pose questions for further research.     

Negative Emotions Felt During Trial: the Effect of Fear,Anger, and Sadness on Juror Decision Making

During trial, jurors may experience a variety of emotions, many of which are negative. The current study examined the effects the negative emotions anger, fear, and sadness had on jurors' sentencing decisions and explored whether the cognitive appraisal theory or the intuitive prosecutor model could explain these effects. Jurors viewed the sentencing phase of a capital murder trial and were asked to sentence the defendant. Results indicated that after viewing the trial, jurors reported increased anger and sadness, but not fear. However, only change in anger affected jurors' sentences. Jurors who reported a greater change in anger were more likely to sentence the defendant to death. This effect was mediated by the level of importance that jurors placed on the prosecution's evidence and argument. Consistent with the intuitive prosecutor model, increased anger led to higher ratings of the importance of the aggravating evidence and an increase in death sentences. Implications are discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Arbitrariness and the death penalty: how the defendant's appearance during trial influences capital jurors' punishment decision

This paper examines the impact of the defendant's appearance during the trial on capital jurors' punishment decision. The data used in this analysis were gathered by the Capital Jury Project (CJP), a national program of research on the decision-making of capital jurors. A series of multivariate logistic regression analyses were conducted using four aggravating circumstances related to the killing and eight defendant appearance variables as predictors of jurors' punishment decision at three points during the capital trial: (1) after the punishment phase ended, but before formal deliberation began; (2) when the first vote was taken on punishment at jury deliberations; and (3) at the final vote on punishment. Results indicated that when the defendant appeared emotionally involved during the trial (i.e. sorry and sincere) jurors either favored a life sentence or were undecided about punishment; however, when the defendant appeared emotionally uninvolved during the trial (i.e. bored) jurors either sought a death sentence or remained undecided. Policy implications will be discussed.     

The Influence of Biomedical Information and Childhood History on Sentencing

A recent trend in court is for defense attorneys to introduce brain scans and other forms of biomedical information (BI) into criminal trials as mitigating evidence. The present study investigates how BI, when considered in combination with a defendant's childhood information (CI), can influence the length of a defendant's sentence. We hypothesized that certain combinations of BI and CI result in shorter sentences because they suggest that the defendant poses less of a threat to society. Participants were asked to read accounts of the trial of a murder suspect and, based on the information therein, recommend a sentence as if they were the judge. The defendant was diagnosed with psychopathy, but biomedical information regarding that diagnosis was included or excluded depending on the BI condition. The defendant was further described as growing up in either a loving or abusive family. The results showed that, if BI was present in the trial account, the defendant from an abusive family was perceived as less of a threat to society and received a shorter recommended sentence than if the defendant had been from a loving family. If BI was absent from the account, the pattern was reversed: the defendant from a loving family was perceived as less of a threat to society and received a shorter recommended sentence than if he had been from an abusive family. Implications for the use of BI and CI in court trials are discussed, as well as their relationship to free will and the function of punishment as retribution and utility. Copyright © 2015 John Wiley & Sons, Ltd.     

Psychopathic traits predict attitudes toward a juvenile capital murderer

The current study manipulated the presence/:absence of psychopathic traits and the ethnicity (Black/:White) of a juvenile capital murderer to examine their impact on layperson attitudes regarding what types of legal sanction were appropriate. Participants (N=360) reviewed a newspaper article concerning a death row inmate who was appealing his sentence primarily based on the fact that he committed the crime when he was 16 years of age. Compared to those in the control condition, those who read a scenario in which the defendant had been described at trial as exhibiting psychopathic traits (e.g. remorselessness, pathological lying) were significantly more likely to support a death sentence and less likely to believe he should receive any treatment in prison. Moreover, participant ratings of the extent to which they believed the defendant exhibited prototypically psychopathic traits (regardless of whether they were in the psychopathy or control condition) also significantly predicted these criterion measures. Ethnic status was relatively less influential, although participants were somewhat more punitive towards a Black defendant than a White defendant when considering the relevance of possible mitigating factors (e.g. history of sexual abuse).     

The Effects of Race and Social Dominance Orientation in Simulated Juror Decision Making1

Recent mock‐jury research often has found no evidence that White jurors are more likely to convict and impose harsher sentences on Black compared to White defendants. Drawing on social dominance theory (Sidanius & Pratto, 1999), this paper argues that this apparent null effect reflects that different racial biases shown by White jurors varying in social dominance orientation (SDO) cancel each other out. A mock‐jury study (n= 70) found no main effect for defendant race, but evidence for a crossover interaction with high SDO individuals showing an anti‐Black bias and with low SDO individuals showing a pro‐Black bias in their guilty judgments and sentence recommendations. The discussion argues race is still a critical factor in White jurors’ decision making.     

Reducing racial bias in the penalty phase of capital trials

Past research (e.g. Lynch & Haney, 2000) has shown that race plays a significant role in juror decision making in the penalty phase of capital murder trials. This study investigates the possibility of reducing juror bias towards Blacks by altering the content of jury instructions. White and non-White participants received trial information and jury instructions in which the defendant's race (Black or White) and the instruction type (standard or simplified) were manipulated. Participants rendered a sentence recommendation, identified factors they considered to be aggravating or mitigating, and responded to instruction comprehension questions. Bias against the Black defendant was significantly reduced when simplified instructions were used and when the defendant was judged by racially diverse jurors. Simplification also led to better comprehension of sentencing instructions. Implications for capital trials are discussed.     

Attractive but guilty: deliberation and the physical attractiveness bias

The current study examined the effect of jury deliberation on the tendency for mock jurors to find attractive defendants guilty less often. It was expected that there would be an interaction between group deliberation (yes or no) and defendant's appearance (plain-looking or attractive). It was hypothesized that mock jurors who did not deliberate would be more likely to find a plain-looking defendant guilty and that deliberation would mitigate this effect. The study was a 2 x 2 between-subjects factorial design. Participants were assigned randomly to one of four conditions: attractive defendant/deliberation, attractive defendant/no deliberation, plain-looking defendant/deliberation, and plain-looking defendant/no deliberation. A total of 172 undergraduates from a small, rural college in Vermont contributed to this study: mock jurors were 70 men and 52 women, ages ranged from 18 to 52 years (M=20.5, SD=4.9). The hypothesis was supported. Mock jurors who did not deliberate were more likely to find the plain-looking defendant guilty, whereas mock jurors who deliberated were more likely to find the attractive defendant guilty.     

How jurors use and misuse character evidence

The Federal Rules of Evidence allow defendants to offer testimony about their good character, but that testimony can be impeached with cross-examination or a rebuttal witness. It is assumed that jurors use the defense's character evidence (CE) to form guilt and conviction judgments but use impeachment evidence only to assess the character witness's credibility. Two experiments tested these assumptions by presenting mock jurors with various forms of CE and impeachment. Participants made trait ratings for the character witness and defendant and guilt and conviction judgments. Positive CE did not affect guilt or conviction judgments, but cross-examination caused a backlash in which judgments were harsher than when no CE was given. Using path analysis, the authors tested a model of the process by which CE and impeachment affect defendant and witness impressions and guilt and conviction judgments. Implications for juror decision making are discussed.     

How type of excuse defense, mock juror age, and defendant age affect mock jurors' decisions

The authors investigated the effects of mock juror age (younger vs. older), defendant age (22 vs. 65), and type of excuse defense used by defendants (a highly self-inflicted condition, Cocaine Dependency Disorder, vs. a less self-inflicted condition, Posttraumatic Stress Disorder) on mock juror decisions. Ninety-six younger and 96 older adults read a scenario and answered a questionnaire. Results indicated that the defendant using the highly self-inflicted excuse was more likely to receive a guilty verdict and a longer sentence than was the defendant using the less self-inflicted excuse. Older jurors were more certain of their verdicts and saw the defendant as more responsible for his condition than did younger jurors. Defendant age did not affect juror decisions. In addition, excuse type and juror age affected the jurors' perceptions of the victim's responsibility for the attack. The authors discuss the potential influence of juror age on perceptions of defendant responsibility.     

Will jurors correct for evidence interdependence in their verdicts? It depends

Throughout an investigation, pieces of evidence are likely to contaminate one another, yet at trial jurors are expected to treat pieces of evidence as if they are independent. Are jurors able to understand potential evidence contamination? The present study showed mock jurors a videotaped trial simulation. Participants were randomly assigned to hear testimony regarding one piece of evidence, two pieces of independent evidence, or two pieces of interdependent evidence. The study tested the hypothesis that jurors who hear evidence that is interdependent will be just as likely to find the defendant guilty as jurors who hear about two pieces of independent evidence. When an eyewitness's identification was the uncontaminated piece of evidence, our hypothesis was supported. However, when the confession was the uncontaminated piece of evidence, jurors seemed to understand that one piece of evidence had been influenced by another and adjusted their beliefs about the defendant's guilt accordingly. This study supports the conclusion that jurors can sometimes identify and correct for evidence contamination in their perceptions of a defendant's guilt. Implications for reform support are discussed.     

Effects of physical attractiveness on evaluations of a male employee's allegation of sexual harassment by his female employer

College students (N = 324) served as mock jurors in a simulated civil case in which a male plaintiff accused a female defendant of sexual harassment. The authors experimentally manipulated the physical attractiveness of the litigants. The authors asked mock jurors to decide whether the defendant was guilty and to rate their certainty of belief in the defendant's guilt (or lack of guilt). Jurors were more certain of the guilt of the defendant when the plaintiff was attractive than when he was unattractive. Plaintiff attractiveness significantly affected female jurors' individual recommended verdicts when the defendant was unattractive but not when she was attractive. With male jurors, plaintiff attractiveness significantly affected their verdicts when the defendant was attractive but not when she was unattractive. Female jurors were more likely than male jurors to conclude that sexual harassment had taken place but only when the litigants were different in attractiveness.     

The Impact of Defendant Gender and Relationship to Victim on Juror Decisions in a Child Sexual Abuse Case

We examined the impact of defendant gender and relationship to victim on verdict decisions and ratings of witness believability in a case of alleged child sexual assault. Mock jurors ( N  = 256) read 1 of 4 extensive case summaries. The cases varied the gender of the defendant and his or her relationship to the child (parent or stranger). Data revealed that participants were significantly more likely to find male defendants (especially the father) guilty than female defendants. Female jurors rated the victim as more believable and the defendant as less believable than did male jurors. All mock jurors rated the victim as more believable if the defendant was male, and they saw the female defendants as more believable than the male defendants.     

Jurors' locus of control and defendants' attractiveness in death penalty sentencing

The authors examined the relationship between jurors' locus of control and defendants' attractiveness in death penalty sentencing. Ninety-eight participants voluntarily served as mock jurors. The authors administered J. B. Rotter's (1966) Internal-External Locus of Control Scale to participants and then randomly assigned them to a group with either an attractive or an unattractive defendant (represented by photographs). Participants read a murder vignette and selected a punishment--either a lifetime jail sentence or the death penalty-for the defendant. Results indicated that neither jurors' locus of control nor defendants' attractiveness influenced sentencing. However, jurors' age and gender significantly influenced sentencing. Men, with the exception of the youngest men, were more likely than women to choose the death penalty. Additionally, young women were more likely than older women to select the death penalty. The authors discuss the implications of these results for the study of jury behavior and bias.     

The effect of the psychopathy checklist – revised in capital cases: Mock jurors' responses to the label of psychopathy

Despite mixed empirical evidence regarding the ability of the Psychopathy Checklist – Revised (PCL‐R) to predict violence among incarcerated inmates, it continues to be used to address such questions, even in the context of capital cases. The purpose of this study was to examine if the PCL‐R has a prejudicial effect on mock jury members during the sentencing phase of a capital murder trial. Results indicated that participants were more likely to sentence the defendant to death when the defendant exhibited a high likelihood to commit future violence, whether or not the diagnostic label “psychopath” was present. Interestingly, when asked to rate the defendant's likelihood for future violence and murder, the defendant who was a high risk for future violence and not labeled a psychopath received the highest rating. These results suggest an absence of juror bias as it pertains to the label “psychopath” when sentencing a defendant in a capital murder case. Copyright © 2010 John Wiley & Sons, Ltd.     

Community members' perceptions of evidence: the effects of gender in a recovered memory civil trial.

Community members judged a civil trial in which a memory had either been recovered or kept secret until therapy 12 years later. Female jurors were more likely to find the defendant liable and to compensate female plaintiffs more than male plaintiffs, whereas the reverse pattern held for male jurors. Female plaintiffs who reported recovered memories were compensated least, whereas female plaintiffs who kept the abuse secret were compensated most. A mediational model was posited and results indicated that the origin of the memory of sexual abuse and victim gender influenced assessments of trial testimonies that were related to the trial outcomes. Results supported the postulated model and indicated significant juror-gender differences in evaluating and weighing the evidence.