The United States Supreme Court’s 1993 Daubert v. Merrell Dow Pharmaceuticals case established criteria for admitting scientific evidence in federal courts. It holds that scientific evidence must be valid, reliable, and relevant, and judges are required to be “gatekeepers” of evidence by screening out evidence that has not been empirically tested or vetted through the academic community. Yet, little is known about whether psychological assessment tools are subjected to scrutiny through the standards courts are supposed to apply. In three different studies, from the perspectives of judges, attorneys, and forensic mental health experts, the authors investigate whether psychological assessment evidence is being challenged. Information was collected on participants’ experiences with challenges to psychological assessments. Judges and lawyers completed a series of experimental case vignettes to assess their decision-making about legal admissibility of different qualities of psychological assessments. It was hypothesized they would not distinguish between low- and high-quality psychological assessments in admissibility. Bayesian model selection methods did not support the null hypothesis, however. It was found attorneys differentiate between the conditions. The rates in which legal professionals and forensic mental health evaluators experienced challenges were also higher than was expected. These positive findings show there is some degree of gatekeeping psychological assessment evidence in the courts.

Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification—highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications—highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence.

Research at the intersection of psychology and law has demonstrated that juror decision-making is subject to many cognitive biases, however, it fails to consider the influence of culturally derived cognitive biases. As jurors become increasingly demographically and culturally diverse it is possible—and even likely—that their attributions might vary because of their cultural background. I predict that cultural and demographic group affiliation affects attributional tendencies such that, compared to situationally focused individuals (those from East Asian cultures, women, those from lower socioeconomic status groups, and older individuals), dispositionally focused individuals (those from Western cultures, men, those from higher socioeconomic status groups, and younger individuals) are less likely to attribute some portion of causation and responsibility for the harm to other influences, and they are more likely to find the defendant liable and hold the defendant financially responsible to a greater degree. This dissertation has three aims: (1) to examine how culturally derived attributional tendencies influence jurors' assessments of causation in complex negligent tort cases where there are multiple causal influences (i.e., multiple tortfeasors and plaintiff negligence) (Studies 1 and 2); (2) to study the implications of those causal determinations on liability determinations, damage awards, and other legal decisions (Studies 1 and 2); and (3) to determine whether these culturally derived attributional tendencies are malleable, suggesting an intervention that might be used to attenuate the influence of attributional tendencies in a trial setting (Study 3). This work advances psychological research on cultural differences in attribution by exploring attributional differences in a new domain, developing a new scale of individual differences in attributional tendencies, and examining how multiple causal influences affects culturally derived attributional tendencies and downstream decision-making.

Recent advances in hierarchical or multilevel statistical models and causal inference using the potential outcomes framework hold tremendous promise for mock and real jury research. These advances enable researchers to explore how individual jurors can exert a bottom-up effect on the jury’s verdict and how case-level features can exert a top-down effect on a juror’s perception of the parties at trial. This dissertation explains and then applies these technical advances to a pre-existing mock jury dataset to provide worked examples in an effort to spur the adoption of these techniques. In particular, the paper introduces two new cross-level mediated effects and then describes how to conduct ecological validity tests with these mediated effects. The first cross-level mediated effect, the a1b1 mediated effect, is the juror level mediated effect for a jury level manipulation. The second cross-level mediated effect, the a2bc mediated effect, is the unique contextual effect that being in a jury has on the individual the juror. When a mock jury study includes a deliberation versus non-deliberation manipulation, the a1b1 can be compared for the two conditions, enabling a general test of ecological validity. If deliberating in a group generally influences the individual, then the two indirect effects should be significantly different. The a2bc can also be interpreted as a specific test of how much changes in jury level means of this specific mediator effect juror level decision-making.

Life History Theory suggests that, in order to maximize reproductive fitness, individuals make trade-offs between allocating resources to mating and parenting. These trade-offs are influenced by an individual's sex, life history strategy, and environment. Here, I explored the usefulness of a Life History Theory framework for understanding endorsement of child support laws. This study experimentally manipulated sex ratio, and gathered information about participants' endorsement of child support, sexual restrictedness, and mate value. As predicted, women endorsed child support more than men, whereas men favored greater restriction of child support in the form of required paternity testing. However, in general, results do not support an effect of sex ratio, sexual restrictedness, or mate value on endorsement of child support. Results suggest sensitivity to exploitation in a male-biased sex ratio, reflected by an increase in men's endorsement of paternity testing requirements under a male-biased sex ratio prime. Women, on the other hand, report especially unfavorable beliefs toward paternity testing in a male-biased sex ratio. Although results of the current study are mixed, there remains much to be gained from applying an evolutionary perspective to understanding variability in endorsement of child support.

Psychology of justice research has demonstrated that individuals are concerned with both the process and the outcomes of a decision-making event. While the literature has demonstrated the importance of formal and informal aspects of procedural justice and the relevancy of moral values, the present study focuses on introducing a new form of justice: Substantive justice. Substantive justice focuses on how the legal system uses laws to constrain and direct human behavior, specifically focusing on the function and the structure of a law. The psychology of justice literature is missing the vital distinction between laws whose function is to create social opportunities versus threats and between laws structured concretely versus abstractly. In the present experiment, we found that participant evaluations of the fairness of the law, the outcome, and the decision-maker all varied depending on the function and structure of the law used as well as the outcome produced. Specifically, when considering adverse outcomes, individuals perceived laws whose function is to create liability (threats) as being fairer when structured as standards (abstract guidelines) rather than rules (concrete guidelines); however, the opposite is true when considering laws whose function is to create eligibility (opportunities). In juxtaposition, when receiving a favorable outcome, individuals perceived laws whose function is to create liability (threats) as being fairer when defined as rules (concrete guidelines) rather than standards (abstract guidelines).