It is heartening to see that our work (Wixted et al., 2019) has inspired so much commentary and that our critics—Sjerps (2019), Meester and Slooten (2019), and Neumann and Ausdemore (2019)—agree that base-rate neglect in the single-match DNA database search scenario is a potentially serious problem. We congratulate them for their thoughtful contributions. Here, we provide perspective on the critiques, showing how, if anything, they strengthen our argument in favour of reporting case-independent posterior odds. Our goal is to provide advice on the reporting of DNA evidence that will lead to just outcomes. Our claim is that when there is a single match in a database search, the case-independent posterior odds are a matter of forensic science without the need for legal judgment. The critiques fall into two distinct categories: technical critiques (provided by Meester and Slooten, 2019) and substantive critiques (provided by Neumann and Ausdemore, 2019; Sjerps, 2019). We address the technical ones first though we realize the points may be outside the interest of some readers. Those who are more interested in the substantive debate can read ahead without much loss.

As part of a criminal investigation, the police often administer a recognition memory task known as a photo lineup. A typical 6-person photo lineup consists of one suspect (who may or may not be guilty) and five physically similar foils (all known to be innocent). The photos can be shown simultaneously (i.e., all at once) or sequentially (i.e., one at a time). Approximately 30% of U.S. police departments have moved to using the sequential lineup procedure over the last 30 years, yet its theoretical underpinnings remain poorly understood. A simple signal detection model makes several unexpected predictions about how the sequential lineup procedure should affect the ability of eyewitnesses to discriminate innocent from guilty suspects. For example, empirical discriminability (area under the receiver operating characteristic) should decrease as the position of the suspect in the lineup increases. In addition, under some conditions, a fair sequential lineup should not yield higher discriminability than a single-person (non-lineup) recognition test known as a showup. The results of two experiments reported here confirmed these predictions. Counterintuitively, even though empirical discriminability decreased as the suspect's sequential position increased, a signal detection model fit to the data indicated that theoretical discriminability exhibited a small effect in the opposite direction (increasing with the sequential position of the suspect). The latter result is consistent with diagnostic feature-detection theory of eyewitness identification.

Forensic evidence is often quantified by statisticians in terms of a likelihood ratio. When the evidence consists of a DNA match, the likelihood ratio is equal to the reciprocal of the random match probability' (p). When p is small (e.g. 1/10 million), the likelihood ratio is large (e.g. 10 million to 1). However, when a single match is obtained by searching a database, the prior odds that the forensic DNA was deposited by the matcher can be extremely low, in which case the posterior odds can be low as well despite the high likelihood ratio. Unfortunately, prosecutors, judges and jurors are at risk of misinterpreting the likelihood ratio as the posterior odds, a pervasive reasoning error known as base-rate neglect. Here, we propose a solution to that problem, which consists of evaluating the prior odds based on a case-independent estimate of the size of the active criminal population derived from database search statistics. The posterior odds that the forensic DNA belongs to the unidentified single-matcher can then be calculated (avoiding base-rate neglect).

Performance measurement is considered useful in guiding donations to charities. We investigated whether efficiency rates predominately guide donations relative to available alternatives, or influence donation amounts. Across four studies ( N = 460), participants evaluating charity advertisements saw randomly assigned efficiency rates presented as background information. Participants could pledge a portion of a gift card, offered in return for participation, to their pick of presented charities. Participants were sensitive to relative, but not absolute, efficiency, giving more often to more relatively efficient charities but generally did not pledge them more money. Even providing an explicit standard of efficiency did not create an absolute sensitivity to efficiency, suggesting that efficiency information, steers, rather than encourages, or discourages, donations overall.

Cognitive psychologists are familiar with how their expertise in understanding human perception, memory, and decision-making is applicable to the justice system. They may be less familiar with how their expertise in statistical decision-making and their comfort working in noisy real-world environments is just as applicable. Here we show how this expertise in ideal-observer models may be leveraged to calculate the probability of guilt of Gary Leiterman, a man convicted of murder on the basis of DNA evidence. We show by common probability theory that Leiterman is likely a victim of a tragic contamination event rather than a murderer. Making any calculation of the probability of guilt necessarily relies on subjective assumptions. The conclusion about Leiterman's innocence is not overly sensitive to the assumptions-the probability of innocence remains high for a wide range of reasonable assumptions. We note that cognitive psychologists may be well suited to make these calculations because as working scientists they may be comfortable with the role a reasonable degree of subjectivity plays in analysis.

There is a vast literature that seeks to uncover features underlying moral judgment by eliciting reactions to hypothetical scenarios such as trolley problems. These thought experiments assume that participants accept the outcomes stipulated in the scenarios. Across seven studies (N = 968), we demonstrate that intuition overrides stipulated outcomes even when participants are explicitly told that an action will result in a particular outcome. Participants instead substitute their own estimates of the probability of outcomes for stipulated outcomes, and these probability estimates in turn influence moral judgments. Our findings demonstrate that intuitive likelihoods are one critical factor in moral judgment, one that is not suspended even in moral dilemmas that explicitly stipulate outcomes. Features thought to underlie moral reasoning, such as intention, may operate, in part, by affecting the intuitive likelihood of outcomes, and, problematically, moral differences between scenarios may be confounded with non-moral intuitive probabilities.

Holding an incremental, rather than fixed, mindset confers wide-ranging benefits. Such benefits may, however, be accompanied by increased judgmental harshness of others' shortcomings. Across 3 studies (Studies 1, 2a, 2b; N = 416), after an induction of either an entity or incremental view of empathy, aggression, or motivation, participants were asked to imagine someone continually failing to show, or showing in abundance, the particular trait, and were then asked how blameworthy/praiseworthy each of these individuals was. Incremental-induced participants blamed a person showing consistently maladaptive levels of the trait more than did entity-induced participants. Increased blame was mediated by increased perceived control over behavior. Study 3 (N = 107) extended findings regarding lay theories of empathy to protagonists in short narratives. Study 4 (N = 184) attempted to reconcile our findings with previous research, showing that increased blame attribution by incremental theorists occurs for continual, but not single failures. Overall results suggest that the benefits of an incremental mindset may be partially offset by greater judgmental harshness of others.

Social essentialismthe belief that individuals contain an underlying essence determined by the social categories they belong tohas generally been regarded as a harmful cognitive process that results in prejudice and other forms of injustice at the group level. Trait essentialism, also termed a fixed mindsetthe belief that people's trait levels are determined and relatively unchangeablehas been construed as a parallel impediment to self-improvement at the individual level. However, each of these domains contains findings that do not fit this narrative, suggesting that such essentialized thinking is not always detrimental at either the group or individual level and that its effects may instead depend on motivation and context. Incorporating advances in research on moral judgment and identity allow for a reconciliation of the variable effects of social and trait essentialism. In some instances, essentialism can be a strategy for reducing blame over uncontrollable aspects of individuals and groups and for identity formation.

Desire spurs competition; here we explore whether the converse is also true. In one study, female quartets (N = 58) completed anagrams, with the winner to receive compact speakers; controls anagrammed without competition. In the other study, female quartets (N = 74) described their ideal first date to a male judge, who chose the best description; controls read to him others' date descriptions without competition. In both studies, creating competition increased desire and altered how much participants wanted, but not how much they liked, the competed-for thing. Competition may activate a general “wanting system,” producing overvaluing in settings from stock markets to partner selection.

Recognizing the reasonableness of others' positions is important for conflict reduction, but is notoriously hard. We tested a perspective-taking approach to decreasing attitude entrenchment. Participants were held accountable in a task in which they wrote about a controversial issue from the perspective of a partner with an opposing viewpoint. This approach was effective at changing views on controversial issues—in Study 1 on weight discrimination, an issue participants were unlikely to have thought much about, and in Study 2 on abortion, where beliefs tend to be more deeply held. Studies 3 and 4 showed this change only took place under conditions where participants met the individual with an opposing view in person, and where that individual would see the perspective-taking effort. These results suggest that it is possible to reduce attitude entrenchment by encouraging people to think about the opposing perspective of another, as long as there is real contact and accountability.

People find it important to know if a story is factual, but still the most popular stories, in such forms as books and movies, are fictional. Research suggests that a story being true may add value to the reader’s experience, but other findings suggest that fiction may increase enjoyment by providing fewer disruptions to narrative comprehension. In three studies we explored the appeal of stories when they are presented as fiction or as non-fiction. Subjects read (1) story synopses, (2) vignettes from two popular websites, or (3) narratives on relationships and war. Results indicate that readers preferred stories when they were presented, externally, as non-fiction. Readers also preferred stories that seemed internally — that is, because of how they were written — like fiction. Additionally the results suggested that readers rely more heavily on factual stories to update their notions of reality. This study contributes to a body of literature on reader enjoyment in relation to truth labels made explicit or implicit in narratives as well as on the efficacy of arts-based research.

Online social networking is vastly popular and permits its members to post their thoughts as microblogs, an opportunity that people exploit, on Facebook alone, over 30 million times an hour. Such trivial ephemera, one might think, should vanish quickly from memory; conversely, they may comprise the sort of information that our memories are tuned to recognize, if that which we readily generate, we also readily store. In the first two experiments, participants' memory for Facebook posts was found to be strikingly stronger than their memory for human faces or sentences from books-a magnitude comparable to the difference in memory strength between amnesics and healthy controls. The second experiment suggested that this difference is not due to Facebook posts spontaneously generating social elaboration, because memory for posts is enhanced as much by adding social elaboration as is memory for book sentences. Our final experiment, using headlines, sentences, and reader comments from articles, suggested that the remarkable memory for microblogs is also not due to their completeness or simply their topic, but may be a more general phenomenon of their being the largely spontaneous and natural emanations of the human mind.

Spoilers, despite their name, seem to increase enjoyment of stories. This could be because readers enjoy reading expected endings, because knowing the ending allows them to appreciate aesthetic elements instead of guessing what will happen, or because knowing the ending increases fluency by enabling readers to correctly interpret clues and events. We conducted three experiments to test these hypotheses. Experiment 1 collected ratings at the midpoints of anthologized stories, and determined that readers experience greater pleasure even before reading the end of spoiled stories. This spoiler benefit was mediated by processing fluency, and not by appreciation of aesthetic elements. Experiment 2 found that spoilers similar to those in Experiment 1 do not increase ease of reading — or pleasure — for very-easy-to-read stories. Experiment 3 found, however, that very simple spoilers could increase the pleasure of easy-to-read stories.

Spoilers, despite their name, seem to increase enjoyment of stories. This could be because readers enjoy reading expected endings, because knowing the ending allows them to appreciate aesthetic elements instead of guessing what will happen, or because knowing the ending increases fluency by enabling readers to correctly interpret clues and events. We conducted three experiments to test these hypotheses. Experiment 1 collected ratings at the midpoints of anthologized stories, and determined that readers experience greater pleasure even before reading the end of spoiled stories. This spoiler benefit was mediated by processing fluency, and not by appreciation of aesthetic elements. Experiment 2 found that spoilers similar to those in Experiment 1 do not increase ease of reading — or pleasure — for very-easy-to-read stories. Experiment 3 found, however, that very simple spoilers could increase the pleasure of easy-to-read stories.

BACKGROUND:The putative health benefits of forgiveness may include long-term buffering against cardiovascular reactivity associated with rumination. Although studies show short-term benefits of adopting a forgiving perspective, it is uncertain whether this perspective protects against repeated future rumination on offenses, which may be necessary for long-term health benefits. Also unclear is whether forgiveness offers unique benefits beyond simple distraction.METHODS:Cardiovascular parameters (systolic blood pressure [SBP], diastolic blood pressure [DBP], and heart rate) were measured while 202 participants thought about a previous offense from an angry or forgiving perspective or were distracted. All participants were then distracted for 5 minutes, after which they freely ruminated on the offense.RESULTS:Angry rumination initially yielded the greatest increase in blood pressure from baseline (mean [M] [standard deviation {SD}]: SBP = 9.24 [11.16]; M [SD]: DBP = 4.69 [7.48]) compared with forgiveness (M [SD]: SBP = 3.30 [6.48]; M [SD]: DBP = 1.51 [4.94]) and distraction (M [SD]: SBP = 4.81 [6.28]; M [SD]: DBP = 1.75 [3.80]), which did not differ from each other (p > .30). During free rumination, however, those who had previously focused on forgiveness showed less reactivity (M [SD]: SBP = 7.33 [9.61]; M [SD]: DBP = 4.73 [7.33]) than those who had been distracted (M [SD]: SBP = 10.50 [7.77]; M [SD]: DBP = 7.71 [6.83]) and those who previously focused on angry rumination (M [SD]: SBP = 12.04 [11.74]; M [SD]: DBP = 8.64 [12.63]). There were no differences for heart rate.CONCLUSIONS:Forgiveness seems to lower reactivity both during the initial cognitive process and, more importantly, during mental recreations of an offense soon thereafter, potentially offering sustained protection, whereas effects of distraction appear transient.

People are often wrong in estimating both how long tasks have taken in the past and how long they will take in the future. Bias could be due to factors such as task involvement, an individual's engagement or motivation in completing the task, or aspects of the task such as its relative duration or memory storage size associated with it. We examined time estimation bias in actors (likely to experience high levels of task involvement) and observers (likely to experience low levels of task involvement) for both predictions of and memory of task duration. Results suggest that bias appears to be due to memory storage size rather than to involvement with the task.