Peter H Ditto

Peter H Ditto
University of California, Irvine | UCI ·  Department of Psychology and Social Behavior

About

126
Publications
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Introduction
Skills and Expertise

Publications

Publications (126)
Article
Recent studies suggest climate change consensus messages may cause psychological reactance for conservatives. However, it remains unknown how much this reactance impacts the effectiveness of consensus messaging. Using data from a recent meta-analysis on climate change interventions, the current paper seeks to add context to the debate over reactanc...
Article
Full-text available
People believe that effort is valuable, but what kind of value does it confer? We find that displays of effort signal moral character. Eight studies (N = 5,502) demonstrate the nature of these effects in the domains of paid employment, personal fitness, and charitable fundraising. The exertion of effort is deemed morally admirable (Studies 1-6) and...
Preprint
Recent studies suggest climate change consensus messages may cause psychological reactance for conservatives. However, it remains unknown how much this reactance impacts the effectiveness of consensus messaging. Using data from a recent meta-analysis on climate change interventions, the current paper seeks to add context to the debate over reactanc...
Article
Full-text available
In their book, The Coddling of the American Mind, Lukianoff and Haidt (2018) contended that the rise of “safetyism” within American society has inspired beliefs and practices that hinder college students' socioemotional development. One of their most controversial claims was that college students' safetyism-inspired beliefs (e.g., emotional pain or...
Article
Full-text available
Politically oriented “fake news”—false stories or headlines created to support or attack a political position or person—is increasingly being shared and believed on social media. Many online platforms have taken steps to address this by adding a warning label to articles identified as false, but past research has shown mixed evidence for the effect...
Article
The current study investigates how people respond to a climate science consensus statement embedded within a news article. Participants ( N = 1,048) were randomly assigned to read a news article about climate change, read the same article with a scientific consensus message included, read a simple consensus statement, or a control condition. Partic...
Article
Researchers interested in climate change communication have investigated how people respond to messages about it. Through meta-analysis, the current research synthesizes the multitude of experimental studies on this topic to uncover which interventions are most effective at influencing attitudes about climate change. The meta-analysis focuses on ex...
Preprint
In their book, The Coddling of the American Mind, Lukianoff and Haidt (2018) contend that the rise of “safetyism” – cultures that treat safety as a sacred value – is hindering college students’ socioemotional development. One of their most controversial claims was that college students’ safetyism beliefs are rooted in and supported by cognitively d...
Article
Full-text available
In fourteen studies, we tested whether political conservatives’ stronger free will beliefs were linked to stronger and broader tendencies to moralize, and thus a greater motivation to assign blame. In Study 1 (meta-analysis of five studies, n=308,499) we show that conservatives have stronger tendencies to moralize than liberals, even for moralizati...
Article
The present research examines the combined role of the message and source of a news article in persuading political partisans about an environmental policy. In a series of three experiments, we presented participants (total N = 3457) with a realistic news article summarizing scientific evidence concerning the environmental and economic costs and be...
Article
Full-text available
In 14 studies, we tested whether political conservatives' stronger free will beliefs were linked to stronger and broader tendencies to moralize and, thus, a greater motivation to assign blame. In Study 1 (meta-analysis of 5 studies, n = 308,499) we show that conservatives have stronger tendencies to moralize than liberals, even for moralization mea...
Preprint
People believe that effort is valuable, but what kind of value does it confer? We find that displays of effort signal moral character. Importantly, we focus on displays of unproductive or unnecessary effort to highlight the heuristic nature of these intuitions—even “useless” effort is deemed virtuous. We conducted five studies to demonstrate the na...
Article
Full-text available
Humans evolved in the context of intense intergroup competition, and groups comprised of loyal members more often succeeded than those that were not. Therefore, selective pressures have consistently sculpted human minds to be "tribal," and group loyalty and concomitant cognitive biases likely exist in all groups. Modern politics is one of the most...
Article
Rationale: Weight stigma is prevalent in Western society and has numerous negative effects on people with obesity. There remains a strong and currently unmet need to understand why anti-fat attitudes are tenacious and what intervention strategies might best produce lasting attitude change. Objective: Many negative effects of weight stigma can be...
Preprint
Full-text available
Humans evolved in the context of intense intergroup competition, and groups comprised of loyal members more often succeeded than those that were not. Therefore, selective pressures have consistently sculpted human minds to be "tribal," and group loyalty and concomitant cognitive biases likely exist in all groups. Modern politics is one of the most...
Article
Beliefs shape how people interpret information and may impair how people engage in logical reasoning. In three studies, we show how ideological beliefs impair people’s ability to (1) recognize logical validity in arguments that oppose their political beliefs and (2) recognize the lack of logical validity in arguments that support their political be...
Article
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Baron and Jost (this issue) present three critiques of our meta-analysis demonstrating similar levels of partisan bias in liberals and conservatives: 1) that the studies we examined were biased toward finding symmetrical bias among liberals and conservatives, 2) that the studies we examined do not measure partisan bias but rather rational Bayesian...
Preprint
Beliefs shape how people interpret information and may impair how people engage in logical reasoning. In 3 studies, we show how ideological beliefs impair people's ability to: (1) recognize logical validity in arguments that oppose their political beliefs, and, (2) recognize the lack of logical validity in arguments that support their political bel...
Preprint
Full-text available
Both liberals and conservatives accuse their political opponents of partisan bias, but is there empirical evidence that one side of the political aisle is indeed more biased than the other? To address this question, we meta-analyzed the results of 51 experimental studies, involving over 18,000 participants, that examined one form of partisan bias—...
Article
Full-text available
Both liberals and conservatives accuse their political opponents of partisan bias, but is there empirical evidence that one side of the political aisle is indeed more biased than the other? To address this question, we meta-analyzed the results of 51 experimental studies, involving over 18,000 participants, that examined one form of partisan bias—t...
Article
Full-text available
Research has shown that people ascribe more responsibility to morally bad actions than both morally good and neutral ones, suggesting that people do not attribute responsibility to morally good actions. The present work demonstrates that this is not so: People ascribe more free will to morally good than neutral actions (Studies 1a-1b, Mini Meta). S...
Article
Full-text available
Both liberals and conservatives accuse their political opponents of partisan bias, but is there empirical evidence that one side of the political aisle is indeed more biased than the other? To address this question, we meta-analyzed the results of 51 experimental studies, involving over 18,000 participants, that examined one form of partisan bias -...
Preprint
In fourteen studies, we tested whether political conservatives’ stronger free will beliefs aredriven by stronger and broader tendencies to moralize, and thus a greater motivation to assign responsibility. In Study 1 (meta-analysis of five studies, n = 308,499) we show that conservatives have stronger tendencies to moralize than liberals, even for m...
Article
Punishing wrongdoers is beneficial for group functioning, but can harm individual well-being. Building on research demonstrating that punitive motives underlie free will beliefs, we propose that free will beliefs help justify punitive impulses, thus alleviating the associated distress. In Study 1, trait-level punitiveness predicted heightened level...
Article
Full-text available
We present the data from a crowdsourced project seeking to replicate findings in independent laboratories before (rather than after) they are published. In this Pre-Publication Independent Replication (PPIR) initiative, 25 research groups attempted to replicate 10 moral judgment effects from a single laboratory’s research pipeline of unpublished fi...
Article
Full-text available
This crowdsourced project introduces a collaborative approach to improving the reproducibility of scientific research, in which findings are replicated in qualified independent laboratories before (rather than after) they are published. Our goal is to establish a non-adversarial replication process with highly informative final results. To illustra...
Article
We review recent research in moral psychology that demonstrates a fundamental human motivation for a morally coherent world, that is, a world in which the moral qualities of actors and actions match the moral qualities of the outcomes they produce. The striving for moral coherence explains many seemingly contradictory patterns of judgment found in...
Article
Duarte et al. are right to worry about political bias in social psychology but they underestimate the ease of correcting it. Both liberals and conservatives show partisan bias that often worsens with cognitive sophistication. More non-liberals in social psychology is unlikely to speed our convergence upon the truth, although it may broaden the ques...
Article
Full-text available
Research suggesting that political conservatives are happier than political liberals has relied exclusively on self-report measures of subjective well-being. We show that this finding is fully mediated by conservatives' self-enhancing style of self-report (study 1; N = 1433) and then describe three studies drawing from "big data" sources to assess...
Article
Political conservatism has been linked to motivated forms of social cognition, sensitivity to threat, and defensive cognitive styles. The present research examined whether liberal-conservative political ideology was associated with self-enhancement using large Internet samples across eight studies (N=13,002). Meta-analysis of these results revealed...
Article
Previous research in political psychology has found an ideological happiness gap between political conservatives and liberals, in which conservatives report higher happiness levels than liberals; however, recent research has found that this ideological happiness gap essentially reverses when using unobtrusive behavioral measures of subjective well-...
Article
Full-text available
Three studies support the contention that self-enhancement motivation distorts self-reports of subjective well-being (SWB). Both individual differences in self-enhancement (Studies 1 and 2) and experimental manipulations of self-enhancement motivation (Study 2) predicted an increased likelihood of reporting SWB at unrealistically favorable levels r...
Conference Paper
Full-text available
Conference presentation of this paper: https://www.researchgate.net/publication/316164633_At_Least_Bias_Is_Bipartisan_A_Meta-Analytic_Comparison_of_Partisan_Bias_in_Liberals_and_Conservatives#share
Article
Full-text available
Belief in free will is a pervasive phenomenon that has important consequences for prosocial actions and punitive judgments, but little research has investigated why free will beliefs are so widespread. Across 5 studies using experimental, survey, and archival data and multiple measures of free will belief, we tested the hypothesis that a key factor...
Article
Full-text available
Three studies examined the associations between relational adult attachment and moral judgment. Study 1 shows that attachment- related anxiety and avoidance are uniquely and differentially related to moral concerns. Relative to low insecurity, higher avoidance was associated with weaker moral concerns about harm and unfairness, whereas higher anxie...
Article
Full-text available
Rid and Wendler propose the development of a Patient Preference Predictor (PPP), an actuarial model for predicting incapacitated patient’s life-sustaining treatment preferences across a wide range of end-of-life scenarios. An actuarial approach to end-of-life decision making has enormous potential, but transferring the logic of actuarial prediction...
Chapter
Where does morality come from? Why are moral judgments often so similar across cultures, yet sometimes so variable? Is morality one thing, or many? Moral Foundations Theory (MFT) was created to answer these questions. In this chapter, we describe the origins, assumptions, and current conceptualization of the theory and detail the empirical findings...
Article
Full-text available
Companies often provide incentives for employees to maintain healthy lifestyles. These incentives can take the form of either discounted premiums for healthy-weight employees ("carrot" policies) or increased premiums for overweight employees ("stick" policies). In the three studies reported here, we demonstrated that even when stick and carrot poli...
Article
Where does morality come from? Why are moral judgments often so similar across cultures, yet sometimes so variable? Is morality one thing, or many? Moral Foundations Theory (MFT) was created to answer these questions. In this chapter we describe the origins, assumptions, and current conceptualization of the theory, and detail the empirical findings...
Article
Full-text available
Libertarians are an increasingly prominent ideological group in U.S. politics, yet they have been largely unstudied. Across 16 measures in a large web-based sample that included 11,994 self-identified libertarians, we sought to understand the moral and psychological characteristics of self-described libertarians. Based on an intuitionist view of mo...
Article
a b s t r a c t Commentators have noted that the issue stands taken by each side of the American ''culture war'' lack conceptual consistency and can even seem contradictory. We sought to understand the psychological underpinnings of culture war attitudes using Moral Foundations Theory. In two studies involving 24,739 participants and 20 such issues...
Article
Full-text available
The current studies examined if cultural and self-construal differences in self-enhancement extended to defensive responses to health threats. Responses to fictitious medical diagnoses were compared between Asian-Americans and European-North Americans in experiment 1 and between Canadians primed with an interdependent versus an independent self-con...
Article
Moral dilemmas — like the “trolley problem” or real world examples like capital punishment — result from a conflict between consequentialist and deontological intuitions (i.e., whether ends justify means). We contend that people often resolve such moral conflict by aligning factual beliefs about consequences of acts with evaluations of the act’s in...
Article
Full-text available
The moral domain is broader than the empathy and justice concerns assessed by existing measures of moral competence, and it is not just a subset of the values assessed by value inventories. To fill the need for reliable and theoretically grounded measurement of the full range of moral concerns, we developed the Moral Foundations Questionnaire on th...
Article
Full-text available
Moral dilemmas — like the “trolley problem” or real world examples like capital punishment — result from a conflict between consequentialist and deontological intuitions (i.e., whether ends justify means). We contend that people often resolve such moral conflict by aligning factual beliefs about consequences of acts with evaluations of the act’s in...
Article
Full-text available
Our inability to feel what others feel makes it difficult to understand how they think. Because moral intuitions organize political attitudes, moral empathy gaps can exacerbate political conflict (and other kinds of conflict as well) by contributing to the perception that people who do not share our moral opinions are unintelligent and/or have male...
Article
This study examined the hypothesis that negative social information attracts more processing resources than positive social information. Ninety-three women were asked to choose which of two male students was the better writer. Half the subjects were told that they would return in the future to write an essay on abortion with the student chosen as t...
Chapter
To say that someone is a person of principle is high praise; to declare that he or she is driven by personal preference is a damning critique. This chapter examines judgments of preference and principle from a social-psychological perspective, arguing that they reflect lay-psychological hypotheses concerning the causes of behavior. It is argued tha...
Article
Full-text available
Several scholars have recognized the limitations of theories of moral reasoning in explaining moral behavior. They have argued that moral behavior may also be influenced by moral identity, or how central morality is to one's sense of self. This idea has been supported by findings that people who exemplify moral behavior tend to place more impo...
Article
Libertarians are an increasingly vocal ideological group in U.S. politics, yet they are understudied compared to liberals and conservatives. Much of what is known about libertarians is based on the writing of libertarian intellectuals and political leaders, rather than surveying libertarians in the general population. Across three studies, 15 measu...
Article
The two leading candidates for the 2008 Democratic Party presidential nomination, Barack Obama and Hillary Clinton, had very similar policy positions and yet demonstrated appeal to disparate populations. Much has been written in the press about demographic differences between supporters of these candidates, but little is known about these groups’ p...
Article
The tendency to believe that the future will be consistent with desires is perhaps the best documented bias that influences human thought. Despite decades of research on this desirability bias, very few studies have addressed what is meant by desire or how desires influence judgments about the future. The goal of this chapter is to provide a novel...
Article
Moral judgments are important, intuitive, and complex. These factors make moral judgment particularly fertile ground for motivated reasoning. This chapter reviews research (both our own and that of others) examining two general pathways by which motivational forces can alter the moral implications of an act: by affecting perceptions of an actor's m...
Article
Full-text available
Five studies demonstrated that people selectively use general moral principles to rationalize preferred moral conclusions. In Studies 1a and 1b, college students and community respondents were presented with variations on a traditional moral scenario that asked whether it was permissible to sacrifice one innocent man in order to save a greater numb...