Joe Hilgard

Illinois State University | ISU · Department of Psychology

We re-analyzed data gathered by Anderson et al. (2010) on the relationship between violent video games and aggressive outcomes. Contrary to the original report, we found evidence of significant publication bias among experiments with aggressive affect or aggressive behavior as an outcome. Results suggest that short-term laboratory effects may be sm...

Recent mass shootings have prompted the idea among some members of the public that exposure to violent video games can have a pronounced effect on individuals with autism spectrum disorder (ASD). Empirical evidence for or against this claim has been missing, however. To address this issue, we assigned adults with and without ASD to play a violent o...

A new measure of individual habits and preferences in video game use is developed in order to better study the risk factors of pathological game use (i.e., excessively frequent or prolonged use, sometimes called "game addiction"). This measure was distributed to internet message boards for game enthusiasts and to college undergraduates. An explorat...

Research on the effects of violent video games frequently relies on arguments for the null hypothesis. Proponents of the effects argue that there are no meaningful differences save violent content between the violent and nonviolent games played, while critics of the effects argue that their nonsignificant study results constitute evidence for the n...

Interpreting a failure to replicate is complicated by the fact that the failure could be due to the original finding being a false positive, unrecognized moderating influences between the original and replication procedures, or faulty implementation of the procedures in the replication. One strategy to maximize replication quality is involving the...

In this reply to Bushman et al. (2022), I explain why differences in method and sample demographics are not likely to explain why the obvious effect in Hilgard (2021) is smaller than the indirect effect in Hasan et al. (2013). Additionally, Bushman and colleagues claim that the large effects can be explained by accumulation of effects across days....

In this reply to Bushman et al. (2022), I explain why differences in method and sample demographics are not likely to explain why the obvious effect in Hilgard (2021) is smaller than the indirect effect in Hasan et al (2013). Additionally, Bushman and colleagues claim that the large effects can be explained by accumulation of effects across days. C...

Replication—an important, uncommon, and misunderstood practice—is gaining appreciation in psychology. Achieving replicability is important for making research progress. If findings are not replicable, then prediction and theory development are stifled. If findings are replicable, then interrogation of their meaning and validity can advance knowledg...

Objective To estimate the overall effect between positive and negative communication behaviors and later relationship quality and dissolution. Background Behavioral models of relationship development argue that the quality of couples' communication is key to understanding later relational outcomes. However, longitudinal studies have yielded incons...

Objective: We quantitatively reviewed the construct validity evidence for all cognitively based indirect measures of sexual interest in prepubescent children (pedophilic interest) and pubescent children (hebephilic interest) using meta-analysis. Method: Studies were included if they presented scores on a cognitively based indirect measure of ped...

Replication, an important, uncommon, and misunderstood practice, is making a comeback in psychology. Achieving replicability is a necessary but not sufficient condition for making research progress. If findings are not replicable, then prediction and theory development are stifled. If findings are replicable, then interrogation of their meaning and...

Effect sizes in social psychology are generally not large and are limited by error variance in manipulation and measurement (Richard, Bond, and Stokes-Zoota, 2003). Effect sizes exceeding these limits are implausible and should be viewed with skepticism. Maximal positive controls, experimental conditions that should show an obvious and predictable...

Most meta-analyses focus on the behavior of meta-analytic means. In many cases, however, this mean is difficult to defend as a construct because the underlying distribution of studies reflects many factors, including how we as researchers choose to design studies. We present an alternative goal for meta-analysis. The analyst may ask about relations...

Does playing action video games improve performance on tests of cognitive ability? A recent meta-analysis (Bediou et al., 2018a) summarized the available evidence and concluded that it can. Their analysis, however, did not adequately correct for publication bias. We re-analyzed the same set of studies with more appropriate adjustments for publicati...

Public trust in agricultural biotechnology organizations that produce so-called ‘genetically-modified organisms’ (GMOs) is affected by misinformed attacks on GM technology and worry that producers' concern for profits overrides concern for the public good. In an experiment, we found that reporting that the industry engages in open and transparent r...

Publication bias and questionable research practices in primary research can lead to badly overestimated effects in meta-analysis. Methodologists have proposed a variety of statistical approaches to correct for such overestimation. However, it is not clear which methods work best for data typically seen in psychology. Here, we present a comprehensi...

Researchers have suggested that acute exposure to violent video games is a cause of aggressive behavior. We tested this hypothesis by using violent and nonviolent games that were closely matched, collecting a large sample, and using a single outcome. We randomly assigned 275 male undergraduates to play a first-person-shooter game modified to be eit...

The ability to independently verify and replicate observations made by other researchers is a hallmark of science. In this article, we provide an overview of recent discussions concerning replicability and best practices in mainstream psychology with an emphasis on the practical benefists to both researchers and the field as a whole. We first revie...

Research into violent videogames has yet to investigate how violence used in videogames for prosocial purposes could affect prosocial behavior. We assigned participants to one of three videogame conditions: an antisocial violence game, a prosocial violence game, or a control game. After gameplay, participants were dismissed from the experiment, but...

Public trust in agricultural biotechnology organizations that produce so-called ‘genetically-modified organisms’ (GMOs) is affected by misinformed attacks on GM technology and worry that producers' concern for profits overrides concern for the public good. In an experiment, we found that reporting that the industry engages in open and transparent r...

Most meta-analyses focus on meta-analytic means, testing whether they are significantly different from zero and how they depend on covariates. This mean is difficult to defend as a construct because the underlying distribution of studies reflects many factors such as how we choose to run experiments. We argue that the fundamental questions of meta-...

How can public support for science be encouraged? In early August 2016, a Zika vaccine entered its first human trial. Extensive media coverage followed. Using repeated cross-sectional surveys, we observed that, following this media coverage, survey respondents reported greater attention to Zika news and an increased trust in science as providing so...

Violent video games are theorized to be a significant cause of aggressive thoughts, feelings, and behaviors. Important evidence for this claim comes from a large meta-analysis by Anderson and colleagues (2010), who found effects of violent games in experimental, cross-sectional, and longitudinal research. In that meta-analysis, the authors argued t...

This study tested whether adults with autism spectrum disorder (ASD) are at higher risk for pathological game use than typically developing (TD) adults. Participants included 119 adults with and without ASD. Participants completed measures assessing daily hours of video game use, percent of free time spent playing video games, and symptoms of patho...

Publication bias and questionable research practices in primary research can lead to badly overestimated effects in meta-analysis. Methodologists have proposed a variety of statistical approaches to correcting for such overestimation. However, much of this work has not been tailored specifically to psychology, so it is not clear which methods work...

This synthesis chapter recapitulates the major themes of Part I. The chapter proposes that science communication is challenging because science is complex, because humans interpret evidence in biased ways, and because the science- media landscape is shifting. Consequently, the mere supply of scientific information alone is not likely to guide audie...

After showing that the frame “science is broken” is beginning to appear in mainstream media, this chapter examines the ways in which retractions and problems in peer review are characterized, both in media and by partisans, as confirmation that the scientific enterprise is untrustworthy. Media coverage of two widely reported retractions is examined...

This synthesis chapter recapitulates the major themes of Part II. These themes concern the various problems within science that may produce misleading results and prevent the correction of errors. These problems include publication bias, bias in statistical analysis, hyping of study results, and, in rare cases, fraud. The collected authors suggest...

In an encyclical released in June of 2015, Pope Francis cast the need to address climate change as a moral imperative. Using nationally-representative surveys with supplemental samples of Catholics, we investigate changes in the U.S. public’s post-encyclical attitudes about climate change and the Catholic pontiff. People who were aware of the encyc...

Although much attention has been paid to the question of whether violent video games increase aggressive behaviour, little attention has been paid to how such games might encourage antecedents of gun violence. In this study, we examined how product placement, the attractive in-game presentation of certain real-world firearm brands, might encourage...

The American Academy of Pediatrics says the evidence is clear, that violent media – including video games – lead to aggression in children. But Joseph Hilgard and colleagues find that much of the experimental evidence, both for and against, is undermined by a tricky statistical weakness. Open access at Significance magazine: http://onlinelibrary.w...

Objectives: The purpose of this study was to better understand the use of screen-based media at bedtime among children with autism spectrum disorder (ASD). The study specifically examined whether the presence of media devices in the child's bedroom, the use of media as part of the bedtime routine, and exposure to media with violent content just be...

Background Meta-analyses play an important role in cumulative science by combining information across multiple studies and attempting to provide effect size estimates corrected for publication bias. Research on the reproducibility of meta-analyses reveals that errors are common, and the percentage of effect size calculations that cannot be reproduc...

Paper accepted for presentation at the 38th annual meeting of the Cognitive Science Society

A recent meta-analysis by Passos and colleagues1 investigated the relationship between inflammatory markers and post-traumatic stress disorder (PTSD). This paper is a valuable resource, and likely to remain so, because effect estimates were obtained in several cases by contact with original authors, when they could not be estimated directly from pu...

Background. Variability in sensitivity to the acute effects of alcohol is an important risk factor for the development of alcohol use disorder (AUD). The most commonly used retrospective self-report measure of sensitivity, the Self-Rating of the Effects of Alcohol form (SRE), queries a limited number of alcohol effects and relies on respondents’ ab...

Background: Variability in sensitivity to the acute effects of alcohol is an important risk factor for the development of alcohol use disorder (AUD). The most commonly used retrospective self-report measure of sensitivity, the Self-Rating of the Effects of Alcohol form (SRE), queries a limited number of alcohol effects and relies on respondents’ ab...

Recent research has suggested that acute exposure to violent video games inhibits the capacity for self-control across neurological, cognitive, and behavioral domains. However, the games used in previous research to reach these conclusions often confound violence with other game features, such as game difficulty. Here, participants were randomly as...

It is widely believed that negative information is psychologically more meaningful than positive information, a phenomenon known generally as the negativity bias. However, findings concerning the possibility of a negativity bias in emotional picture processing have been mixed, with recent studies indicating the lack of such a bias in event-related...

Recent research has identified an important role for task switching, a cognitive control process often associated with executive functioning, in the Implicit Association Test (IAT). However, switching does not fully account for IAT effects, particularly when performance is scored using more recent d-score formulations. The current study sought to c...

It is widely believed that negative information is psychologically more meaningful than positive information, a phenomenon known generally as the negativity bias. However, findings concerning the possibility of a negativity bias in emotional picture processing have been mixed, with recent studies indicating the lack of such a bias in event-relat...

Event-related potential (ERP) studies of early evaluative categorization have often used variants of an oddball paradigm to assess attention to target stimuli as a function of content (i.e., valence) and context (e.g., presentation among non-targets differing in valence). However, most previous studies have not fully crossed content and context, an...

Previous histological and neuroimaging studies have documented structural abnormalities in the white matter of the brain in individuals with early-treated phenylketonuria (ETPKU). It remains unclear, however, the extent to which the function of the brain's interconnections are impacted by this condition. Presently, we utilized functional magnetic r...

Individual discounting rates for different types of delayed reward are typically assumed to reflect a single, underlying trait of impulsivity. Recently, we showed that discounting rates are orders of magnitude steeper for directly consumable liquid rewards than for monetary rewards (Jimura et al., 2009), raising the question of whether discounting...

In previous studies, researchers have found that humans discount delayed rewards orders of magnitude less steeply than do other animals. Humans also discount smaller delayed reward amounts more steeply than larger amounts, whereas animals apparently do not. These differences between humans and animals might reflect differences in the types of rewar...