Null Results Research Articles

Contradict them softly! Contradictions of the subject feel less true than contradictions of the object

ABSTRACT Individuals attribute a higher truth value to repeated compared to novel information, the well-known truth effect. Also, information that contradicts what we have heard earlier is considered falser than both repeated and completely new information, known as the contradiction effect. These two effects are a challenge to the correction of misinformation because one cannot easily correct earlier misleading claims. In the present paper, we show a new and important factor that enhances the effectiveness of corrections, the syntactic placement of the contradiction. We argue that because the subject of a sentence has a stronger psychological importance than the object, a contradiction of the subject (compared to the object) is felt as a stronger contrast to the earlier information and thus experienced as more false. Experiments 1 and 2 provided null results, possibly due to confounding material and task. Crucially, Experiments 3–5 (total N = 628) reliably showed that contradictions of the subject were perceived to be falser than contradictions of the object.

Debate: Where to next for universal school-based mental health interventions? Tensions in prevention - To build better school-based programming, we must start with what we know.

Researchers and education leaders have suggested that universal school-based prevention programs could improve youth mental health at a population level, yet recent trials of universal school-based prevention programs (e.g., MYRIAD, CSC) found null or iatrogenic results. In this debate piece, we argue that these results must be contextualized alongside existing knowledge that universal programs are ideally implemented within multitiered systems, promoting student autonomy tends to promote uptake and adherence, and individual trials do not outweigh decades of academic and community expertise. We offer suggestions for moving forward in research on and implementation of universal school-based prevention programs.

Age-related changes in attentional selection: revealing processes underlying the degradation of task set quality.

The present study further explored the age-related changes in attentional selection, first reported by Jackson and Balota Jackson and Balota (Psychology and Aging 28:3, 2013). To this end, response stimulus interval (RSI) was manipulated in in a Stroop paradigm that allows to isolate different components of the overall Stroop effect. The originally reported reduction of the overall Stroop effect in short (vs. long) RSI was successfully replicated. In line with the original claim that the ability to maintain the relevant task set consistently across time is preserved in older adults, this reduction failed to interact again with age - a null result that was uniquely supported in the present study with Bayesian evidence. Although healthy aging affected all components of the overall Stroop effect, the present study further identified interference and a disproportionally larger semantic conflict effect, as being the primary mechanisms behind the larger overall Stroop effect that older adults produce compared to younger adults. These results therefore directly fuel the original conclusion of Jackson and Balota Jackson and Balota (Psychology and Aging 28:3, 2013) that age-related differences in attentional selection are due the degradation of task set quality, namely a lesser ability of older adults to control interference. The present study additionally showed this reduced control of interference directly and identified where in the processing stream it occurs. The immediate implication that challenges the dominant unitary models of Stroop performance, is that future interventions designed to boost interference control in older adults should most likely target semantic, as opposed to response conflict.

Voter Preferences for Ethnoracial Minority Candidates: The Role of Policy Alignment and Shared Identity

Abstract Existing research suggests that ethnoracial majority voters favor coethnic candidates over those from ethnoracial minorities due to stereotypical inferences about policy positions based on ethnic group and shared group identity. This study examines whether coethnic bias can be mitigated when ethnic minority candidates adopt policy positions favorable to ethnoracial majorities and share a common group identity with them. We conducted a pre-registered survey experiment with Japanese voters, using vignettes that varied a hypothetical candidate’s origin, name, and migrant policy proposals. Our findings indicate that ethnoracial majority respondents do not necessarily disfavor ethnic minority candidates. Furthermore, policy positions and shared identity do not mitigate candidate preferences. However, this null result is driven by heterogeneous responses to the candidates’ ethnic origins based on perceived threats. Voters who perceive higher threats from ethnoracial minorities are more likely to negatively evaluate ethnic minority candidates, whereas those perceiving lower threats tend to evaluate them positively.

Does Saying “Thanks a Lot” Make You Look Less Than? The Magnitude of Gratitude Shapes Perceptions of Relational Hierarchy

Gratitude expressions provide shared warmth benefits to both the thanker and the helper. Little work has explored how gratitude expressions shift how observers see these individuals on another important dimension: their relative rank. We consider how the magnitude of gratitude expressions shapes observers’ perceptions of the thanker’s and helper’s relative status and power. Seven studies find that thankers who expressed more, compared to less, intense gratitude than expected made their helpers seem relatively higher rank, though this pattern was inconsistent across metrics of gratitude in studies using real-world expressions. These effects emerged across a range of contexts and relationships. Mechanism analyses yielded several null results, while underscoring the role of perceptions of agency. Observers may make their inferences directly, based on intuiting the real association between a thanker’s gratitude and their helper’s power and status. Our findings demonstrate that gratitude signals rank relationships, qualifying current recommendations to express gratitude publicly.

Theoretical bounds on dark Higgs mass in a self-interacting dark matter model with U(1)′

Motivated by the null results of current dark matter searches and the small-scale problems, we study a dark sector charged by a spontaneous broken gauge U(1)′. To explore the parameter space of this model, in addition to the consideration of the small-scale data, we also consider the theoretical bounds on the dark Higgs mass, with the upper bound coming from the tree-level perturbative unitarity and the lower bound from the one-loop Linde-Weinberg bound. We deeply examine the dependence of the Linde-Weinberg bound on gauge choice and energy scale, and present a Linde-Weinberg bound that is gauge and scale independent. Combining the theoretical and observational constraints, we obtain the following ranges for the parameter space: the dark matter mass is 10–500 GeV, the mediator (dark photon) mass is 0.5–5 MeV, the dark Higgs mass is 0.05–50 MeV, and the dark fine-structure constant is 0.001–0.4. We conclude that the dark Higgs in this model cannot be ignored in the phenomenological study of the dark sector. Published by the American Physical Society 2025

Designing and Implementing Experiments within Local Bureaucratic Systems: A Cautionary Tale from an Educator Incentive Program

Abstract Partnering with governments to co-design pilot interventions and embed them in local bureaucratic systems is increasingly seen as “best practice” on grounds of scalability and sustainability. This paper reports on a pilot program that was co-designed with, and embedded within, the Elementary and Secondary Education Department in Pakistan's Khyber Pakhtunkhwa province that offers a cautionary tale. The over-arching desire to work within existing bureaucratic systems, while laudable, constrained the design of the randomized controlled trial. This paper presents findings on some of the institutional factors which resulted in failed implementation of the randomized controlled trial and a lost opportunity to learn about the efficacy of key design features. The paper briefly outlines the design of the pilot—promotion-based incentives for educators—and summarizes the largely null results. It then turns to implementation, discussing what went wrong, how this was uncovered, and lessons learned for co-designing and embedding future pilot studies with(in) government.

The association between maternal immune activation and brain structure and function in human offspring: a systematic review.

Maternal immune activation (MIA) during pregnancy, as a result of infectious or inflammatory stimuli, has gained increasing attention for its potential role in adverse child neurodevelopment, with studies focusing on associations in children born preterm. This systematic review summarizes research on the link between several types of prenatal MIA and subsequent child structural and/or functional brain development outcomes. We identified 111 neuroimaging studies in five MIA areas: inflammatory biomarkers (n = 13), chorioamnionitis (n = 18), other types of infections (n = 18), human immunodeficiency virus (HIV) (n = 42), and Zika virus (n = 20). Overall, there was large heterogeneity in the type of MIA exposure examined and in study methodology. Most studies had a prospective single cohort design and mainly focused on potential effects on the brain up to one year after birth. The median sample size was 53 participants. Severe infections, i.e., HIV and Zika virus, were associated with various types of cerebral lesions (e.g., microcephaly, atrophy, or periventricular leukomalacia) that were consistently identified across studies. For less severe infections and chronic inflammation, findings were generally inconsistent and mostly included deviations in white matter structure/function. Current findings have been mainly observed in the infants' brain, presenting an opportunity for future studies to investigate whether these associations persist throughout development. Additionally, the inconsistent findings, encompassing both regions of interest and null results, call into question whether prenatal exposure to less severe infections and chronic inflammation exerts a small effect or no effect on child brain development.

Galactic and extragalactic probe of dark matter with LISA's binary black holes

The upcoming LISA mission will be able to detect gravitational waves from galactic and extragalactic compact binaries. Here, we report on LISA's capability to probe dark matter around these binaries if the latter constitute black holes. By analyzing the variation in the chirp mass of the binary, we show that depending on the black hole masses, LISA should be able to probe their surrounding dark matter to a luminosity distance of ≈ 1 Gpc if such binaries are located within the inner ≈ 10 pc of their galactic center for particle-like dark matter or near the galactic solitonic core for wave-like dark matter. However, for the latter, the density of dark matter near the galactic center must be higher than predicted from dark matter only simulations. Even if a null result is recorded during the course of observation of well-localized binaries, one can rule out certain parameter spaces of dark matter as being the dominant contributor to the matter budget of the Universe.

Randomized Controlled Trials of Exercise Training and Its Health Benefits: Integrating the NIH Stage Model of Intervention Development With Research Design Approaches for Avoiding a Crisis

Randomized controlled trials (RCTs) are the gold standard of research design and therefore provide the bedrock of evidence for claims regarding the health benefits of exercise training across the human lifespan. Nevertheless, there is substantial heterogeneity between RCTs regarding the outcomes of exercise training, as RCTs sometimes provide null or negative results regarding changes in outcomes, and positive results might even suffer from a lack of reproducibility by other scientists. This paper reviews the National Institutes of Health (NIH) Stage Model of Intervention Development and then identifies aligning research approaches and design considerations for informing and conducting RCTs of exercise training and its health benefits. The primary goal is the provision of a thoughtful and deliberate approach for designing RCTs that yield strong and reproducible research results regarding the health benefits of exercise training. This is necessary for strengthening the science behind the implementation and dissemination of evidence-based exercise training programs.

Registered reports in psychology across scholarly citations and public dissemination: A comparative metaevaluation of more than a decade of practice.

After more than a decade of practice, registered reports (RRs) are widely adopted in psychology. However, the acceptance of RRs in terms of postpublication academic recognition and public dissemination, compared with nonregistered reports (non-RR), remained largely unexplored. This matched meta-evaluation identified and analyzed 119 pairs of original research articles (RR vs. non-RR) from 33 psychology journals, matched for the journal of publication, time of publication, and research topic. The exploratory results show that RRs significantly reduced publication bias against null results and improved method and data transparency. However, RRs had lower citation counts than non-RRs, with a small effect size when controlling for days since publication. Additional exploratory analyses found that this effect remained significant after controlling for null-result reporting, transparency, the number of studies in an article and length of method and result sections, article title perception, open access, and authorship metrics (including the number of authors, the h-index of the first or corresponding authors). The overall public impact indexed by Altmetric attention scores and the number of Twitter posts were not significantly different between RRs and non-RRs. However, Twitter posts, but not citations and Altmetric attention scores, were moderated by journal reputation, with RRs receiving more attention in lower impact journals (5-year impact factor below 4.5). These exploratory findings help generate testable hypotheses about the potential differential effects of RRs on academic recognition and public attention, informing future directions for open science practice. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

The NCORES programme: precise planetary masses, null results, and insight into the planet mass distribution near the radius gap

ABSTRACT NCORES was a large observing programme on the ESO HARPS spectrograph, dedicated to measuring the masses of Neptune-like and smaller transiting planets discovered by the TESS satellite using the radial velocity technique. This paper presents an overview of the programme, its scientific goals and published results, covering 35 planets in 18 planetary systems. We present spectrally derived stellar characterization and mass constraints for five additional TOIs where radial velocity observations found only marginally significant signals (TOI-510.01, $M_p = 1.08^{+0.58}_{-0.55}{\rm M}_{\rm{\oplus }}$), or found no signal (TOIs 271.01, 641.01, 697.01, and 745.01). A newly detected non-transiting radial velocity candidate is presented orbiting TOI-510 on a 10.0 d orbit, with a minimum mass of $4.82^{+1.29}_{-1.26}{\rm M}_{\rm{\oplus }}$, although uncertainties on the system architecture and true orbital period remain. Combining the NCORES sample with archival known planets, we investigate the distribution of planet masses and compositions around and below the radius gap, finding that the population of planets below the gap is consistent with a rocky composition and ranges up to a sharp cut-off at $10M_{\rm{\oplus }}$. We compare the observed distribution to models of pebble- and planetesimal-driven formation and evolution, finding good broad agreement with both models while highlighting interesting areas of potential discrepancy. Increased numbers of precisely measured planet masses in this parameter space are required to distinguish between pebble and planetesimal accretion.

Perceptions of Academic Malpractice are not Always Biased by Halo Effects.

The attractiveness halo effect has been discussed for over a century. Physically attractive people are often judged more favourably and accrue many life advantages. Halo effects have been observed in university settings for decades, but perhaps their influence is waning due to increased awareness of unconscious bias. The first study examined judgments of students accused of academic malpractice. Undergraduate student participants (N = 302) completed an online survey. They were presented with a vignette outlining a fictional but realistic academic malpractice scenario, beside a photograph of an attractive or unattractive 'student'. Participants rated the fictional student in terms of guilt, appropriate punishment, and seriousness of malpractice. There was no evidence for halo effects. The second study examined judgements of fictional researchers accused of questionable research practices. Psychology researchers (N = 42) completed another online survey. They were presented with a vignette describing dubious data manipulation, beside a photo of an attractive or unattractive 'researcher'. The same rating scales were used, and again, there were no halo effects. Evidently, university students and staff can sometimes make professional judgements without emotional bias. These null results are important, because they show that halo effects may not now be so pervasive.

P0837 Prevalence of the HLA-DQA1*05 phenotype in a cohort of Spanish patients with Inflammatory Bowel Disease, and its association with the response to first anti-TNF therapy in real-world settings

Abstract Background Anti-tumor necrosis factor (anti-TNF) drugs usually represent the first line of biological therapy in inflammatory bowel disease (IBD) patients. The presence of the HLA-DQA1*05 allele has been linked to a higher risk of immunogenicity and the development of anti-drug antibodies. This condition may increase the likelihood of primary treatment failure or loss of response to anti-TNF medications. However, clinical data on this topic are scarce and often contradictory. Methods Prospective, single-center cohort study in bio-naive IBD patients receiving the first anti-TNF medication for IBD activity from 1 January 2020 to 31 December 2023. PCR-SSP using the HLA-Ready Gene Coeliac Disease kit detected the DQA1*05 allele in a saliva sample. The result was positive if the DQA1*05:01:01,03 or DQA1*05:01:01,05,08 alleles were present. Patients were followed from first dose to discontinuation or last visit. The primary endpoint was anti-TNF persistence, considering as treatment failures, IBD patients with primary or secondary loss of response, and anti-TNF discontinuation due to adverse events. An appropriate statistical analysis was performed using survival Kaplan-Meier curves to assess anti-TNF persistence. Results We included 209 patients:108 men (51.7%), mean age 43.5 (17) and time since diagnosis 6.5 (10) years. Ulcerative colitis 39.2% and Crohn´s Disease 60.8%. As the first anti-TNF, 107 patients received adalimumab (51.2%) and 101 infliximab. Baseline demographics for the cohort are summarized in Table 1. At anti-TNF initiation, 29.2% and 58% of patients were on immunosuppressants and systemic steroids, respectively. HLA-DQA1*05 was determined in 205 patients with 38.8% (81) positive, 54.5% (114) negative and 4.8% (10) null results. HLA carriers did not differ according to gender, age or IBD clinical phenotype. A total of 87 patients (41.6%) discontinued treatment during a median follow-up of 22.3 (10-36) months, mostly infliximab 59,3% vs 41% (p=0.009). At 12 and 24 weeks, primary anti-TNF failure was reported in 24 (11.5%) and 34 (16.3%) patients, respectively. Anti-TNF was discontinued in another 23 patients (11%) because of loss of response and in 22 (10.5%) for serious adverse events, mainly infusion reactions (5.7%). The mean persistence of first anti-TNF was similar in allele carriers 36.7 CI95%(31.5-41.9) versus naive 33.8 CI 95%(29.6-38.1) months (Figure 1). Conclusion HLA-DQA1*05 ihaplotype is carried by 40%, of bio-naive Spahish IBD patients, a similar prevalence to that obtained in other western IBD populations. HLA-DQA1*05 carrier status was not associated with IBD clinical phenotypes or persistence on the first anti-TNF treatment. References Spencer EA, Stachelski J, Dervieux T et al. Failure to achieve target drug concentrations during induction and not HLA-DQA1∗05 carriage is associated with antidrug antibody formation in patients with Inflammatory Bowel Disease. Gastroenterology. 2022;162(6):1746-48. Pascual-Oliver A, Casas-Deza D, Cuarán C et al. HLA-DQA1*05 was not associated with primary nonresponse or loss of response to first anti-TNF in real-world Inflammatory Bowel Disease patients. Inflamm Bowel Dis.2024; 3:30 (6):922-929.

Non-dominant hand contractions do not facilitate performance under pressure in common desktop tasks.

Non-dominant hand contractions (NDHCs) have been shown to help expert motor skills in high-pressure scenarios that induce performance anxiety. Most studies of NHDCs under pressure have examined benefits in overlearned specialist movements (e.g., sporting skills), while few have considered if NDHCs can aid common movements with population-wide expertise (e.g., typing). Accordingly, across three experiments, we explored if NDHCs could protect or facilitate performance under time and/or evaluation pressure in a cursor positioning task (Experiments 1 & 2) and a typing task (Experiment 3). Despite varying the nature of the task, pressure manipulation, and design, and successfully manipulating state anxiety in each experiment, we found no evidence that NDHCs assist performance under pressure in these tasks. For the pressure × contraction condition interaction, the largest inclusion Bayes Factor was .40 for task response time and .62 for task error (Experiment 1), indicating evidence in favour of a null result. Our results, along with other recent studies in this area, cast doubt on the benefits of NDHCs under pressure outside sporting tasks and underline the need for a better mechanistic account of the phenomenon.

The impact of recreational cannabis retailer allocation on emergency department visits: A natural experiment utilizing lottery design.

The impact of recreational cannabis retailer allocation on emergency department visits: A natural experiment utilizing lottery design.

No significant relationship found between spontaneous motor tempo, heartbeat, and individual alpha frequency: an analysis of internal tempos

Many theories of time perception propose the existence of an internal pacemaker, and studies across behavioral, physiological, and neuroscience fields have explored this concept. Specifically, Spontaneous Motor Tempo (SMT), the most comfortable and natural tapping tempo for each individual, is thought to reflect this internal pacemaker’s tempo. Changes in heart rate are also linked to time estimation, while Individual Alpha Frequency (IAF), the peak in the alpha range (8–13 Hz) observed in EEG, is reported to reflect the brain’s temporal processing. Despite the associations of SMT, heart rate, and IAF with intrinsic tempo, their interrelations remain unexplored. In this pre-registered study, we measured SMT, IAF, and heart rate in 32 healthy university students aged 18–21 and examined how these variables relate to each other. During the experiment, participants sat with their eyes closed for 5 min while we recorded their EEG and heart rate. They then tapped the space key with their index finger at their most comfortable tempo, which we used to determine SMT. Participants also completed a questionnaire about their age, chronotype, and musical experience. Our results showed no significant correlations among SMT, heart rate, and IAF. Regression analysis further confirmed that SMT is not influenced by heart rate or IAF. Therefore, no significant relationships among behavioral, physiological, and neuroscience-related tempo were uncovered. Our contribution lies in measuring SMT, heart rate, and IAF within the same experimental context. All procedures, including scripts used for the analyses, were pre-registered before data collection, and we report these null results to mitigate publication bias.

Guidance and Considerations When Performing Data-Validity Checks.

This response to a Commentary by Delgado-Ron, Jeyabalan, Watt, and Salway (2024) on Cimpian, Timmer, and Kim's (2023) paper discusses and clarifies some key issues in applying the new data-validity sensitivity analysis proposed by Cimpian etal. (2023). The differences in the applications of the method by Delgado-Ron etal. (2024) and Cimpian etal. (2023) present an opportunity to recognize the possibilities of this method, while also noting some challenges and limitations. This response-commentary focuses on five key areas: (1) surmising a set of likely motivations of the survey respondents, (2) selecting the screener items, (3) considering the outcomes examined, (4) reflecting on null results in a sensitivity analysis, and (5) recognizing the advantages and disadvantages of the ease of this new method.

The Effect of Students with Special Needs on Their Peers’ Cognitive Outcomes: Results from Student-Level Population Data in the Netherlands

Abstract This paper presents evidence that students with special needs (SN) have no impact on the academic achievement of their peers in primary and secondary schools in the Netherlands. Administrative data are used on all Dutch students who are in their final grade of primary and secondary education in the years 2015–18 and student and school fixed effect models are estimated to find this null finding. To establish if the results truly represent a null finding a conceptual framework for learning from null results is applied. These results support that the inclusion on students without SN has no impact: Point estimates are precise and coefficients are generally insignificant and inconsistent in sign. Our results nuance recent empirical findings, and provide further evidence that, depending on the educational context, inclusive education can be implemented without harming the academic achievement of students without special needs.

Transcutaneous Auricular Vagus Nerve Stimulation Does Not Accelerate Fear Extinction: A Randomized, Sham-Controlled Study.

Transcutaneous auricular vagus nerve stimulation (taVNS) has been tested as a strategy to facilitate fear extinction learning based on the hypothesis that taVNS increases central noradrenergic activity. Four studies out of six found taVNS to enhance extinction learning especially at the beginning of extinction. Facilitatory effects of taVNS were mainly observed in US expectancy, less in fear-potentiated startle (FPS), and not in the skin conductance response (SCR). Suboptimal stimulation parameters may explain the reported mixed results. Also, variability in selected fear conditioning paradigms and statistical power impedes the comparability between studies. This study sought to further test whether taVNS accelerates fear extinction learning as indexed by US expectancy, FPS, and SCR. Similar to most previous studies, we employed a differential fear conditioning paradigm. The left ear of 79 healthy participants was stimulated with either sham (earlobe) or taVNS (cymba concha) during extinction learning. To maximize the beneficial effects of taVNS, the stimulation of the left cymba concha was administered continuously at the maximum level below the pain threshold. Results of the pre-registered frequentist and exploratory Bayesian analyses indicate that taVNS did not accelerate extinction learning in any of the outcomes. The null results indicate that taVNS with commonly used stimulation parameters does not reliably optimize fear extinction learning. More research is needed to test if the stimulation protocol determines the efficacy of taVNS in optimizing fear extinction learning.