scholarly journals Meta-analysis challenges a textbook example of status signalling: evidence for publication bias

2018 ◽  
Author(s):  
Alfredo Sánchez-Tójar ◽  
Shinichi Nakagawa ◽  
Moisès Sánchez-Fortún ◽  
Dominic A. Martin ◽  
Sukanya Ramani ◽  
...  
Keyword(s):  
Effect Size ◽  
Meta Analysis ◽  
Dominance Rank ◽  
Passer Domesticus ◽  
Medium Effect ◽  
Species Variation ◽  
Status Signalling ◽  
Unpublished Studies ◽  
The Status ◽  
Medium Effect Size

AbstractThe status signalling hypothesis aims to explain conspecific variation in ornamentation by suggesting that some ornaments signal dominance status. Here, we use multilevel meta-analytic models to challenge the textbook example of this hypothesis, the black bib of house sparrows (Passer domesticus). We conducted a systematic review, and obtained raw data from published and unpublished studies to test whether dominance rank is positively associated with bib size across studies. Contrary to previous studies, our meta-analysis did not support this prediction. Furthermore, we found several biases in the literature that further question the support available for the status signalling hypothesis. First, the overall effect size of unpublished studies was zero, compared to the medium effect size detected in published studies. Second, the effect sizes of published studies decreased over time, and recently published effects were, on average, no longer distinguishable from zero. We discuss several explanations including pleiotropic, population- and context-dependent effects. Our findings call for reconsidering this established textbook example in evolutionary and behavioural ecology, raise important concerns about the validity of the current scientific publishing culture, and should stimulate renewed interest in understanding within-species variation in ornamental traits.

scholarly journals Meta-analysis challenges a textbook example of status signalling and demonstrates publication bias

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Alfredo Sánchez-Tójar ◽  
Shinichi Nakagawa ◽  
Moisès Sánchez-Fortún ◽  
Dominic A Martin ◽  
Sukanya Ramani ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Dominance Rank ◽  
Passer Domesticus ◽  
Primary Data ◽  
Species Variation ◽  
House Sparrows ◽  
Status Signalling ◽  
Unpublished Studies ◽  
The Status ◽  
Ornamental Traits

The status signalling hypothesis aims to explain within-species variation in ornamentation by suggesting that some ornaments signal dominance status. Here, we use multilevel meta-analytic models to challenge the textbook example of this hypothesis, the black bib of male house sparrows (Passer domesticus). We conducted a systematic review, and obtained primary data from published and unpublished studies to test whether dominance rank is positively associated with bib size across studies. Contrary to previous studies, the overall effect size (i.e. meta-analytic mean) was small and uncertain. Furthermore, we found several biases in the literature that further question the support available for the status signalling hypothesis. We discuss several explanations including pleiotropic, population- and context-dependent effects. Our findings call for reconsidering this established textbook example in evolutionary and behavioural ecology, and should stimulate renewed interest in understanding within-species variation in ornamental traits.

Effects of Acupressure on Anxiety: A Systematic Review and Meta-Analysis

2015 ◽  
Vol 33 (5) ◽  
pp. 353-359 ◽  
Author(s):  
Doreen W H Au ◽  
Hector W H Tsang ◽  
Paul P M Ling ◽  
Christie H T Leung ◽  
P K Ip ◽  
...  
Keyword(s):  
Effect Size ◽  
Citation Index ◽  
Meta Analysis ◽  
Allocation Concealment ◽  
Risk Of Bias ◽  
Medium Effect ◽  
Physiological Indicators ◽  
Medium Effect Size ◽  
Mean Differences ◽  
Randomised Controlled

Objective To evaluate the evidence from randomised controlled trials (RCTs) and quantify the effects of acupressure on anxiety among adults. Methodology RCTs published between January 1997 and February 2014, comparing acupressure with sham control, were identified from the databases Science Citation Index/Social Sciences Citation Index, Scopus, PubMed and PsycINFO. Meta-analysis of eligible studies was performed and the magnitude of the overall effect size was calculated for the anxiety outcome. Revised STRICTA (the Standards for Reporting Interventions in Clinical Trials of Acupuncture) criteria were used to appraise the acupressure procedures, and the Cochrane risk of bias tool was used to assess the methodological quality of the studies. Results Of 39 potentially relevant studies, seven RCTs met the inclusion criteria for review while five studies met the criteria for meta-analysis. All studies reported the positive effect of acupressure on relieving anxiety from the anticipation of surgery or treatment. EX-HN3 ( Yintang), HT7 ( Shenmen) were the commonest points selected and two studies used bilateral points. The acupressure procedure was generally well reported and studies had a low risk of bias. The combined results of the five trials showed a greater overall reduction in anxiety in the acupressure group than in the sham controls (standardised mean differences (SMD)=−1.11; 95% CI −1.61 to −0.61; p<0.0001 heterogeneity: I2=75%; χ2=16.17; p=0.003; r=0.485). Conclusions Acupressure seems to be effective in providing immediate relief of pretreatment anxiety among adults, and has a medium effect size. However, conflicting results were found for the improvements on physiological indicators. More rigorous reporting, including allocation concealment procedure, is needed to strengthen the results.

When the Eye Listens: A Meta-analysis of How Audio-visual Presentation Enhances the Appreciation of Music Performance

2012 ◽  
Vol 30 (1) ◽  
pp. 71-83 ◽  
Author(s):  
Friedrich Platz ◽  
Reinhard Kopiez
Keyword(s):  
Effect Size ◽  
Music Perception ◽  
Meta Analysis ◽  
Music Performance ◽  
Visual Presentation ◽  
Medium Effect ◽  
Total N ◽  
Visual Component ◽  
Visual Music ◽  
Medium Effect Size

the visual component of music performance as experienced in a live concert is of central importance for the appreciation of music performance. However, up until now the influence of the visual component on the evaluation of music performance has remained unquantified in terms of effect size estimations. Based on a meta-analysis of 15 aggregated studies on audio-visual music perception (total N = 1,298), we calculated the average effect size of the visual component in music performance appreciation by subtracting ratings for the audio-only condition from those for the audio-visual condition. The outcome focus was on evaluation ratings such as liking, expressiveness, or overall quality of musical performances. For the first time, this study reveals an average medium effect size of 0.51 standard deviations — Cohen's d; 95% CI (0.42, 0.59) — for the visual component. Consequences for models of intermodal music perception and experimental planning are addressed.

scholarly journals Effects of Physical Activity Programs on the Improvement of Dementia Symptom: A Meta-Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Han Suk Lee ◽  
Sun Wook Park ◽  
Yoo Jung Park
Keyword(s):  
Physical Activity ◽  
Effect Size ◽  
Meta Analysis ◽  
Physical Capacity ◽  
Medium Effect ◽  
Psychological State ◽  
High Effect Size ◽  
High Effect ◽  
Medium Effect Size ◽  
Meta Analyses

Objective. To confirm that physical activity program improves the symptoms of dementia and the most effective physical activity was selected to help establish exercise programs.Methods. Three databases, PubMed, Science Direct, and Willey online, were used to collect articles. The databases were published between January 2005 and December 2015. Keywords such as “dementia,” and “physical activity” were used in searching for papers. As a result, nine studies were selected in the second screening of the meta-analyses.Results. The improvement in the dementia symptom of physical capacity was 1.05 (high effect size, 95% CI: 0.03 to 0.73), ability of activity of daily living was 0.73 (slightly high effect size, 95% CI: 0.23 to 1.23), cognitive function was 0.46 (medium effect size, 95% CI: 0.26 to 0.66), and psychological state was 0.39 (lower than the medium effect size, 95% CI: 0.01 to 0.77).Conclusion. The physical activity for patients with dementia had an effect on the improvement of physical capacity and combined exercise was the most effective physical activity.

A Meta-Analysis of Facebook-Assisted Learning Outcomes and Their Gender Differences

2021 ◽  
Vol 13 (4) ◽  
pp. 63-82
Author(s):  
*Zhonggen Yu ◽  
Liheng Yu
Keyword(s):  
Gender Differences ◽  
Social Media ◽  
Learning Outcomes ◽  
Effect Size ◽  
Meta Analysis ◽  
Medium Effect ◽  
Future Research ◽  
Small Effect Size ◽  
Medium Effect Size ◽  
Media Applications

Social media applications such as Facebook have received wide attention in their use in education. However, it is still hard to arrive at a conclusion regarding whether a Facebook-assisted approach is effective in education and whether there are any significant gender differences in the learning outcomes. Based on rigid inclusion criteria, this study included 21 peer-reviewed high-quality journal articles. Through a meta-analysis using Reviewer Manager 5.3, the authors concluded that a Facebook-assisted approach could obtain significantly higher learning outcomes than the non-Facebook-assisted one with a medium effect size (d = 0.42) and that females could achieve significantly better learning outcomes than males with a very small effect size (d = -0.21) in the Facebook-assisted education. Future research could examine the effect of educational use of other social media applications, as well as in sociological, psychological, or educational dimensions.

Steep discounting of delayed monetary and food rewards in obesity: a meta-analysis

2016 ◽  
Vol 46 (11) ◽  
pp. 2423-2434 ◽  
Author(s):  
M. Amlung ◽  
T. Petker ◽  
J. Jackson ◽  
I. Balodis ◽  
J. MacKillop
Keyword(s):  
Publication Bias ◽  
Effect Size ◽  
Meta Analysis ◽  
Case Control ◽  
Medium Effect ◽  
Primary Analysis ◽  
Medium Effect Size ◽  
Meta Regression ◽  
Fail Safe ◽  
The Relationship

BackgroundAn increasing number of studies have investigated delay discounting (DD) in relation to obesity, but with mixed findings. This meta-analysis synthesized the literature on the relationship between monetary and food DD and obesity, with three objectives: (1) to characterize the relationship between DD and obesity in both case–control comparisons and continuous designs; (2) to examine potential moderators, including case–control v. continuous design, money v. food rewards, sample sex distribution, and sample age (<18 v. >18 years); and (3) to evaluate publication bias.MethodFrom 134 candidate articles, 39 independent investigations yielded 29 case–control and 30 continuous comparisons (total n = 10 278). Random-effects meta-analysis was conducted using Cohen's d as the effect size. Publication bias was evaluated using fail-safe N, Begg–Mazumdar and Egger tests, meta-regression of publication year and effect size, and imputation of missing studies.ResultsThe primary analysis revealed a medium effect size across studies that was highly statistically significant (d = 0.43, p < 10−14). None of the moderators examined yielded statistically significant differences, although notably larger effect sizes were found for studies with case–control designs, food rewards and child/adolescent samples. Limited evidence of publication bias was present, although the Begg–Mazumdar test and meta-regression suggested a slightly diminishing effect size over time.ConclusionsSteep DD of food and money appears to be a robust feature of obesity that is relatively consistent across the DD assessment methodologies and study designs examined. These findings are discussed in the context of research on DD in drug addiction, the neural bases of DD in obesity, and potential clinical applications.

scholarly journals The Heart in the Mind: A Systematic Review and Meta-Analysis of the Association Between Theory of Mind and Cardiac Vagal Tone

2021 ◽  
Vol 12 ◽  
Author(s):  
Marta Zammuto ◽  
Cristina Ottaviani ◽  
Fiorenzo Laghi ◽  
Antonia Lonigro
Keyword(s):  
Theory Of Mind ◽  
Effect Size ◽  
Meta Analysis ◽  
Mental States ◽  
Medium Effect ◽  
Behavioral Regulation ◽  
Human Ability ◽  
Medium Effect Size ◽  
Meta Regression Analysis ◽  
The Mind

Theory of mind (ToM) is the human ability to infer the mental states of others in order to understand their behaviors and plan own actions. In the past decades, accumulating evidence has shown that heart rate variability (HRV), an index of parasympathetic control of the heart, is linked to behavioral regulation, social competence, and social cognition abilities, all implicated—to some extent—in ToM. This study aims to systematically review and meta-analyze the available studies, investigating the relation between ToM and HRV in typically developing people. Six studies were eligible for the meta-analysis, yielding a significant association between HRV and ToM of a small-to-medium effect size (g = 0.44). This result was not influenced by publication bias. Due to the small number of studies eligible for the meta-analysis, it was not possible to test for the effect of categorical moderators. The moderating role of sex and quality of the studies was examined by meta-regression analysis. Moderation analysis did not yield any significant effect; however, at a descriptive level, studies yielding the largest effect size were characterized by the use of high frequency-HRV assessment at rest and the Reading the Mind in the Eyes Test to evaluate ToM abilities. The results preliminarily suggest that tonic HRV might be used as an indicator of the ability to understand the content of mind of others.

A Meta-Analysis on the Efficacy of Exposure-Based Treatment in Anxiety Disorders: Implications for Disgust

2020 ◽  
Vol 20 (2) ◽  
pp. 31-49
Author(s):  
Simona A. PASCAL ◽  
Ioana R. PODINA ◽  
Cătălin NEDELCEA
Keyword(s):  
Anxiety Disorders ◽  
Emotional Distress ◽  
Effect Size ◽  
Meta Analysis ◽  
Medium Effect ◽  
Small Effect Size ◽  
Medium Effect Size ◽  
Exposure Sessions ◽  
And Gender ◽  
Meta Analyses

Despite of several meta-analyses indicating that exposure-based treatments (EBT) are successful in addressing anxiety and fear symptoms, less is known whether this is also the case for disgust, which also accompanies anxiety disorders. Therefore, the aim of the current meta-analysis was to compare the efficacy of EBT on disgust and anxiety (emotional distress), against control condition. This meta-analysis included a total of eight studies. Overall, there was a medium effect size (g = .57, 95% CI: .26 to .88, p < .001) for emotional distress; a medium effect size for anxiety (g = .79, 95% CI: .24 to 1.34, p = .005), yet a small effect size for disgust (g = .36, 95% CI: .05 to .68, p = .024). These findings prompt that current EBT are not tailored to address disgust symptoms accompanying many forms of anxiety disorders, although literature points more and more to a need in this respect. We also examined potential moderator variables (the year of publication, the number of exposure sessions, age of the sample, and gender composition). Additionally, we discussed several strengths and limitations, one of the most important being the small number of studies regarding the subject and their heterogeneity.

scholarly journals Botulinum Neurotoxin A Intravesical Injections in Interstitial Cystitis/Bladder Painful Syndrome: A Systematic Review with Meta-Analysis

Toxins ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 510 ◽  
Author(s):  
Antonella Giannantoni ◽  
Marilena Gubbiotti ◽  
Vittorio Bini
Keyword(s):  
Systematic Review ◽  
Interstitial Cystitis ◽  
Effect Size ◽  
Botulinum Neurotoxin ◽  
Meta Analysis ◽  
Medium Effect ◽  
Controlled Trials ◽  
Botulinum Neurotoxin A ◽  
Painful Syndrome ◽  
Medium Effect Size

Botulinum neurotoxin A (BoNT/A) appears to be one of the best intravesical treatments for interstitial cystitis/bladder painful syndrome (IC/BPS). We aimed to point out what the evidence is regarding the effects of BoNT/A intravesically injected in patients with IC/BPS. We performed a systematic review of all randomized controlled trials (RCTs) assessing BoNT/A for IC/BPS by using Medline, EMBASE, CINAHL, CENTRAL and MetaRegister of Controlled Trials. Standardized mean differences (SMD) were extracted from the available trials and combined in a meta-analysis applying a random effect model, including heterogeneity of effects. Twelve trials were identified. Significant benefits from BoNT/A injections were detected in: Interstitial Cystitis Symptom Index and Problem Index (ICSI, ICPI) (small to medium effect size: SMD = –0.302; p = 0.007 and –0.430, p = 0.004, respectively); Visual Analog Scale (VAS) for pain and day-time urinary frequency (medium effect size: SMD = –0.576, p < 0.0001 and –0.546, p = 0.013, respectively). A great effect size was detected for post-void residual volume (PVR, SMD = 0.728; p =0.002) although no clinically relevant in most cases. Great heterogeneity was observed in treatments’ methodologies and symptoms assessment. Overall, BoNT/A intravesical injections significantly improve some of the most relevant symptoms affecting IC/BPS patients.

scholarly journals Variables related to self-leadership of Korean nursing students: A systematic review and meta-analysis

2020 ◽  
Vol 26 (3) ◽  
pp. 213-224
Author(s):  
Myung Hee Cho ◽  
In Ja Jung ◽  
Mi Kyung Park
Keyword(s):  
Nursing Students ◽  
Effect Size ◽  
Meta Analysis ◽  
Individual Characteristics ◽  
Medium Effect ◽  
Follow Up Study ◽  
Medium Effect Size ◽  
Professional Self ◽  
Highly Correlated

Purpose: This study considers the variables related to self-leadership of Korean nursing students and verifies the results of precedent studies through meta-analysis.Methods: This study selected a total of 48 precedent studies regarding the investigation of the correlation between variables related to self-leadership of nursing students conducted between 2009 and 2019 and carried out a meta-analysis.Results: For the effect size of variables related to self-leadership of nursing students, individual characteristics had a medium effect size (ESr=.49) and the effect size was larger for meta-cognition (ESr=.65), emotional intelligence (ESr=.58), and self-efficacy (ESr=.54). The characteristics of nursing competency (ESr=.45) also had a medium effect size and the effect size was larger for professional self-concept (ESr=.60), social support (ESr=.58), and critical thinking (ESr=.56). This result shows that individual characteristics were highly correlated with self-leadership compared to the characteristics of nursing competency.Conclusion: This study is significant in that it verified the effect of variables related to self-leadership and presented the direction and preliminary data for a follow-up study. It is necessary to include variables considering individual characteristics in the development of an educational program for improving self-leadership in the future.

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