Gjalt-Jorn Ygram Peters

Gjalt-Jorn Ygram Peters
Open Universiteit Nederland | OU · Department of Psychology

PhD.

About

96
Publications
29,559
Reads
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4,063
Citations
Introduction
In my work I combine four domains I like to work in: -- behavior change (or, more broadly, health psychology; even more broadly, psychology); -- meta-analyses, qualitative research & quantitative research (or, more broadly, doing research in general); -- giving trainings and teaching. -- coding websites (or, more broadly, programming; even more broadly, being involved in ICT development projects); I combine these domains in my work at the Open University and for my company Greater Good.
Additional affiliations
November 2011 - present
Open Universiteit Nederland
Position
  • Professor (Assistant)
January 2009 - December 2012
Maastricht University
Description
  • A post-doc project about fear appeals; see http://fearappeals.com for the publications that came out of this project.

Publications

Publications (96)
Article
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Background: Ecstasy (3,4-methylenedioxymethamphetamine (MDMA)) has a relatively low harm and low dependence liability but is scheduled on List I of the Dutch Opium Act ('hard drugs'). Concerns surrounding increasing MDMA-related criminality coupled with the possibly inappropriate scheduling of MDMA initiated a debate to revise the current Dutch ec...
Article
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Background Self-identity has frequently been proposed as a useful addition to the Theory of Planned Behavior; yet Fishbein and Ajzen decided to not include self-identity when they published that theory’s successor, the Reasoned Action Approach. One of their reasons for exclusion is the lack of clear conceptual independence, as manifested in self-id...
Article
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Experimental tests of interventions need to have sufficient sample size to constitute a robust test of the intervention’s effectiveness with reasonable precision and power. To estimate the required sample size adequately, researchers are required to specify an effect size. But what effect size should be used to plan the required sample size? Variou...
Article
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The article describes a position statement and recommendations for actions that need to be taken to develop best practices for promoting scientific integrity through open science in health psychology endorsed at a Synergy Expert Group Meeting. Sixteen Synergy Meeting participants developed a set of recommendations for researchers, gatekeepers, and...
Article
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Objective: The Celebrate Safe approach is a collaboration between public health organisations and music event/venue organisers to encourage health promotion interventions in nightlife settings and at music events. The purpose of this study was to evaluate the Celebrate Safe approach with regard to its impact on use of ear plugs among visitors of m...
Article
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Background: Since desk-dominated work environments facilitate sedentary behavior, office workers sit for 66% of their working days and only 8% succeed in interrupting their prolonged periods of sitting within the first 55 minutes. Yet stretches of long and uninterrupted sitting increase the likelihood of several chronic metabolic and cardiovascular...
Article
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Objective: Although basing conclusions on confidence intervals for effect size estimates is preferred over relying on null hypothesis significance testing alone, confidence intervals in psychology are typically very wide. One reason may be a lack of easily applicable methods for planning studies to achieve sufficiently tight confidence intervals. T...
Article
Introduction Fetal alcohol spectrum disorders (FASD) is an important preventable public health concern, associated to a number of common pediatric problems such as incontinence. Little is known about the prevalence and presentation of incontinence in FASD, which hinders effective management. Objective The aim of the present study was to investigat...
Preprint
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Moderated mediation analysis assumes that the effect of a predictor on a dependent variable is mediated by one or more mediators and that the indirect paths in this mediation are moderated. Moderation can take place on the effect of the predictor on the mediators, or on the effect of the mediators on the dependent variable. In this tutorial we will...
Preprint
BACKGROUND Since desk-dominated work environments facilitate sedentary behavior, office workers sit for 66% of their working days and only 8% succeed in interrupting their prolonged periods of sitting within the first 55 minutes. Yet stretches of long and uninterrupted sitting increase the likelihood of several chronic metabolic and cardiovascular...
Article
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The General Data Protection Regulation (GDPR) is the new European Union-wide (EU) law on data protection, which is a great step towards more comprehensive and more far-reaching protection of individuals' personal data. In this editorial, we describe why and how we – as researchers within the field of health psychology – should care about the GDPR....
Article
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Background Unbearable suffering is a key criterion in legally granting patients' euthanasia requests in Belgium yet a generally accepted definition of unbearable suffering remains elusive. The ability to understand and assess unbearable suffering is essential, particularly in patients with psychiatric conditions, as the underlying causes of these c...
Article
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Objectives Fetal alcohol spectrum disorders (FASD) is a worldwide problem. Maternal alcohol consumption is an important risk factor for FASD. It remains unknown which alcohol consumption patterns most strongly predict FASD. The objective of this study was to identify these. Design Systematic literature review. Methods We searched in PubMed, Psych...
Article
Many analytical approaches to single-case data assume either linear effects (regression-based methods) or instant effects (mean-based methods). Neither assumption is realistic; therefore, these approaches’ assumptions are often violated. In this article, we propose modeling curvilinear effects to appropriately parametrize the characteristics of sin...
Article
Authors’ reply - Volume 212 Issue 4 - Monica Verhofstadt, Kenneth Chambaere, Kurt Audenaert, Lieve Thienpont, Gjalt-Jorn Ygram Peters
Article
Authors' reply - Volume 212 Issue 3 - Monica Verhofstadt, Kenneth Chambaere, Lieve Thienpont, Gjalt-Jorn Y. Peters
Article
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Use of fear appeals assumes that when people are emotionally confronted with the negative effects of their behavior they will change that behavior. That reasoning is simple and intuitive, but only true under specific, rare circumstances. Risk-perception theories predict that if people will experience a threat, they want to counter that threat. Howe...
Preprint
The paper shows how a logistic curve can be used to analyze single case data. The technique is explained and compared with the piece-wise regression model. Easy to use software R is also explained and made available.
Article
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Background: Overweightness and obesity represent a high burden on well-being and society. Strength training has positive effects on body composition and metabolic health for people who are overweight or obese. The evidence for psychological effects of strength exercises is unclear. Objective: The aim of this study was to assess the psychological...
Article
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Background The concept of ‘unbearable suffering’ is central to legislation governing whether euthanasia requests may be granted, but remains insufficiently understood, especially in relation to psychiatric patients. Aims To provide insights into the suffering experiences of psychiatric patients who have made a request for euthanasia. Method Testimo...
Article
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We argue that the active ingredients of behaviour change interventions, often called behaviour change methods or techniques (BCTs), can usefully be placed on a dimension of psychological aggregation. We introduce evolutionary learning processes (ELPs) as fundamental building blocks that are on a lower level of psychological aggregation than behavio...
Article
Objectives: Hardcore smokers have smoked for many years and do not intend to quit. They also seem unreceptive to information about smoking cessation. We developed a 30-min, tailored web-based intervention that includes motivational interviewing principles. It aims to increase hardcore smokers' intention to quit and their receptivity to information...
Article
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When developing an intervention aimed at behavior change, one of the crucial steps in the development process is to select the most relevant social-cognitive determinants. These determinants can be seen as the buttons one needs to push to establish behavior change. Insight into these determinants is needed to select behavior change methods (i.e., g...
Article
Introduction Fetal alcohol spectrum disorders (FASD) are one of the leading preventable causes of intellectual disabilities (ID). Not much is known about the topic of pediatric incontinence related to FASD, for example nocturnal enuresis (NE), daytime urinary incontinence (DUI), and fecal incontinence (FI). So far, incontinence problems have been e...
Article
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The instrument of scientific publishing, originally a necessary tool to enable development of a global science, has evolved relatively little in response to technological advances. Current scientific publishing practices incentivize a number of harmful approaches to research. Health Psychology Bulletin was founded to address these issues. Health Ps...
Article
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Health psychology aims to explain and change a wide variety of behaviours, and to this end has developed a plethora of theories. Several attempts have been undertaken to build integrative theories, and some even strive for a Theory of Everything. We argue against these efforts, arguing that instead, adopting a stance that may be called ‘pragmatic n...
Conference Paper
Background: Fetal Alcohol Spectrum Disorders (FASD) is an umbrella term for one of the leading preventable forms of mental retardation affecting individuals and societies worldwide. Alcohol and its interference with the development of the fetus and child are complex and highly variable. The aim of the present is to assess the current state of the a...
Article
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Purpose of Review The objective of the current contribution is to propose an evidence-based, six-step approach to develop effective programs for prevention of fetal alcohol spectrum disorders. Recent Findings Despite widespread campaigns aimed to reduce prenatal alcohol exposure, the number of affected children continues to be high. Current strate...
Poster
Fetal Alcohol Spectrum Disorders (FASD) refers to a spectrum of disorders caused by prenatal alcohol consumption. FASD is a neglected problem in the field of Intellectual Disability (ID). Remarkable, because it is hundred percent preventable. Our research focusses on a systematic approach for prevention and clinical management of FASD. The current...
Conference Paper
Full-text available
Background: Fetal Alcohol Spectrum Disorders (FASD) refers to a spectrum of disorders caused by prenatal alcohol consumption. Alcohol consumption during pregnancy and its interference with the development of the fetus and child is complex and highly variable. However, little is known regarding which alcohol consumption patterns most strongly predic...
Conference Paper
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Aim: To explore somatic healthcare utilisation patterns among people with intellectual disabilities (ID) 55 years and older living in Sweden in comparison with the general population. Method: The ID group (n = 7936) comprised people with ID who were 55 years and older in 2012. A general population sample (n = 7936) was age- and sexmatched. The samp...
Article
Background: Although fetal alcohol spectrum disorders (FASD) affect communities worldwide, little is known about its prevalence. The objective of this study was to provide an overview of the global FASD prevalence. Methods: We performed a search in multiple electronic bibliographic databases up to August 2015, supplemented with the ascendancy an...
Article
Little is known about how contextual factors influence psychosocial determinants of travel mode choice. The reported study examined the effect of organizational sector and geographical region on an Extended Theory of Planned Behavior (TPB) model of commuting travel mode choice. Multigroup structural equation model analyses were conducted to test fo...
Article
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Cronbach's alpha is a commonly reported estimate to assess scale quality in health psychology and related disciplines. In this paper we argue that alpha is an inadequate estimate for both validity and reliability - two key elements of scale quality. Omega is a readily available alternative that can be used for both interval and ordinal data. More i...
Conference Paper
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Background: Alcohol use during pregnancy is one of the leading preventable causes of intellectual or developmental disability. This situation clearly warrants intervention. The complexity of intervention development concerning FASD is overlooked in health promotion. Evidence-based health promotion intervention aimed at the field of FASD is a comple...
Article
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Samenvatting De ontwikkeling van het ongeboren kind kan ernstig in gevaar worden gebracht door alcoholgebruik tijdens de zwangerschap. Deze prenatale blootstelling aan alcohol kan leiden tot levenslange lichamelijke afwijkingen, gedragsstoornissen en cognitieve beperkingen. De Foetaal Alcohol Spectrum Stoornis (FASD) treft alle samenlevingen en is...
Article
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In this paper, we introduce the IM taxonomy of behavior change methods and its potential to be developed into a coding taxonomy. That is, although IM and its taxonomy of behavior change methods are not in fact new, because IM was originally developed as a tool for intervention development, this potential was not immediately apparent. Second, in exp...
Conference Paper
Background: Alcohol use during pregnancy is one of the leading preventable causes of intellectual or developmental disability. FASD is the non-diagnostic umbrella term used to characterize the full range of damage caused by prenatal alcohol exposure, varying from mild to severe, and encompassing a broad array of physical defects and cognitive, beha...
Article
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Background A wide range of diverse and inconsistent terminology exists in the field of knowledge translation. This limits the conduct of evidence syntheses, impedes communication and collaboration, and undermines knowledge translation of research findings in diverse settings. Improving uniformity of terminology could help address these challenges....
Data
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Threatening communication is a widely applied method in behavior change interventions, which at the same time has been heavily criticized in the psychological literature. The current paper describes a study of the reasons for this persistent wide application of threatening communication. We conducted qualitative interviews with 33 key actors in beh...
Article
Fear arousal is widely used in persuasive campaigns and behavioral change interventions. Yet, experimental evidence argues against the use of threatening health information. The authors reviewed the current state of empirical evidence on the effectiveness of fear appeals. Following a brief overview of the use of fear arousal in health education pra...
Article
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Substantial energy savings can be achieved by reducing energy use in office buildings. The reported study used a Theory of Planned Behavior (TPB) model extended with perceived habit to explain office energysaving behaviors. One aim was to examine if organizational contextual variability independently predicted office energy-saving behaviors over an...
Article
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From a corporate social responsibility perspective, there are many reasons to promote teleconference use as an alternative to business travel. The present study examines psychosocial and organizational factors relevant to teleconference use. We tested an extended Theory of Planned Behavior model of teleconference use among office workers of four or...
Article
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There is a need to consolidate the evidence base underlying our toolbox of methods of behaviour change. Recent efforts to this effect have conducted meta-regressions on evaluations of behaviour change interventions, deriving each method’s effectiveness from its association to intervention effect size. However, there are a range of issues that raise...
Article
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The European Health Psychologist ehps.net/ehp Many health psychologists are involved with behaviour change, be it through developing interventions, studying ways to change behaviour or explaining why people engage in risk and health behaviors. Therefore, much of our communication is concerned with the primary research related to behaviour change. T...
Article
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An analysis of individual and organizational determinants of proenvironmental work-related travel behavior, and their interactions, is presented. Interviews and focus groups were conducted with office workers from four organizations in two Dutch provinces. Environmentally-relevant behavior related to commutes and business trips (i.e. travel frequen...
Article
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Despite decades of research, consensus regarding the dynamics of fear appeals remains elusive. A meta-analysis was conducted that was designed to resolve this controversy. Publications that were included in previous meta-analyses were re-analysed, and a number of additional publications were located. The inclusion criteria were full factorial ortho...
Article
The Dutch Government intends to make graphic images on cigarette packages mandatory. However, contrary to other policy measures to reduce smoking, health warnings do not work. There is no acceptable evidence in favour of graphic images and behaviour change theories suggest methods of change that improve skills, self-efficacy and social support. Thu...
Article
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In onze vorige bijdrage 1 hebben we uitgelegd dat angstaanjagende voorlichting nog veel wordt gebruikt, maar niet effectief is. Kort samengevat: onze metaanalyse2 toont aan dat hoge dreiging alleen tot gedragsverandering leidt bij hoge waargenomen effectiviteit (‘efficacy’), en hoge effectiviteit alleen tot gedragsverandering leidt bij hoge dreigin...
Article
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In de publieke gezondheidzorg willen we terecht evidence-based werken. Deze evidentie bestaat idealiter uit reviews en meta-analyses. Tegelijkertijd worden uitkomsten van dergelijke kennissyntheses niet altijd ter harte genomen. Onze recente meta-analyse over angstaanjagende voorlichting, gepubliceerd in Health Psychology Review, 1 heeft de discuss...
Article
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Rathi and colleagues provide insight into clinical trialists' opinions and experiences of sharing clinical trial data. 1 We would like to raise two related matters. Firstly, this study and previous studies cited within are limited to sharing data. We suggest that questionnaires, intervention manuals, analysis scripts (such as syntax files), output...
Article
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The way we currently organise and report research retards behavioural science. This brief article provides an explanation of how we are holding back scientific progress, how this situation developed, and how current practice is justified. We also recommend practical, low-cost solutions, which would facilitate scientific advances.
Article
A review of empirical studies on proenvironmental behaviors in organizational contexts is presented. Twenty-one studies met the inclusion criteria. Quantitative effect sizes were compared where statistics were available and research designs were comparable. Characteristics of the dependent variable and the targeted organiza-tional (sub)populations...