Hans IJzerman's research while affiliated with Institut Universitaire de France and other places

Publications (158)

Preprint
To understand whether and how temperature regulation contributes to interpersonal relationships, we need to study them on a daily basis. To do so, we need accurate sensors to measure frequently. In this study, we aim to validate the PurpleXus sensor for skin temperature measurement. It’s a newer, potentially more accurate, and less invasive thermal...
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Liu, Wang, and Van Lange (2022) have published a study that “replicated earlier findings that prosociality was associated with a greater level of secure attachment and a lower level of avoidant attachment” and that “prosociality was positively related to the number of siblings, especially sisters, as discovered by Study 3 of the original study”. Th...
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Significance Communicating in ways that motivate engagement in social distancing remains a critical global public health priority during the COVID-19 pandemic. This study tested motivational qualities of messages about social distancing (those that promoted choice and agency vs. those that were forceful and shaming) in 25,718 people in 89 countries...
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Among animals, natural selection has resulted in a broad array of behavioural strategies to maintain core body temperature in a relatively narrow range. One important temperature regulation strategy is social thermoregulation , which is often done by warming the body together with conspecifics. The literature suggests that the same selection pressu...
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When psychologists attend to Africa, they usually test whether theories and concepts developed in North America and Europe generalize to Africa. Psychology would be enriched by focusing on Africa on its own terms.
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When psychologists attend to Africa, they usually test whether theories and concepts developed in North America and Europe generalize to Africa. Psychology would be enriched by focusing on Africa on its own terms.
Preprint
We aim to replicate a study by IJzerman et al. (2012), which concluded that the experimental condition of social exclusion (vs. inclusion) in the Cyberball computer game decreases peripheral index finger temperature, but did so at 67.2% power (N=41), in a single lab in a colder country (the Netherlands), yet concluded generalizability. The study re...
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For more than a decade, research in psychology has been struggling to replicate many well-known and highly cited studies. This replication crisis has been the genesis for the emergence of many Big Team Science projects. One early contributor to the Big Team Science movement is the Collaborative Replication and Education Project (CREP), a large-scal...
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Although replication is a central tenet of science, direct replications are rare in psychology. This research tested variation in the replicability of thirteen classic and contemporary effects across 36 independent samples totaling 6,344 participants. In the aggregate, ten effects replicated consistently. One effect – imagined contact reducing prej...
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This dataset is from the Many Labs Replication Project [1] in which 13 effects were replicated across 36 samples and over 6,000 participants. Data from the replications are included, along with demographic variables about the participants and contextual information about the environment in which the replication was conducted. Data were collected in...
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This manuscript contains our responses to several commentaries about the Many Labs Project (Klein et al., 2014).
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Central to interventions to improve the quality of romantic relationships is its measurement. Yet, to what degree is the concept of relationship quality well-defined, and, importantly, well-measured? In the present article, the authors conducted a comprehensive search of instruments measuring relationship quality in ProQuest, Web of Science, and Sc...
Article
La qualité de la recherche scientifique s’évalue non seulement par son impact positif sur le développement socio-économique et le bien-être humain, mais également par sa contribution à l’élaboration des connaissances scientifiques valides et fiables. De ce fait, les chercheurs, quelle que soit leur discipline scientifique, sont censés adopter des p...
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This meta-analysis explored whether being in nature and emotional social support are effective in reducing levels of stress through a Registered Report. We retrieved all the relevant articles that investigated a connection between one of these two strategies and various components of stress (physiological, affective and cognitive) as well as affect...
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Do colored backgrounds lead to polarized judgments? Zarkadi and Schnall (2013) found in their Study 1 that, indeed, exposing participants to a black-and-white (versus other colored) background polarized participants’ judgments in a moral dilemma task. This study supported a moral intuitionist model of moral judgment and lent further support to so-c...
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We conducted a pre-registered meta-analysis to appraise available evidence on two stress regulation strategies: Self-administered mindfulness meditation and heart rate variability biofeedback. We used a combination of keywords to find as many experimental and observational studies as possible, all of which highlighted a link between the two strateg...
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The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about...
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Full-text available
The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about...
Article
Full-text available
The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about...
Preprint
Improving the generalizability of psychology findings to a culture requires sampling participants in that culture. Yet few psychology studies sample Africans. We believe we can expand the capacity of African psychology researchers by giving them freely available, cutting-edge research tools and workflows. We used a training method developed by the...
Preprint
Improving the generalizability of psychology findings to a culture requires sampling participants in that culture. Yet few psychology studies sample Africans. We believe we can expand the capacity of African psychology researchers by giving them freely available, cutting-edge research tools and workflows. We used a training method developed by the...
Article
Tearful crying is a ubiquitous and likely uniquely human phenomenon. Scholars have argued that emotional tears serve an attachment function: Tears are thought to act as a social glue by evoking social support intentions. Initial experimental studies supported this proposition across several methodologies, but these were conducted almost exclusively...
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Full-text available
Previous studies have indicated that temperature regulation is related to social behavior (for an overview, see IJzerman et al., 2015; IJzerman & Hogerzeil, 2017). However, precise causal relationships between temperature and social behaviors are unclear. These links may be better understood by frequently measuring temperature in daily life and map...
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Spurred by a crisis in their confidence in past findings, psychology in North America, Europe, and Australia has been undergoing a credibility revolution, which has spurred the development and popularization of open science practices to improve the research process. Alongside this development, a broad array of stakeholders have noted that African s...
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The authors conducted a close replication of a study by Georgiou et al (2020), who found amongst 660 (reported in abstract) or 640 (reported in participant section) participants that 1) Covid-19 related conspiracy theory beliefs were strongly related to broader conspiracy theory beliefs, that 2) Covid-19 related conspiracy beliefs were higher in th...
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Rejoinder to Lee, S., & Schwarz, N. (2021). Grounded procedures in mind and society. Behavioral and Brain Sciences, 44(E29). doi:10.1017/S0140525X20000643
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Embodied – or grounded - cognition frameworks assume that human thought is affected by inputs from the bodily modalities and the environment and emerged in response to amodal approaches. But the embodied cognition literature, generally speaking, lacks the formal theorizing that allows for specific predictions about relations between body and mind....
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One key motivating force for bonding across animals is their need to regulate body temperature, also called social thermoregulation. This phenomenon has been extensively documented in animals, but only recently its existence has been suggested in humans. Psychology, however, has been faced with conflicting findings and the social thermoregulation l...
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Currently in psychological science considerable effort is directed towards confirmatory practices. Much less attention has been devoted to how to do exploratory research. In this article, we support researchers in expanding their methodological toolbox by adding one more technique of exploratory research. The majority of this article is a hands-on...
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The pattern of data underlying the successful replications of cleansing effects is improbable and most consistent with selective reporting. Moreover, the meta-analytic approach presented by Lee and Schwarz is likely to find an effect even if none existed. Absent more robust evidence, there is no need to develop a theoretical account of grounded pro...
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Embodied – or grounded - cognition frameworks assume that human thought is affected by inputs from the bodily modalities and the environment and emerged in response to amodal approaches. But the embodied cognition literature, generally speaking, lacks the formal theorizing that allows for specific predictions about relations between body and mind....
Chapter
To cope with changing and unfamiliar situations, individuals process novel information and integrate this information into internal models that were formed through previous experiences. We propose that the continuum of the degree to which people update these internal models when encountering novel information is central to personality dynamics. Per...
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Full-text available
Replication studies in psychological science sometimes fail to reproduce prior findings. If these studies use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data-collecti...
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This document estimates the Psychological Science Accelerator’s study capacity for the 2020-2021 academic year. As described in our Study Capacity Policy, study capacity is determined by the PSA’s data collection capacity, or the amount and kind of participant data the PSA can collect in a given year, and its administrative capacity, or its ability...
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In a test of their global-/local-processing-style model, Förster, Liberman, and Kuschel (2008) found that people assimilate a primed concept (e.g., “aggressive”) into their social judgments after a global prime (e.g., they rate a person as being more aggressive than do people in a no-prime condition) but contrast their judgment away from the primed...
Preprint
Full-text available
Replications in psychological science sometimes fail to reproduce prior findings. If replications use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data collection peer...
Preprint
Full-text available
Tearful crying is a ubiquitous and likely uniquely human phenomenon. The persistence of this behavior throughout adulthood has fascinated and puzzled many researchers. Scholars have argued that emotional tears serve an attachment function: Tears are thought to act as a social glue by triggering social support intentions. Initial experimental studie...
Article
Full-text available
Social and behavioural scientists have attempted to speak to the COVID-19 crisis. But is behavioural research on COVID-19 suitable for making policy decisions? We offer a taxonomy that lets our science advance in ‘evidence readiness levels’ to be suitable for policy. We caution practitioners to take extreme care translating our findings to applicat...
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Full-text available
The pattern of data underlying the successful replications of cleansing effects is improbable and most consistent with selective reporting. Moreover, the meta-analytic approach presented by Lee and Schwarz is likely to find an effect even if none existed. Absent more robust evidence, there is no need to develop a theoretical account of grounded pro...
Preprint
Among animals, natural selection has resulted in a broad array of behavioral strategies to maintain core body temperature in a relatively narrow range. These strategies include social thermoregulation, the use of con-specifics to warm the body through activities like huddling. We suspected that the same selection pressures that apply to other anima...
Preprint
Progress in psychology has been frustrated by challenges concerning replicability, generalizability, strategy selection, inferential reproducibility, and computational reproducibility. Although often discussed separately, we argue that these five problems share a common cause: insufficient investment of resources into the typical psychology study....
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Full-text available
The quality of scientific research is assessed not only by its positive impact on socio-economic development and human well-being, but also by its contribution to the development of valid and reliable scientific knowledge. Thus, researchers regardless of their scientific discipline, are supposed to adopt research practices based on transparency and...
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Full-text available
Psychological scientists have attempted to speak to the COVID-19 crisis. Psychology research on COVID-19, we argue, is unsuitable for making policy decisions. We offer a taxonomy that lets our science advance in Evidence Readiness Levels to be suitable for policy; we caution practitioners to take extreme care translating our findings to application...
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Full-text available
The facial feedback hypothesis suggests that an individual’s subjective experience of emotion is influenced by their facial expressions. Researchers, however, currently face conflicting narratives about whether this hypothesis is valid. A large replication effort consistently failed to replicate a seminal demonstration of the facial feedback hypoth...
Article
Full-text available
Tearful crying is a ubiquitous and mainly human phenomenon. The persistence of this behavior throughout adulthood has fascinated and puzzled many researchers. Scholars have argued that emotional tears serve an attachment function: Tears are thought to act as a social glue that binds individuals together and triggers social support intentions. Initi...
Preprint
Full-text available
Tearful crying is a ubiquitous and mainly human phenomenon. The persistence of this behavior throughout adulthood has fascinated and puzzled many researchers. Scholars have argued that emotional tears serve an attachment function: Tears are thought to act as a social glue that binds individuals together and triggers social support intentions. Initi...
Preprint
Full-text available
We propose the first Registered Report examining social co-thermoregulation in humans, a widely studied phenomenon in ecology whereby animals help regulate body heat through conspecifics (for example, by huddling). Participants’ peripheral body temperature will be measured continuously while they view photos of their romantic partner, or strangers,...
Chapter
Full-text available
In this chapter, we compare deep learning and classical approaches for detection of baby cry sounds in various domestic environments under challenging signal-to-noise ratio conditions. Automatic cry detection has applications in commercial products (such as baby remote monitors) as well as in medical and psycho-social research. We design and evalua...
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In this chapter, we compare deep learning and classical approaches for detection of baby cry sounds in various domestic environments under challenging signal-to-noise ratio conditions. Automatic cry detection has applications in commercial products (such as baby remote monitors) as well as in medical and psycho-social research. We design and evalua...
Article
Full-text available
Attachment theory was built around the idea that infants rely on others to survive, and it is often forgotten that survival hinged on coping with environmental demands. Adult attachment reports have instead been organized around people’s subjective experience of safety and security in relationships. To resolve the gap between infant’s physical need...
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Full-text available
Over the last ten years, Oosterhof and Todorov’s valence-dominance model has emerged as the most prominent account of how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social judgments of faces. Because this model has primarily been developed and tested in Western regions, it is unclear w...
Preprint
Replications in psychological science sometimes fail to reproduce prior findings. If replications use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data collection peer...
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Full-text available
We detail the philosophy of our lab, which serves as a general workflow and also a lab manual describing expectations and responsibilities. Updated once per year based on what is/isn't working.
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In the Human Penguin Project (N = 1755), 15 research groups from 12 countries collected body temperature, demographic variables, social network indices, seven widely-used psychological scales and two newly developed questionnaires (the Social Thermoregulation and Risk Avoidance Questionnaire (STRAQ-1) and the Kama Muta Frequency Scale (KAMF)). They...
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We report a replication and extension of a finding from Studies 1 and 2 of Van Lange et al.'s influential paper (Van Lange et al. 1997 J. Pers. Soc. Psychol. 73, 733-746. (doi:10.1037/0022-3514. 73.4.733)), which showed an association between Social Value Orientation (SVO) and attachment security. We report a close replication but with measures of...
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We describe the data management bylaws for the Psychological Science Accelerator (PSA), a distributed network of laboratories dedicated to completing large-scale collaborative behavioral science projects. Our bylaws are organized around the principles of ethical data use, security, accuracy, usability, transparency. We describe how these embodied t...
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Full-text available
The present article reports the results of a meta-analysis of nine student replication projects of Elliot et al.’s (2010) findings from Experiment 3, that women were more attracted to photographs of men with red borders (total 'n' = 640). The eight student projects were part of the Collaborative Replication and Education Project (CREP; https://osf....
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Full-text available
We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories....
Preprint
Full-text available
We conducted preregistered replications of 28 classic and contemporary published findings with protocols that were peer reviewed in advance to examine variation in effect magnitudes across sample and setting. Each protocol was administered to approximately half of 125 samples and 15,305 total participants from 36 countries and territories. Using co...
Article
We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories....
Preprint
Full-text available
In the Human Penguin Project (N = 1755), 15 research groups from 12 countries collected body temperature, demographic variables, social network indices, seven widely-used psychological scales and two newly developed questionnaires (the Social Thermoregulation and Risk Avoidance Questionnaire (STRAQ-1) and the Kama Muta Frequency Scale (KAMF)). They...
Article
Body temperature regulation is of crucial importance for nonhuman and human animals. Because other animals are crucial in helping to regulate body temperature, temperature differences likely determine how humans think about their social environment. Since 2008, the psychological literature on social thermoregulation has flourished with approximatel...
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Full-text available
Psychological science is in a transitional period: Many findings do not replicate and theories appear not as robust as previously presumed. We suspect that a main reason for theories not appearing as robust is because they are too simple. In this paper, we provide an important step towards this transition in the field of interpersonal relationship...
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Full-text available
Social thermoregulation theory posits that modern human relationships are pleisiomorphically organized around body temperature regulation. In two studies (N = 1755) designed to test the principles from this theory, we used supervised machine learning to identify social and non-social factors that relate to core body temperature. This data-driven an...
Preprint
Attachment theory was built around the idea that infants rely on others to survive, and often, forgotten, that survival hinged on coping with environmental demands. Adult attachment reports have instead been organized around people’s subjective experience of safety and security in relationships. To resolve the gap between infant’s physical needs an...
Article
Full-text available
Concerns about the veracity of psychological research have been growing. Many findings in psychological science are based on studies with insufficient statistical power and nonrepresentative samples, or may otherwise be limited to specific, ungeneralizable settings or populations. Crowdsourced research, a type of large-scale collaboration in which...
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Zwaan et al. integrated previous articles to promote making replications mainstream. We wholeheartedly agree. We extend their discussion by highlighting several existing initiatives – the Replication Recipe and the Collaborative Education and Research Project (CREP) - which aim to make replications mainstream. We hope this exchange further stimulat...