Are Yawns really Contagious? A Critique and Quantification of Yawn Contagion

Many diverse species yawn, suggesting ancient evolutionary roots. While yawning is widespread, the observation of contagious yawning is most often limited to apes and other mammals with sophisticated social cognition. This has led to speculation on the adaptive value of contagious yawning. Among this speculation are empirical and methodological assumptions demanding re-examination. In this paper we demonstrate that if yawns are not contagious, they may still appear to be so by way of a perceptual pattern-recognition error. Under a variety of conditions (including the assumption that yawns are contagious) we quantify (via models) the extent to which the empirical literature commits Type-1 error (i.e., incorrectly calling a spontaneous yawn ‘contagious’). We report the results of a pre-registered behavioural experiment to validate our model and support our criticisms. Finally, we quantify – based on a synthesis of behavioural and simulated data – how ‘contagious’ a yawn is by describing the size of the influence a ‘trigger’ yawn has on the likelihood of a consequent yawn. We conclude by raising a number of empirical and methodological concerns that aid in resolving higher-order questions regarding the nature of contagious yawning, and make public our model to help aid further study and understanding

Exploring the Pathways Between Transformative Group Experiences and Identity Fusion.

A growing body of evidence suggests that two distinct forms of group alignment are possible: identification and fusion (the former asserts that group and personal identity are distinct, while the latter asserts group and personal identities are functionally equivalent and mutually reinforcing). Among highly fused individuals, group identity taps directly into personal agency and so any attack on the group is perceived as a personal attack and motivates a willingness to fight and possibly even die as a defensive response. As such, identity fusion is relevant in explaining violent extremism, including suicidal terrorist attacks. Identity fusion is theorized to arise as a result from experiences which are (1) perceived as shared and (2) transformative, however evidence for this relationship remains limited. Here, we present a pre-registered study in which we examine the role of transformativeness and perceived sharedness of group-defining events in generating identity fusion. We find that both of these factors are predictive of identity fusion but that the relationship with transformativeness was more consistent than perceived sharedness across analyses in a sample of Indonesian Muslims

Examining memory for ritualized gesture in complex causal sequences

Abstract: Humans have created and maintained an exponentially large and sophisticated behavioral corpus over evolutionary time. In no small part this was achieved due to our tendency to imitate behaviours rather than to emulate outcomes. This tendency, however, can lead to inefficiency and redundancy in our behavioral repertoires. Drawing on evidence from multiple fields of psychology, we propose two novel competing hypotheses. The ‘catalyst hypothesis’ suggests that low (but not high) proportions of ritualized gesture in instrumental action sequences will improve subsequent recall of the entire action sequence (without itself enhancing the instrumental utility of the sequence). Conversely, the ‘cost hypothesis’ suggests that increasing proportions of ritualized gesture will impair recall, due to the introduction of cognitive load. The null hypothesis states that ritualized gestures are neither beneficial nor costly. In a pre‐registered experiment, we presented participants with multiple versions of two complicated 2‐minute action sequences in which we varied the proportion of ritualized gesture. We then quantified the influence ritualized gesture had on recall for individuals gestures, overall outcomes, and described detail. We found clear evidence that high proportions of ritualized gestures impair recall for individual gestures and overall success, and weak evidence that low proportions increase overall success. At present, we may reject the null, but cannot rule out either of our competing hypotheses. We discuss potential implications for cultural evolution, and generate competing predictions that allow for adjudication between Ritual Modes theory (Whitehouse, 2004) and the ‘Cognitive Resource Depletion’ account of Religious Interaction (Schjoedt et al., 2013). All files (including data and syntax) are freely available at https://osf.io/spz68/

The child's pantheon: Children's hierarchical belief structure in real and non-real figures.

To what extent do children believe in real, unreal, natural and supernatural figures relative to each other, and to what extent are features of culture responsible for belief? Are some figures, like Santa Claus or an alien, perceived as more real than figures like Princess Elsa or a unicorn? We categorized 13 figures into five a priori categories based on 1) whether children receive direct evidence of the figure's existence, 2) whether children receive indirect evidence of the figure's existence, 3) whether the figure was associated with culture-specific rituals or norms, and 4) whether the figure was explicitly presented as fictional. We anticipated that the categories would be endorsed in the following order: 'Real People' (a person known to the child, The Wiggles), 'Cultural Figures' (Santa Claus, The Easter Bunny, The Tooth Fairy), 'Ambiguous Figures' (Dinosaurs, Aliens), 'Mythical Figures' (unicorns, ghosts, dragons), and 'Fictional Figures' (Spongebob Squarepants, Princess Elsa, Peter Pan). In total, we analysed responses from 176 children (aged 2-11 years) and 56 adults for 'how real' they believed 13 individual figures were (95 children were examined online by their parents, and 81 children were examined by trained research assistants). A cluster analysis, based exclusively on children's 'realness' scores, revealed a structure supporting our hypotheses, and multilevel regressions revealed a sensible hierarchy of endorsement with differing developmental trajectories for each category of figures. We advance the argument that cultural rituals are a special form of testimony that influences children's reality/fantasy distinctions, and that rituals and norms for 'Cultural Figures' are a powerful and under-researched factor in generating and sustaining a child's endorsement for a figure's reality status. All our data and materials are publically available at https://osf.io/wurxy/

Homo neanderthalensis and the evolutionary origins of ritual in Homo sapiens

There is a large, if disparate, body of archaeological literature discussing specific instantiations of symbolic material culture and the possibility of ritual practices in Neanderthal populations. Despite this attention, however, no single synthesis exists that draws upon cognitive, psychological and cultural evolutionary theories of ritual. Here, we review the evidence for ritual-practice among now-extinct Homo neanderthalensis, as well as the necessary cognitive pre-conditions for such behaviour, in order to explore the evolution of ritual in Homo sapiens. We suggest that the currently available archaeological evidence indicates that Neanderthals may have used ‘ritualization’ to increase the successful transmission of technical knowledge across generations—providing an explanation for the technological stability of the Middle Palaeolithic and attesting to a survival strategy differing from near-contemporary H. sapiens. / This article is part of the theme issue ‘Ritual renaissance: new insights into the most human of behaviours’

Ritual Morphospace Revisited: The form, function, and factor structure of ritual practice

Human rituals exhibit bewildering diversity, from the Mauritian Kavadi to Catholic communion. Is this diversity infinitely plastic or are there some general dimensions along which ritual features vary? We analysed two cross-cultural datasets, one drawn from the anthropological record, and another novel contemporary dataset to examine whether a consistent underlying set of latent dimensions in ritual structure and experiences were detected. First, we conducted a factor analysis on 651 rituals from 74 cultural groups, in which 102 binary variables were coded. We find a reliable set of dimensions emerged, which provide potential candidates for foundational elements of ritual form. Notably, we find that the expression of features associated with dysphoric and euphoric experiences in rituals appear to be largely orthogonal. Second, we follow-up with a pre-registered factor analysis examining contemporary ritual experiences of 779 individuals from Japan, India, and the US. We find supporting evidence that ritual experiences are clustered in relatively orthogonal euphoric, dysphoric, frequency and cognitive dimensions. Our findings suggest there are important regularities in the diversity of ritual expression and experience observed across both time and culture. We discuss the implications of these findings for cognitive theories of ritual and cultural evolution

Homo neanderthalensis and the evolutionary origins of ritual in Homo sapiens

There is a large, if disparate, body of archaeological literature discussing specific instantiations of symbolic material culture and the possibility of ritual practices in Neanderthal populations. Despite this attention, however, no single synthesis exists which draws upon cognitive, psychological, and cultural evolutionary theories of ritual. Here we review the evidence for ritual-practice among now extinct Homo neanderthalensis, as well as the necessary cognitive pre-conditions for such behaviour, in order to explore the evolution of ritual in Homo sapiens. We suggest that the currently available archaeological evidence indicates that Neanderthals may have utilised ‘ritualisation’ to increase the successful transmission of technical knowledge across generations — providing an explanation for the technological stability of the Middle Palaeolithic and attesting to a survival strategy differing from near contemporary Homo sapiens

A comprehensive overview on Kratom

Kratom (Mitragyna speciosa Korth) is a tropical tree, indigenous to South East Asia. Historically, the plant is locally used as a stimulant, a remedy in traditional medicine and in social context. Imported to Western countries, Kratom is classified as a novel psychoactive substance (NPS). A systematic review of the literature on Mitragyna speciosa and its main constituents was carried by our international multidisciplinary group. Results were qualitatively analysed in three main areas of interest: in-vitro and preclinical data on pharmacology and behavioral effects, laboratoristic techniques for identification/characterization, epidemiological/toxicological reports on humans. At present, there is no systematic data on the prevalence of Kratom use in all the native countries, but it seems to be considerable. In South-East Asia, Kratom, even if banned, might be still considered a better option than other illicit drugs, an alternative opioid treatment, a “natural” remedy with no real social stigma attached to its consumption. In parallel, this ethno-drug seems to be popular in Western countries, largely unregulated, easily available on the Internet. Kratom pharmacology appears to be complex, with many alkaloids involved. The subjective effects in humans are very peculiar and seem to be dose-dependent, ranging from psycho-stimulant to sedative-narcotic. Available data on Kratom suggest caution: this psychoactive plant could exhibit a serious harmful potential. Kratom use seems to be associated with drug dependency, development of withdrawal symptoms, craving, serious adverse effects and life-threatening effects in a multidrug-intoxicating scenario. On the other hand, its anxyiolitic, antidepressant and analgesic properties deserve to be further studied

The 21-item Barratt Impulsiveness Scale Revised (BIS-R-21): an alternative three-factor model

Background and aims: Due to its important role in both healthy groups and those with physical, mental and behavioral disorders, impulsivity is a widely researched construct. Among various self-report questionnaires of impulsivity, the Barratt Impulsiveness Scale is arguably the most frequently used measure. Despite its international use, inconsistencies in the suggested factor structure of its latest version, the BIS-11, have been observed repeatedly in different samples. The goal of the present study was therefore to test the factor structure of the BIS-11 in several samples. Methods: Exploratory and confirmatory factor analyses were conducted on two representative samples of Hungarian adults (N 5 2,457; N 5 2,040) and a college sample (N 5 765). Results: Analyses did not confirm the original model of the measure in any of the samples. Based on explorative factor analyses, an alternative three-factor model (cognitive impulsivity; behavioral impulsivity; and impatience/ restlessness) of the Barratt Impulsiveness Scale is suggested. The pattern of the associations between the three factors and aggression, exercise, smoking, alcohol use, and psychological distress supports the construct validity of this new model. Discussion: The new measurement model of impulsivity was confirmed in two independent samples. However, it requires further cross-cultural validation to clarify the content of self-reported impulsivity in both clinical and nonclinical samples