Monday, October 11, 2021

There is vidence suggesting that in martial arts competitions athletes characterized by higher anxiety & harm avoidance may be more likely to lose a fight; cortisol is higher in losers before and in response to a competition

Cortisol, Temperament and Serotonin in Karate Combats: An Evolutionary Psychobiological Perspective. Davide Ponzi, Harold Dadomo, Laura Filonzi, Paola Palanza, Annalisa Pelosi, Graziano Ceresini, Stefano Parmigiani & Francesco Nonnis Marzano. Adaptive Human Behavior and Physiology, Oct 4 2021. https://link.springer.com/article/10.1007%2Fs40750-021-00178-0

Abstract

Objectives: There is evidence suggesting that in martial arts competitions athletes characterized by higher anxiety and harm avoidance may be more likely to lose a fight. This psychological profile has been hypothesized to explain in part the observation that cortisol is higher in losers before and in response to a competition. An important research target that needs further exploration is the identification of phenotypic traits that can be helpful in predicting athletes’ performance. Here we present a brief description of the theoretical bases that drives our research in the evolutionary psychobiology of sports and illustrate preliminary data on the relationship between the 5HTTLPR genotype, salivary cortisol, temperament and competition.

Methods: Sixty-five healthy male non-professional athletes provided saliva samples 10 min before and after a kumite session and filled out the Tridimensional Personality Questionnaire.

Results: Salivary cortisol levels 10 min before the competition were higher in losers and in athletes with the S allele. Temperament was associated with competition outcome and cortisol: losers were characterized by higher scores of harm avoidance and harm avoidance was positively correlated with cortisol levels.

Conclusions: The results confirm previous findings linking temperamental traits, pre-and post- competition physiological stress response with competition outcome in kumite fight. Moreover, they indicate an association between the 5HTTLPR polymorphism and pre-competition salivary cortisol, thus providing a preliminary but non-conclusive evidence on the role played by the 5HTTLPR genotype as a vulnerability factor in sport competition.

Discussion

A crucial challenge for sport scientists is to identify the psychobiological substrates (i.e., personality, genes and hormones) that are associated with athletes’ superior performance. Provided that sports are a ritualized form of competition evolved for access to primary and secondary fitness relevant resources, we expect successful athletes to show a cluster of functionally adapted traits. Natural selection should favor the co-evolution of traits if their covariation has increased animals’ performance throughout their evolutionary past. For example, if a specific type of personality is positively correlated with higher fitness, other traits that share the same genes, either through negative pleiotropy or linkage disequilibrium (Svensson et al., 2021) or physiological bases (Dochtermann, 2011; Kern et al., 2016; McGlothlin & Ketterson, 2008) with the personality trait should be more frequently found in the same individual.

In the present study we were interested to know if winners and losers of a karate fight could be identified by their scores in three different psychobiological traits. We found that salivary cortisol levels 10 min before the competition were higher in athletes that lost the fight, but no differences were found between winners and losers for salivary cortisol reactivity. Athletes that lost the fight had on average higher levels of harm avoidance while no relationships of the 5HTTLPR polymorphism with competition outcome or harm avoidance were found. However, we provide preliminary evidence showing that athletes with the SS genotype might have on average higher pre-competition levels of salivary cortisol, an interesting insight in light of several studies reporting a role played by the 5HTTLPR polymorphism in managing sport anxiety (Petito et al., 20162021; Sanhueza et al., 2016).

Within the animal literature, subjects that tend to win fights are characterized by a cluster of behavioral, physiological and neurobiological characteristics such as higher aggressiveness, higher risk-approach behavior and lower HPAA responses to challenges (Koolhaas et al., 1999; Korte et al., 2005). Currently, there is still an open debate on the role played by cortisol in predicting competition outcome in martial arts (Casto & Edwards, 2016a; Filaire et al., 2009; Jiménez et al., 2012; Papacosta et al., 2016; Parmigiani et al., 20062009; Salvador et al., 2003; Suay et al., 1999). Likewise, the role played by psychological factors such as mood and personality in relation to competition performance and especially on winning and losing has been extensively studied (Casanova et al., 2015; Casto & Edwards, 2016b; Casto et al., 2017; Gonzalez-Bono et al., 1999; Salvador & Costa, 2009; Salvador, 2005; Suay et al., 1999; Zilioli & Watson, 2013), but a direct translation of the evolutionary concept of coping strategies and evolved, correlated traits such as personality and physiological responses has not yet been produced. Our finding that 85% of karate fighters could be predicted to be winners or losers based on their harm avoidance score and pre-competition cortisol levels is very interesting in his regard.

It is important to highlight that the single, pre-competition measure of cortisol of our study cannot unequivocally be considered an anticipatory response of the HPA axis to the competition. Instead, it possible that these higher levels of cortisol found in losers represent a stable trait of those people that experience higher everyday anxiety and stress because of their higher scores of harm avoidance. Some authors have suggested that elevated scores of harm avoidance may predispose individuals to experience psychological distress, fear, anxiety and low mood (Farmer & Seeley, 2009; Trouillet & Gana, 2008) and harm avoidance appears related with the magnitude of HPA axis activation (Tyrka et al., 2008). Thus, perhaps athletes that went on to lose the fight were already stressed out by similar daily hussles unrelated to the karate competition.

Lastly, the 5HTTLPR polymorphism was not predictive of victory or defeat nor of temperament, despite being correlated with pre-competition salivary cortisol. This should not be surprising for several reasons. We should not expect a single candidate gene to be predictive of competition outcome. Specifically in relation to behavioral coping strategies, genetic variation in genes related to other neurotransmitters such as dopamine may be important. In this regard, the dopamine transporter genotype 9/9 and allele 9 that have been reported to be highly frequent in Olympic athletes (Filonzi et al., 2015). However, the effects of candidate genes on personality (and perhaps on behavioral coping strategies) are probably very small, while the role played by many variants with small effects is more likely (Penke & Jokela, 2016). Finally, it is possible that the lack of a correlation between harm avoidance and the s allele could be due by the choice of the personality measure and by the lack of statistical power. In fact, the presence and strength of a SS genotype-anxiety link has been found to depend on the personality measures used and on sample size. For example, the neuroticism dimension of the Big Five personality inventory but not harm avoidance is strongly correlated with the 5HTTLPR polymorphism (Sen et al., 2004). Yet, the possible relationship between harm avoidance and the5HTTLPR polymorphism should not be discarded since a recent study carried out with high level Italian athletes reported that those with higher scores of harm avoidance were more likely to have the s allele (Petito et al., 2021). Perhaps more important, the sample size of our study is a limitation for these kinds of research questions (Miller et al., 2013).

Sunday, October 10, 2021

The etiology of mental disorders is not fully understood, but one likely contributor is perturbations of neurodevelopment; nonright-handedness is a sign of such perturbations, but psychopaths don't show elevated rates of nonright-handedness

Is Psychopathy a Mental Disorder or an Adaptation? Evidence From a Meta-Analysis of the Association Between Psychopathy and Handedness. Lesleigh E. Pullman, Nabhan Refaie, Martin L. Lalumière, DB Krupp. Evolutionary Psychology, October-December 2021: 1–17. DOI: 10.1177/14747049211040447

Abstract: Psychopathy has historically been conceptualized as a mental disorder, but there is growing evidence that it may instead be an alternative, adaptive life history strategy designed by natural selection. Although the etiology of mental disorders is not fully understood, one likely contributor is perturbations affecting neurodevelopment. Nonright-handedness is a sign of such perturbations, and therefore can be used to test these competing models. If psychopathy is a mental disorder, psychopaths should show elevated rates of nonright-handedness. However, an adaptive strategy perspective expects psychopaths to be neurologically healthy and therefore predicts typical rates of nonright-handedness. We meta-analyzed 16 studies that investigated the association between psychopathy and handedness in various populations. There was no difference in the rates of nonright-handedness between community participants high and low in psychopathy. Furthermore, there was no difference between psychopathic and nonpsychopathic offenders in rates of nonright-handedness, though there was a tendency for offenders scoring higher on the Interpersonal/Affective dimension of psychopathy to have lower rates of nonright-handedness, and for offenders scoring higher on the Behavioral dimension of psychopathy to have higher rates of nonright-handedness. Lastly, there was no difference in rates of nonright-handedness between psychopathic and nonpsychopathic mental health patients. Thus, our results fail to support the mental disorder model and partly support the adaptive strategy model. We discuss limitations of the meta-analysis and implications for theories of the origins of psychopathy.

Keywords: Psychopathy, life history, adaptation, mental disorder, handedness


Children from an early age present a remarkable level of understanding of coronavirus & the COVID-19 disease as a multidimensional construct, covering the SARS-CoV-2 side, & medical, social, & psychological consequences on people’s lives

Children’s conceptions of coronavirus. Fotini Bonoti, Vasilia Christidou, Penelope Papadopoulou. Public Understanding of Science, October 9, 2021. https://doi.org/10.1177/09636625211049643

Abstract: The present study aimed to examine children’s conceptions of coronavirus as denoted in their verbal descriptions and drawings and whether these vary as a function of children’s age and the mode of expression. Data were collected in Greece during spring 2020 and 344 children aged 4 to 10 years were first asked to verbally describe coronavirus and then to produce a drawing of it. Content analysis of data revealed the following main themes: (a) Coronavirus, (b) Medical, (c) Psychological, and (d) Social. Results showed that children from an early age present a remarkable level of understanding of coronavirus and the COVID-19 disease as a multidimensional construct, which can be designated not only through characteristics of the Sars-Cov-2 but also through its medical, social, and psychological consequences on people’s lives. Moreover, children were found to emphasize different aspects of this construct depending on their age and the mode of expression.

Keywords: children, conceptions, coronavirus, COVID-19, drawings


Twitter has a negative effect on conspiracy beliefs—as opposed to all other platforms under examination which are found to have a positive effect (Messenger, WhatsApp, YouTube, & Facebook)

Does the platform matter? Social media and COVID-19 conspiracy theory beliefs in 17 countries. Yannis Theocharis et al. New Media & Society, October 9, 2021. https://doi.org/10.1177/14614448211045666

Abstract: While the role of social media in the spread of conspiracy theories has received much attention, a key deficit in previous research is the lack of distinction between different types of platforms. This study places the role of social media affordances in facilitating the spread of conspiracy beliefs at the center of its enquiry. We examine the relationship between platform use and conspiracy theory beliefs related to the COVID-19 pandemic. Relying on the concept of technological affordances, we theorize that variation across key features make some platforms more fertile places for conspiracy beliefs than others. Using data from a crossnational dataset based on a two-wave online survey conducted in 17 countries before and after the onset of the COVID-19 pandemic, we show that Twitter has a negative effect on conspiracy beliefs—as opposed to all other platforms under examination which are found to have a positive effect.

Keywords: Affordances, conspiracy theories, COVID-19, misperceptions, social media

While the Internet has always served as a meeting place for fringe groups and conspiracy theorists, social media have added a new layer to this reality. Aided by the platforms’ interactive and networking features, as well as their capacity to deliver different kinds of content to very different audiences, social media have become hotspots for unsubstantiated information and the diffusion of misperceptions. Nevertheless, not all social media platforms should be painted with the same brush as different architectural features and affordances of social media platforms have consequences for how users encounter content and others with whom they can interact and build relationships (Bossetta, 2018).

The outbreak of the COVID-19 pandemic gave rise to many conspiracy theories, providing us with a unique opportunity to study conspiracy theory proliferation in platforms during the initial phase of the pandemic. We theorized that variation across different features of social media platforms might make some platforms more likely to accommodate conspiracy theory beliefs than others. Our results support the hypothesis that Twitter has a negative effect on conspiracy beliefs, while use of Facebook, YouTube, Messenger, and WhatsApp were found to have positive effects. For Facebook and its private messaging counterpart Messenger, it should, however, be noted that coefficients are only significant for the pooled models, when country effects were not weighted. Although this suggests that effects might not be uniform across countries, scrutinizing country differences is beyond the scope of this study and could make for a valuable endeavor for future research.

Our study makes several contributions. We show that not all social media platforms are the same when it comes to conspiracy theory beliefs about COVID-19. Our findings resonate with the core theoretical tenets of affordances theory, that there is a multifaceted relational structure between a technological tool and the user which might enable (in the case of Facebook, YouTube, and Messenger services) or constrain (in the case of Twitter) behavioral outcomes in a particular context (Evans et al., 2017: 36). This has implications for theory-building. Understanding how the spread of conspiracy theories differs across social media platforms is key to developing strategies to correct misperceptions, as well as to theorizing about how different features lead to different information diffusion dynamics. Our design does not allow us to tease out the specific effect of different affordances which would help understand why precisely we observe these effects, but the main finding lays the ground for future research zooming into individual affordances (network features, type of content, etc.) and studying the particular dynamics they give rise to. Specifically, a number of platform-specific features that we discussed earlier may have a link to how CTB proliferate. Future research focusing on the micro-mechanisms of the effects tied to specific affordances could consider a number of possibilities when studying, for example, Twitter’s distinct effect in comparison to other platforms. Twitter’s users combine higher than average education with a greater tendency for news-seeking and engagement into political discussions than any of the platforms in our study. This could imply that a larger number of users with potentially high-quality information sources were there to create content which, due to the asymmetrical structure of connections on the platform, can reach very far very fast through retweeting that cuts across different types of networks. In this fashion, it is possible that conspiratorial content—when it appeared—could be debunked fast or possibly “drown out” with better quality information or the sheer volume of those willing to quickly jump in and correct misperceptions. This is in contrast to platforms like Facebook or Messenger services, where the networks are not only more homogeneous, but countering opinions may be harder to emerge for different reasons. For example, precisely because of Facebook’s more family-and-friends oriented connections, users might think twice before attempting to correct conspiratorial content, as they are more likely to have to face the cost of jeopardizing social relationships. Indeed, the topic of how to talk to friends and family sharing conspiracy theories on social media became the subject of many articles in reputable news sources once conspiracy theories started to emerge (Warzel, 2020). But while this might be very relevant to Facebook users, it is not a barrier to Twitter users who could have happened upon a conspiratorial content and decided to interject (or hijack) a discussion with their own evidence. The contrast between Twitter also holds for YouTube where, due to the platform’s architecture, upon watching a video users have to move to the comments to encounter any debate about the content, thus possibly having less exposure to corrective information other than those flagged by the platform (when that happenes).

Different approaches to platform governance might have also played a significant role, meaning that some platforms need more oversight than others. Twitter quickly put in place measures such as deprioritizing content that could pose risks to people’s health along with labels and warning messages to content that contained COVID-19 misinformation. Facebook, which eventually instituted similar measures, continues to face criticism for being too slow to act on groups profiting from COVID-19 conspiracy theories (Jackson et al., 2021) and it is possible that related content or groups were able to gain substantial audiences before they were blocked (Marchal and Au, 2020). Finally, as none of the two messenger services has the type of warnings or content removal practices implemented on Twitter or Facebook, letting private conversations (often among large groups) be unmoderated could have increased the likelihood for conspiratorial content to proliferate on these. Zooming into the specific affordance-related mechanisms would help identify which parts of the conspiracy theory diffusion chain platforms need to work harder on to make their products safer, especially when it comes to public health. While the COVID-19 pandemic should serve as an important case study on how platforms react when scientific consensus in relation to content previously labeled as misinformation shifts, our findings add to the mounting evidence enticing social media platforms to self-reflect on the information quality in their environments and its potential broader effects on citizen attitudes and beliefs that are essential for public choices.

While our study has focused on conspiratorial beliefs about COVID-19, there is a little theoretical reason to believe that the effects we uncover would not apply to other types of conspiracy theories. This reasoning implies that our study has applications to a far larger problem than COVID-19-specific conspiracy theories. Future research should re-examine the connection of platform type and conspiracy theory beliefs using other conspiracy theories.

Our study does not come without limitations. The most important one is selection bias, which our data and design do not allow us to settle definitively. We have provided a strong theoretical rationale that platforms’ diverse features might be responsible for the way in which each platform is connected to conspiracy theory beliefs. It is, however, also possible that users’ particular characteristics or motivations may shape their decision to use this or the other platform precisely because it can offer the type of environment that fits their individual or community needs best. In recognition of this limitation, we employed propensity score matching which enabled us to find users with comparable characteristics to non-users across platforms, thus providing an additional test that our assumptions about the role of platforms are robust. This is an important test as, compared to regression-based techniques, this technique at least does not rely on out of data range extrapolations. Nevertheless, the ideal design for disentangling the causal order in this puzzle is, ultimately, a randomized experimental design. Random assignment into platforms could come with significant challenges, however, given the social media saturated environment of our times, and the difficulties of compliance with being active on a singular platform (Theocharis and Lowe, 2016). Ultimately, one would have to trade external validity for internal validity, which is why no single study design can stand alone.

Despite these shortcomings, our study provides important evidence that future studies based on other designs can build upon to address an issue of increasing importance given the role of platforms in people’s media and socialization diets.

Rolf Degen summarizing... Strangers to ourselves: People carelessly neglect habits and latch on to internal states when explaining their own or others' behavior

Mazar, Asaf, and Wendy Wood. 2021. “Illusory Feelings, Elusive Habits: Explanations of Behavior Overlook Habits.” PsyArXiv. October 9. doi:10.31234/osf.io/ug86s

Abstract: Habits underlie much of human behavior. However, people may prefer agentic explanations that overlook habits in favor of inner states such as mood. We tested this misattribution hypothesis in an online experiment of helping behavior as well as an ecological momentary assessment study of college students’ everyday coffee drinking. Both studies revealed a substantial gap between attributed and actual influences on behavior: Habit strength outperformed or matched inner states in predicting behavior, whereas participants’ attributions for their behavior emphasized inner states. Participants continued to overlook habits even when incentivized for accuracy, as well as when making attributions for other people’s behavior. We discuss how this attribution pattern could adversely influence self-regulation.


Saturday, October 9, 2021

The size of scientific fields may impede the rise of new ideas: Fundamental progress may be stymied if quantitative growth of scientific endeavors—in number of scientists, institutes, & papers—is not balanced by focusing attention on novel ideas

Slowed canonical progress in large fields of science. Johan S. G. Chu and James A. Evans. Proceedings of the National Academy of Sciences, October 12, 2021 118 (41) e2021636118; https://doi.org/10.1073/pnas.2021636118

Significance: The size of scientific fields may impede the rise of new ideas. Examining 1.8 billion citations among 90 million papers across 241 subjects, we find a deluge of papers does not lead to turnover of central ideas in a field, but rather to ossification of canon. Scholars in fields where many papers are published annually face difficulty getting published, read, and cited unless their work references already widely cited articles. New papers containing potentially important contributions cannot garner field-wide attention through gradual processes of diffusion. These findings suggest fundamental progress may be stymied if quantitative growth of scientific endeavors—in number of scientists, institutes, and papers—is not balanced by structures fostering disruptive scholarship and focusing attention on novel ideas.

Abstract: In many academic fields, the number of papers published each year has increased significantly over time. Policy measures aim to increase the quantity of scientists, research funding, and scientific output, which is measured by the number of papers produced. These quantitative metrics determine the career trajectories of scholars and evaluations of academic departments, institutions, and nations. Whether and how these increases in the numbers of scientists and papers translate into advances in knowledge is unclear, however. Here, we first lay out a theoretical argument for why too many papers published each year in a field can lead to stagnation rather than advance. The deluge of new papers may deprive reviewers and readers the cognitive slack required to fully recognize and understand novel ideas. Competition among many new ideas may prevent the gradual accumulation of focused attention on a promising new idea. Then, we show data supporting the predictions of this theory. When the number of papers published per year in a scientific field grows large, citations flow disproportionately to already well-cited papers; the list of most-cited papers ossifies; new papers are unlikely to ever become highly cited, and when they do, it is not through a gradual, cumulative process of attention gathering; and newly published papers become unlikely to disrupt existing work. These findings suggest that the progress of large scientific fields may be slowed, trapped in existing canon. Policy measures shifting how scientific work is produced, disseminated, consumed, and rewarded may be called for to push fields into new, more fertile areas of study.

Keywords: scientific progressdurable dominanceentrepreneurial futilityscience policyscience of science

Discussion

These findings suggest troubling implications for the current direction of science. If too many papers are published in short order, new ideas cannot be carefully considered against old, and processes of cumulative advantage cannot work to select valuable innovations. The more-is-better, quantity metric-driven nature of today’s scientific enterprise may ironically retard fundamental progress in the largest scientific fields. Proliferation of journals and the blurring of journal hierarchies due to online article-level access can exacerbate this problem.

Reducing quantity may be impossible. Proscribing the number of annual publications, shuttering journals, closing research institutions, and reducing the number of scientists are hard-to-swallow policy prescriptions. Even if a scientist wholeheartedly agreed with the implications of our study, curtailing their output would be impractical given the damage to their career prospects and those of their colleagues and students, for example. Limiting article quantity without altering other incentives risks deterring the publication of novel, important new ideas in favor of low-risk, canon-centric work.

Still, some changes in how scholarship is conducted, disseminated, consumed, and rewarded may help accelerate fundamental progress in large fields of science. A clearer hierarchy of journals with the most-prestigious, highly attended outlets devoting pages to less canonically rooted work could foster disruptive scholarship and focus attention on novel ideas. Reward and promotion systems, especially at the most prestigious institutions, that eschew quantity measures and value fewer, deeper, more novel contributions could reduce the deluge of papers competing for a field’s attention while inspiring less canon-centric, more innovative work. A widely adopted measure of novelty vis a vis the canon could provide a helpful guide for evaluations of papers, grant applications, and scholars. Revamped graduate training could push future researchers to better appreciate the uncomfortable novelty of ideas less rooted in established canon. These measures, while not easy to implement across large fields, may help push scholarship off the local attractor of existing canon and toward more novel frontiers.

The current study is at the level of fields and large subfields, and one could argue that progress now occurs at lower subdisciplinary levels. To examine lower levels at scale requires more precise methods for classifying papers—perhaps using temporal citation network community detection—than are currently available. But note that the fields and subfields identified in the Web of Science correspond closely to real-world self-classifications of journals and departments. Established scholars transmit their cognitive view of the world to their students via field-centric reading lists, syllabi, and course sequences, and field boundaries are enforced through career-shaping patterns of promotion and reward.

It may be that progress still occurs, even though the most-cited articles remain constant. While the most-cited article in molecular biology (22) was published in 1976 and has been the most-cited article every year since 1982, one would be hard pressed to say that the field has been stagnant, for example. But recent evidence (23) suggests that much more research effort and money are now required to produce similar scientific gains—productivity is declining precipitously. Could we be missing fertile new paradigms because we are locked into overworked areas of study?

Children do not judge animals (chicken, cows, & pigs) to be appropriate food sources; 41pct of children claimed that bacon came from a plant

Children are unsuspecting meat eaters: An opportunity to address climate change. Erin R. Hahn, Meghan Gillogly, Bailey E. Bradford. Journal of Environmental Psychology, October 9 2021, 101705. https://doi.org/10.1016/j.jenvp.2021.101705

Highlights

• Children are not reliably accurate in identifying the origins of common foods.

• Forty-one percent of children claimed that bacon came from a plant.

• Children do not judge animals to be appropriate food sources.

• Most 6- and 7-year-olds classified chicken, cows, and pigs as not OK to eat.

• Children's food concepts may help to normalize environmentally-responsible diets.

Abstract: Eating a plant-based diet is one of the most effective ways people can reduce their carbon footprint. However, global consumption of meat and other animal products is increasing. Studying children's beliefs about food may shed light on the relationship between eating behaviors and climate change. Here, we examined children's knowledge of the plant and animal origins of foods, as well as children's judgments of what can be eaten, using 2 dichotomous sorting tasks. The sample consisted of 4- to 7-year-old children from the United States. We found pervasive errors in their basic food knowledge. Foods derived from animals—especially, but not exclusively meats—were among those that children understood the least well. We suggest that the results may reveal a fundamental misunderstanding in children's knowledge of animal based foods, and we discuss reasons why the origins of meat may represent a particularly challenging concept for children to grasp. We end by considering the role that children may play as agents of environmental protection.

Keywords: Sustainable dietsAnimalsMeat eatingMeat paradoxClimate changeChildren


Language offers a unique window into psychology; natural-language processing & comparative linguistics are contributing to how we understand topics as diverse as emotion, creativity, & religion

From Text to Thought: How Analyzing Language Can Advance Psychological Science. Joshua Conrad Jackson et al. Perspectives on Psychological Science, October 4, 2021. https://doi.org/10.1177/17456916211004899

Abstract: Humans have been using language for millennia but have only just begun to scratch the surface of what natural language can reveal about the mind. Here we propose that language offers a unique window into psychology. After briefly summarizing the legacy of language analyses in psychological science, we show how methodological advances have made these analyses more feasible and insightful than ever before. In particular, we describe how two forms of language analysis—natural-language processing and comparative linguistics—are contributing to how we understand topics as diverse as emotion, creativity, and religion and overcoming obstacles related to statistical power and culturally diverse samples. We summarize resources for learning both of these methods and highlight the best way to combine language analysis with more traditional psychological paradigms. Applying language analysis to large-scale and cross-cultural datasets promises to provide major breakthroughs in psychological science.

Keywords: natural-language processing, comparative linguistics, historical linguistics, psycholinguistics, cultural evolution, emotion, religion, creativity

Psychological science still has work to do before researchers can master NLP and comparative linguistic methods. We dedicate the rest of this article to illustrating how that might happen. First, we present Figure 4, which is a visual flowchart illustrating how the language-analysis methods discussed in this article can be employed to address psychological questions. We then summarize three case studies that demonstrate how NLP and comparative linguistics can yield new insights and increase the scale and diversity of study into three psychological constructs that have been notoriously difficult to study—emotion, religion, and creativity. In these sections, we highlight research that has used language analysis to address new questions or solve long-standing debates or that has used language-analysis methods to increase the scale or cultural diversity of research in these fields. This work illustrates the utility of language analysis for asking enduring psychological questions and foreshadows the potential of these tools to address psychological constructs across social, cultural, cognitive, clinical, and developmental psychology.


                        figure

Fig. 4. A flowchart of different language-analysis methods and the kinds of questions they are best suited to answer. Orange boxes represent methods from comparative linguistics, and gray boxes represent methods from NLP. Black boxes approximate the questions that may guide researchers toward these methods. Concepts are defined here as the meaning associated with words. This is meant as a general guide for researchers interested in language analysis, and there is some overlap in classifications. For example, word embeddings can show how language conveys moods and attitudes, and colexification can sometimes uncover evolutionary dynamics.

Emotion

Questions and debates about the nature of human emotion have existed since the earliest days of psychological science (Darwin, 1872/1998James, 1884Spencer, 1894Wundt, 1897) and are relevant to psychological questions pertinent to social, clinical, and developmental psychology. Language-analysis methods have already increased the scope of this long-standing field and generated original methods of addressing old debates.

One of the most enduring debates about emotions concern whether emotions are universal, inborn categories that possess little variation around the world or are socially learned categories that vary in their experience and conceptualization across cultures (Cowen & Keltner, 2020Ekman & Friesen, 1971Izard, 2013Plutchik, 1991Lindquist et al., 2012Mesquita et al., 2016Russell, 2003). We recently addressed this question by means of a comparative-linguistics approach using colexifications (Jackson, Watts, et al., 2019). This analysis allowed us to increase the scale and generalizability over previous field studies of cross-cultural differences in emotion that had relied on smaller sample sizes and two-culture comparisons (Bryant & Barrett, 2008Ekman & Friesen, 1971Gendron et al., 201420152020).

In our study, we computationally aggregated thousands of word-lists and translation dictionaries into a large database named “CLICS” (https://clics.clld.org/), and we used this database to examine colexification patterns of 24 emotion concepts across 2,474 languages. We constructed networks of colexification in which nodes represented concepts (e.g., “anger”) and edges represented colexifications (instances in which people had named two concepts with the same word), and then compared emotion colexification networks across language families. In contrast to Youn and colleagues (2016), who found universal colexification patterns involving concepts such as “sun” and “sky,” we found wide cultural variation in the colexification of emotion concepts such as “love” and “fear.” In fact, clusters of emotion colexification varied more than three times as much as the clustering patterns of colors—our set of control concepts—across language families (see Fig. 5). For example, “anxiety” was perceived as similar to “fear” among Tai-Kadai languages, but was more related to “grief” in Austroasiatic languages, suggesting that speakers of these language may conceptualize anxiety differently.


                        figure

Fig. 5. The colexification structure of emotion concepts for all languages (top left) and for five individual language families in Jackson and colleagues (2019) analysis of emotion. Nodes are emotion concepts, and links between concepts represent the likelihood that these concepts will be colexified in a language. Color indicates semantic community, which refers to clusters of emotions that are similar in meaning. From Jackson, J. C., Watts, J., Henry, T. R., List, J. M., Forkel, R., Mucha, P. J., Greenhill, S., Gray, R. D., & Lindquist, K. A. (2019). Emotion semantics show both cultural variation and universal structure. Science366(6472), 1517–1522. https://doi.org/10.1126/science.aaw8160. Reprinted with permission from AAAS.

The variability in emotion meaning that we observed was associated with the geographic proximity of language families, suggesting that the meaning of emotion may be transmitted through historical patterns of contact (e.g., warfare, trade) and common ancestry. We also found that emotions universally clustered together on the basis of their hedonic valence (whether or not they were pleasant to experience) and to a lesser extent, by their physiological activation (whether or not they involved high levels of physiological arousal), suggesting valence and physiological activation might be biologically based factors that provide “minimal” universality to the meaning of emotion. In sum, this study used an unprecedented sample of cultures to yield new insights into the structure and cultural variation of human emotion.

A different set of language-analysis studies involving NLP are improving how psychologists measure emotion and track it over time and across social networks. For example, in a study of unprecedented historical scale, Morin and Acerbi (2017) used sentiment analysis to examine English fiction from 1800 to 2000 to assess whether the expression of emotion had changed systematically over time. They found a decrease in positive (but not negative) emotions conveyed in language over history in three separate corpora of text. This change could not be explained by changing writer demographics (e.g., age and gender), vocabulary size, or genre (fiction vs. nonfiction), raising the possibility that something about emotion or its expression has itself changed over time.

Other studies have also used language analysis to track faster emotional dynamics, such as measuring the emotional qualities of social-media posts (Roberts et al., 2012Yu & Wang, 2015) and testing whether the emotions of one person are likely to rapidly spread via language throughout that person’s social network. Such studies have shown experimentally that emotional sentiment conveyed by language on social-media websites (e.g., Facebook) is more likely to make individuals who view that language express similar emotions (Kramer et al., 2014). Correlational studies find that social-media information with high emotional content is more likely to be shared than information with low emotional content (Brady et al., 2017). These studies show how affect can spread across many social-media users in a short period of time.

Religion

The science of religion has a rich legacy equal to that of the psychology of emotion; many psychological studies have addressed questions about the social value and historical development of religion. Language analysis has recently begun answering both kinds of questions with a scope and ecological validity that was not possible with traditional methods.

NLP analyses have shed light on the positive and negative ways that religion affects happiness and intergroup relations. Some social theorists view religion as a primarily positive force because it reinforces social connections and promotes well-being (Brooks, 2007). On the other hand, “New Atheism” suggests that religion has a more negative effect on psychology by narrowing people’s worldviews and homogenizing the beliefs of religious adherents (Dawkins & Ward, 2006Hitchens, 2008). Evidence for this debate has been mixed because of methodological challenges. For example, religious people frequently report more well-being than atheists in large national surveys, but they also show more social-desirability bias (Gervais & Norenzayan, 2012), which makes their self-reports less reliable.

NLP analyses are able to overcome these social-desirability limitations and have begun to show ecologically valid evidence that religion is linked to well-being. For example, Ritter et al. (2014) conducted a sentiment analysis of 16,000 users on Twitter and found that Christians expressed more positive emotion, less negative emotion, and more social connectedness than nonreligious users. Wallace et al. (2019) conducted a creative analysis of obituaries, finding that people whose obituaries mentioned religion had lived significantly longer than people whose obituaries did not mention religion, even controlling for demographic information.

Other NLP research has called the New Atheist proposition of religious worldview homogeneity into question. For example, Watts and colleagues (2020) analyzed the explanations that Christian and nonreligious participants generated to explain a wide range of supernatural and natural phenomena and estimated the overlap of these explanations as a measure of worldview homogeneity. If religion does indeed homogenize adherents’ worldviews, one would expect that religious people’s explanations would share greater overlap than nonreligious people’s explanations. Watts and colleagues (2020) used a text analysis approach known as Jaccard distances, which was able to estimate the similarity between participants’ explanations of the world using overlapping key words, and test whether religious people offered more homogeneous explanations than did nonreligious people. Using this algorithm, the researchers found that religious people’s explanations of supernatural phenomena were more homogeneous than nonreligious people’s explanations, but their explanations of natural phenomena (e.g., the prevalence of parasites) were more diverse than were nonreligious explanations, probably because they drew on supernatural as well as scientific concepts when explaining the natural world.

Comparative linguistics has mostly contributed to questions about how religion has developed over time across cultures. Many of these analyses have focused on the “supernatural monitoring hypothesis”: that watchful and punitive gods contributed to the evolution of social groups by increasing in-group prosociality and fostering large-scale cooperation (Johnson, 2016Norenzayan et al., 2016). This idea is nearly a century old, arguably dating back to Durkheim (1912/2008), but most tests of the hypothesis have been correlational, and there is an ongoing debate about whether societies with large-scale cooperation tend to adopt moralistic religions or societies that adopt moralistic religions tend to be more cooperative (Whitehouse et al., 2019).

Researchers using comparative-linguistics methods recently addressed these debates by focusing on the development of religion in the Pacific Islands, where linguistic analyses have mapped out cultural phylogenies that can then be repurposed for cross-cultural research (R. D. Gray et al., 2009). Using these phylogenetic trees and implementing a method known as Pagel’s discrete (Pagel, 1999), Watts and colleagues (2015) inferred the probability that ancestor cultures had high levels of political complexity (indicating large-scale cooperation), the probability that they believed in supernatural punishment, and the probability that they worshiped moralizing high gods. Their results showed partial support for both sides of the debate about religion and cooperation. Broad supernatural punishment (e.g., punishment for violating taboos) tended to precede and facilitate political complexity. However, belief in watchful and punitive high gods (e.g., the Christian God) tended to occur only when societies were already politically complex.

Phylogenetic analyses have also shed light on the darker side of religious evolution, such as ritualized human sacrifice practices, which were common across the ancient world. According to the social-control hypothesis, ritual human sacrifice was used as a tool to help build and maintain social inequalities by demonstrating the power of leaders and instilling fear among subjugates. Yet evidence in support of this theory was based largely on individual case studies showing that higher classes often orchestrated ritual sacrifices (Carrasco, 1999Turner & Turner, 1999). Watts and colleagues (2016) tested this prediction by examining patterns of ritual human sacrifice and social inequality across 93 Pacific societies that had been mapped onto an established language phylogeny (R. D. Gray et al., 2009). They found evidence that ritual human sacrifice often preceded, facilitated, and helped to sustain social inequalities, supporting the social-control hypothesis.

Creativity

Compared with the psychology of emotion and religion, that of creativity has a shorter history in psychology. Most psychologists agree that creativity contributes to personal feelings of self-fulfillment and societal innovation (Pratt & Jeffcutt, 2009Wright & Walton, 2003), but the field is still exploring the best ways to measure creativity as a psychological construct. More than a dozen creativity-measurement paradigms exist in psychology. One such measure asks participants to name multiple uses for common household items such as article clips and bricks (Guilford, 1950), whereas others require participants to think of creative marketing schemes (Lucas & Nordgren, 2015) or draw an alien from another planet (Ward, 1994). In each paradigm, responses are qualitatively scored on creativity by trained research assistants. Although these tasks are themselves quite creative, the coding process can be onerous, and it can take months to obtain creativity ratings for a small behavioral study. Because these measures require custom tasks and laboratory settings, they are also rarely suitable for analyzing real-world creative behavior.

Language analysis has only recently been applied to study creativity, but NLP techniques are already advancing the measurement of creativity with paradigms that can be applied to both individuals in a small study as well as millions of people around the world. One such paradigm is “forward flow” (K. Gray et al., 2019). Forward flow asks people to free associate concepts, much like classic psychoanalysis methods. But rather than qualitatively deconstructing these free associations, forward flow uses word embeddings to quantitatively analyze the extent that present thoughts diverge from past thoughts. For example, because “dog” and “cat” are frequently used together in large corpora, “dog” → “cat” would not represent as much divergence as “dog” → “fortress,” which are less frequently used together. Forward flow correlates with higher creativity scores on validated behavioral tasks such as the multiple uses task, and creative professionals such as actors, performance majors, and entrepreneurs score highly on forward flow (K. Gray et al., 2019). Forward flow in celebrities’ social-media posts can even predict their creative achievement (K. Gray et al., 2019). Forward flow may represent a rich and low-cost measure that could help capture creativity across people and societies.

Other NLP analyses have captured creativity in terms of divergences from normative language (e.g., Kuznetsova et al., 2013). Much like an unorthodox-looking alien, unorthodox patterns of language can signal creativity. However, it can be difficult to distinguish nonnormative and creative language (e.g., “metal to the pedal,” which is a reformulation of “pedal to the metal”) from nonnormative and nonsensical language (e.g., “the metal pedal to”). Berger and Packard (2018) developed a potential solution to this problem in a study of the music industry and used this method to test how creativity related to a product’s success. Their approach first used topic modeling to develop words that frequently appeared in different genres of music. For instance, words about bodies and movement were often featured in dance songs, whereas words about women and cars were often featured in country music songs. The study next quantified each song from the sample on its typicality according to how much it used language typical of its genre. Analyzing these trends found that songs that broke from tradition and featured atypical language performed better than songs featuring more typical language, offering some evidence that people prefer creative cultural products.

Recent language-analysis studies have already made a considerable impact on the study of creativity and show the potential of NLP for capturing and quantifying variability in creativity across people and products. Although no comparative-linguistics research has examined creativity, this subfield also has great potential for examining whether creativity varies in its structure across cultures and how creativity has evolved across history. Some historical analyses suggest that creativity has been highest during periods of societal looseness—periods with less rigid social norms and more openness (Jackson, Gelfand, et al., 2019). But this research was done on American culture, and it is not clear whether these findings would generalize around the world.

Sexual differences in human cranial morphology: Is one sex more variable or one region more dimorphic?

Sexual differences in human cranial morphology: Is one sex more variable or one region more dimorphic? Marco Milella, Daniel Franklin, Maria Giovanna Belcastro, Andrea Cardini. The Anatomical Record, March 26 2021. https://doi.org/10.1002/ar.24626

Abstract: The quantification of cranial sexual dimorphism (CSD) among modern humans is relevant in evolutionary studies of morphological variation and in a forensic context. Despite the abundance of quantitative studies of CSD, few have specifically examined intra-sex variability. Here we quantify CSD in a geographically homogeneous sample of adult crania, which includes Italian individuals from the 19th and 20th centuries. Cranial morphology is described with 92 3D landmarks analyzed using Procrustean geometric morphometrics (PGMM). Size and shape variables are used to compare morphological variance between sexes in the whole cranium and four individual regions. The same variables, plus Procrustes form, are used to quantify average sex differences and explore classification accuracy. Our results indicate that: (a) as predicted by Wainer's rule, males present overall more variance in size and shape, albeit this is statistically significant only for total cranial size; (b) differences between sexes are dominated by size and to a lesser extent by Procrustes form; (c) shape only accounts for a minor proportion of variance; (d) the cranial base shows almost no dimorphism for shape; and (e) facial Procrustes form is the most accurate predictor of skeletal sex. Overall, this study suggests developmental factors underlying differences in CSD among cranial regions; stresses the need for population-specific models that describe craniofacial variation as the basis for models that facilitate the estimation of sex in unidentified skeletal remains; and provides one of the first confirmations of “Wainer's rule” in relation to sexual dimorphism in mammals specific to the human cranium.