Wednesday, June 24, 2020

Poker is a game of skill and chance involving economic decision-making under uncertainty, with a strong potential as a model system for studying high-stakes, high-risk expert performance

Poker as a Domain of Expertise. Jussi Palomäki, Michael Laakasuo, Benjamin Ultan Cowley, and Otto Lappi. Journal of Expertise, Vol. 3(2). Jun 2020.

Abstract: Poker is a game of skill and chance involving economic decision-making under uncertainty. It is also a complex but well-defined real-world environment with a clear rule-structure. As such, poker has strong potential as a model system for studying high-stakes, high-risk expert performance. Poker has been increasingly used as a tool to study decision-making and learning, as well as emotion self-regulation. In this review, we discuss how these studies have begun to inform us about the interaction between emotions and technical skill, and how expertise develops and depends on these two factors. Expertise in poker critically requires both mastery of the technical aspects of the game, and proficiency in emotion regulation; poker thus offers a good environment for studying these skills in controlled experimental settings of high external validity. We conclude by suggesting ideas for future research on expertise, with new insights provided by poker.

Keywords: Economic decisions, probabilistic decision-making, risk, expertise, poker

Respondents rated photographs of patients with facial paralysis significantly lower in likeability, trustworthiness, attractiveness, and femininity or masculinity

Association of Facial Paralysis With Perceptions of Personality and Physical Traits. Keon M. Parsa. JAMA Netw Open. 2020;3(6):e205495, June 24 2020, doi:10.1001/jamanetworkopen.2020.5495

Key Points
Question  How is facial paralysis associated with the perception of attractiveness, femininity or masculinity, and personality, and do patient-reported outcome measures correlate with how patients are perceived by others?

Findings  In this cross-sectional study including 20 patients with facial paralysis and 122 survey respondents, respondents rated photographs of patients with facial paralysis significantly lower in likeability, trustworthiness, attractiveness, and femininity or masculinity compared with the digitally edited images of patients without facial paralysis. Higher social function and total Facial Clinimetric Evaluation scores were associated with increased trustworthiness and attractiveness scores.

Meaning  These results broaden understanding of how facial paralysis is associated with societal perceptions of persona.

Importance  Facial paralysis has a significant effect on affect display, with the most notable deficit being patients’ the inability to smile in the same way as those without paralysis. These impairments may result in undesirable judgements of personal qualities, thus leading to a significant social penalty in those who have the condition.

Objective  To quantify the association of facial paralysis with the way smiling patients are perceived by others with respect to personality traits, attractiveness, and femininity or masculinity and to evaluate the potential association of facial palsy–related patient-reported outcome measures with how patients are perceived by others.

Design, Setting, and Participants  This retrospective cross-sectional study used 20 images of smiling patients with facial paralysis evaluated between January 1, 2014, and December 31, 2016. Using photograph editing software, the photographs were edited to create a simulated nonparalysis smiling facial appearance. A total of 40 photographs were split into 4 groups of 10 photographs, each with 5 altered and 5 unaltered photographs. The surveys were designed such that altered and unaltered photographs of the same patient were not placed in the same survey to avoid recall bias. Anonymous raters used a 7-point Likert scale to rate their perception of each patient’s personality traits (ie, aggressiveness, likeability, and trustworthiness), attractiveness, and femininity or masculinity based on photographs in their assigned survey. Raters were blinded to study intent. Scores from the Facial Clinimetric Evaluation questionnaire were included to assess self-perception. Data were analyzed from November 11, 2019, to February 20, 2020.

Main Outcomes and Measures  Ratings of personality traits, attractiveness, and femininity or masculinity. Social function domain scores and overall scores were analyzed from the Facial Clinimetric Evaluation questionnaire.

Results  This study included photographs of 20 patients with facial paralysis (mean [range] age, 54 [28-69] years; 15 [75%] women). A total of 122 respondents completed the survey (71 [61%] women). Most respondents were between the ages of 25 and 34 years (79 participants [65%]). Overall, smiling photos of patients with facial paralysis were perceived as significantly less likeable (difference, −0.29; 95% CI, −0.43 to −0.14), trustworthy (difference, −0.25; 95% CI, −0.39 to −0.11), attractive (difference, −0.47; 95% CI, −0.62 to −0.32), and feminine or masculine (difference, −0.21; 95% CI, −0.38 to −0.03) compared with their simulated preparalysis photographs. When analyzed by sex, smiling women with facial paralysis experienced lower ratings for likeability (difference, −0.34; 95% CI, −0.53 to −0.16), trustworthiness (difference, −0.24; 95% CI, −0.43 to −0.06), attractiveness (difference, −0.74; 95% CI, −0.94 to −0.55), and femininity (difference, −0.35; 95% CI, −0.58 to −0.13). However, smiling men with facial paralysis only received significantly lower ratings for likeability (difference, −0.24; 95% CI, −0.47 to −0.01) and trustworthiness (difference, −0.30; 95% CI, −0.53 to −0.07). As patients’ self-reported social function and total Facial Clinimetric Evaluation scores increased, there was an increase in perceived trustworthiness (rs[480] = 0.11; P = .02) and attractiveness (rs[478] = 0.10; P = .04) scores by raters.

Conclusions and Relevance  In this study, photographs of patients with facial paralysis received lower ratings for several personality and physical traits compared with digitally edited images with no facial paralysis. These findings suggest a social penalty associated with facial paralysis.

The Duchenne smile is classically described as the anatomical marker of the genuine smile. The smile is distinctive, with the mouth turning up from the activation of the zygomatic major muscle, the cheeks lifting, and the appearance of wrinkles around the eyes (also known as crow’s feet) associated with simultaneous contraction of the orbicularis oculi. The absence of the Duchenne smile not only influences how people evaluate smiles but also how they are judged by others.29,30
The findings of this cross-sectional study suggest that the inability to effectively smile is associated with negative perceptions in likeability, trustworthiness, attractiveness, and femininity or masculinity for patients with facial paralysis. Paralysis affecting the mouth is among the most notable of facial asymmetries, such that palsies of the zygomatic and marginal branches of the facial nerve are considered to have a significantly greater need for correction.11,12 Interestingly, reanimation surgery of the lip significantly decreases the degree of attention to the mouth and can help decrease negative perceptions of patients with facial paralysis.31
A universal finding for our patient population was lower perceived trustworthiness for the photographs of patients with facial paralysis vs their digitally altered counterparts. Research in the psychological and social sciences corroborate these findings, such that a happy facial expression makes a person appear more trustworthy.31,32 Furthermore, having a facial appearance that conveys a positive emotional state enhances trust.33-35 These findings highlight the social significance of the asymmetric smile and the importance of further progress in the development of techniques to assist in mitigating the effects of facial paralysis.
It is interesting to find that men and women with facial paralysis did not experience the same social penalty with respect to their facial paralysis. The relative decrease in attractiveness and femininity perceived in women with facial paralysis likely reflects the different social expectations by sex in our society. This is consistent with the results reported in a 2019 study36 that suggest that the appearance of a smile is not as integral to the perception of masculinity as it is to femininity.
Lastly, there was a correlation between the way patients with facial paralysis perceived themselves and how they were perceived by others. Specifically, as self-perception of social function and overall facial function improved, there was an increase in perceived trustworthiness and attractiveness by others. This is similar to the results reported by Lyford-Pike et al37 that suggest that higher FaCE scores correspond with decreased perception of disfigurement by patients.
It is important to note that this study included patients with facial paralysis presenting with a range of facial impairment. Not all patients with facial paralysis experienced a significant decrease in the perception of their personality traits, femininity or masculinity, and attractiveness. More research is needed to better understand the different variables that can optimize outcomes at the individual patient level.

There are several limitations to this study. This study was performed using static smiling images, but other studies have found that observers judged the severity of paralyzed faces to be more noticeable when viewing dynamic expressions.38 In addition, as this study included only patients willing to have their photos viewed by others, there may have been a selection bias rendering the study patient group to be less reflective of the true gamut of patients with facial paralysis.39

Twitter: While partisan opinion leaders are certainly polarized, centrist/non-political voices are much more likely to produce the most visible information; & there is little evidence of echo-chambers in consumption

Mukerjee, Subhayan, Kokil Jaidka, and Yphtach Lelkes. 2020. “The Ideological Landscape of Twitter: Comparing the Production Versus Consumption of Information on the Platform.” OSF Preprints. June 23. doi:10.31219/

Abstract: There are mounting concerns that the information environment on Twitter is fragmented along ideological lines, with users ensconced into echo chambers with limited exposure to cross-cutting views. Previous studies have typically relied on small populations of political elites or opinion leaders to appraise this level of fragmentation. This study makes two main advancements over the existing body of literature. First, it identifies the need to make the distinction between information production and consumption. Second, it proposes weighted estimates of ideology, based on active use, to better assess the extent of polarization on the platform. Our analyses find little evidence that Twitter, at least in the United States, is polarized based on how information is produced by opinion leaders. While partisan opinion leaders are certainly polarized, centrist or non-political voices are much more likely to produce the most visible information on the platform. Analysis of co-exposure networks of how ordinary Americans follow these opinion leaders similarly reveals little evidence of echo-chambers in consumption. However, while the extent of ideological selective consumption is low, there does exist a small but dedicated audience for conservative opinion leaders on the platform.

Check also Echo Chambers Exist! (But They're Full of Opposing Views). Jonathan Bright, Nahema Marchal, Bharath Ganesh, Stevan Rudinac. arXiv Jan 30 2020. arXiv:2001.11461.

And: The rise in the political polarization in recent decades is not accounted for by the dramatic rise in internet use; claims that partisans inhabit wildly segregated echo chambers/filter bubbles are largely overstated:
Deri, Sebastian. 2019. “Internet Use and Political Polarization: A Review.” PsyArXiv. November 6.

And Testing popular news discourse on the “echo chamber” effect: Does political polarisation occur among those relying on social media as their primary politics news source? Nguyen, A. and Vu, H.T. First Monday, 24 (5), 6. Jun 4 2019.

Check also
Why Smart People Are Vulnerable to Putting Tribe Before Truth. Dan M Kahan. Scientific American, Dec 03 2018. 
Baum, J., Rabovsky, M., Rose, S. B., & Abdel Rahman, R. (2018). Clear judgments based on unclear evidence: Person evaluation is strongly influenced by untrustworthy gossip. Emotion, 
The key mechanism that generates scientific polarization involves treating evidence generated by other agents as uncertain when their beliefs are relatively different from one’s own: 
Scientific polarization. Cailin O’Connor, James Owen Weatherall. European Journal for Philosophy of Science. October 2018, Volume 8, Issue 3, pp 855–875. 
Polarized Mass or Polarized Few? Assessing the Parallel Rise of Survey Nonresponse and Measures of Polarization. Amnon Cavari and Guy Freedman. The Journal of Politics, 
Tappin, Ben M., and Ryan McKay. 2018. “Moral Polarization and Out-party Hate in the US Political Context.” PsyArXiv. November 2. 
Forecasting tournaments, epistemic humility and attitude depolarization. Barbara Mellers, PhilipTetlock, Hal R. Arkes. Cognition, 
Does residential sorting explain geographic polarization? Gregory J. Martin & Steven W. Webster. Political Science Research and Methods, 
Liberals and conservatives have mainly moved further apart on a wide variety of policy issues; the divergence is substantial quantitatively and in its plausible political impact: intra party moderation has become increasingly unlikely: 
Peltzman, Sam, Polarizing Currents within Purple America (August 20, 2018). SSRN: 
Does Having a Political Discussion Help or Hurt Intergroup Perceptions? Drawing Guidance From Social Identity Theory and the Contact Hypothesis. Robert M. Bond, 
Hillary C. Shulman, Michael Gilbert. Bond Vol 12 (2018),

All the interactions took the form of subjects rating stories offering ‘ammunition’ for their own side of the controversial issue as possessing greater intrinsic news importance:
Perceptions of newsworthiness are contaminated by a political usefulness bias. Harold Pashler, Gail Heriot. Royal Society Open Science, 
When do we care about political neutrality? The hypocritical nature of reaction to political bias. Omer Yair, Raanan Sulitzeanu-Kenan. PLOS, 
Democrats & Republicans were both more likely to believe news about the value-upholding behavior of their in-group or the value-undermining behavior of their out-group; Republicans were more likely to believe & want to share apolitical fake news:
Pereira, Andrea, and Jay Van Bavel. 2018. “Identity Concerns Drive Belief in Fake News.” PsyArXiv. September 11. 
In self-judgment, the "best option illusion" leads to Dunning-Kruger (failure to recognize our own incompetence). In social judgment, it leads to the Cassandra quandary (failure to identify when another person’s competence exceeds our own): The best option illusion in self and social assessment. David Dunning. Self and Identity, 
People are more inaccurate when forecasting their own future prospects than when forecasting others, in part the result of biased visual experience. People orient visual attention and resolve visual ambiguity in ways that support self-interests: "Visual experience in self and social judgment: How a biased majority claim a superior minority." Emily Balcetis & Stephanie A. Cardenas. Self and Identity, 
Can we change our biased minds? Michael Gross. Current Biology, Volume 27, Issue 20, 23 October 2017, Pages R1089–R1091. 
Summary: A simple test taken by millions of people reveals that virtually everybody has implicit biases that they are unaware of and that may clash with their explicit beliefs. From policing to scientific publishing, all activities that deal with people are at risk of making wrong decisions due to bias. Raising awareness is the first step towards improving the outcomes.
People believe that future others' preferences and beliefs will change to align with heir own:
The Belief in a Favorable Future. Todd Rogers, Don Moore and Michael Norton. Psychological Science, Volume 28, issue 9, page(s): 1290-1301, 
Kahan, Dan M. and Landrum, Asheley and Carpenter, Katie and Helft, Laura and Jamieson, Kathleen Hall, Science Curiosity and Political Information Processing (August 1, 2016). Advances in Political Psychology, Forthcoming; Yale Law & Economics Research Paper No. 561. Available at SSRN:
Abstract: This paper describes evidence suggesting that science curiosity counteracts politically biased information processing. This finding is in tension with two bodies of research. The first casts doubt on the existence of “curiosity” as a measurable disposition. The other suggests that individual differences in cognition related to science comprehension - of which science curiosity, if it exists, would presumably be one - do not mitigate politically biased information processing but instead aggravate it. The paper describes the scale-development strategy employed to overcome the problems associated with measuring science curiosity. It also reports data, observational and experimental, showing that science curiosity promotes open-minded engagement with information that is contrary to individuals’ political predispositions. We conclude by identifying a series of concrete research questions posed by these results.
Keywords: politically motivated reasoning, curiosity, science communication, risk perception
Facebook news and (de)polarization: reinforcing spirals in the 2016 US election. Michael A. Beam, Myiah J. Hutchens & Jay D. Hmielowski. Information, Communication & Society, 
The Partisan Brain: An Identity-Based Model of Political Belief. Jay J. Van Bavel, Andrea Pereira. Trends in Cognitive Sciences, 
The Parties in our Heads: Misperceptions About Party Composition and Their Consequences. Douglas J. Ahler, Gaurav Sood. Aug 2017, 
The echo chamber is overstated: the moderating effect of political interest and diverse media. Elizabeth Dubois & Grant Blank. Information, Communication & Society,
Processing political misinformation: comprehending the Trump phenomenon. Briony Swire, Adam J. Berinsky, Stephan Lewandowsky, Ullrich K. H. Ecker. Royal Society Open Science, published on-line March 01 2017. DOI: 10.1098/rsos.160802,
Competing cues: Older adults rely on knowledge in the face of fluency. By Brashier, Nadia M.; Umanath, Sharda; Cabeza, Roberto; Marsh, Elizabeth J. Psychology and Aging, Vol 32(4), Jun 2017, 331-337.
Stanley, M. L., Dougherty, A. M., Yang, B. W., Henne, P., & De Brigard, F. (2017). Reasons Probably Won’t Change Your Mind: The Role of Reasons in Revising Moral Decisions. Journal of Experimental Psychology: General. 
Science Denial Across the Political Divide — Liberals and Conservatives Are Similarly Motivated to Deny Attitude-Inconsistent Science. Anthony N. Washburn, Linda J. Skitka. Social Psychological and Personality Science, 10.1177/1948550617731500. 
Biased Policy Professionals. Sheheryar Banuri, Stefan Dercon, and Varun Gauri. World Bank Policy Research Working Paper 8113. 
Dispelling the Myth: Training in Education or Neuroscience Decreases but Does Not Eliminate Beliefs in Neuromyths. Kelly Macdonald et al. Frontiers in Psychology, Aug 10 2017. 
Individuals with greater science literacy and education have more polarized beliefs on controversial science topics. Caitlin Drummond and Baruch Fischhoff. Proceedings of the National Academy of Sciences, vol. 114 no. 36, pp 9587–9592, doi: 10.1073/pnas.1704882114, 
Expert ability can actually impair the accuracy of expert perception when judging others' performance: Adaptation and fallibility in experts' judgments of novice performers. By Larson, J. S., & Billeter, D. M. (2017). Journal of Experimental Psychology: Learning, Memory, and Cognition, 43(2), 271–288. 
Public Perceptions of Partisan Selective Exposure. Perryman, Mallory R. The University of Wisconsin - Madison, ProQuest Dissertations Publishing, 2017. 10607943. 
The Myth of Partisan Selective Exposure: A Portrait of the Online Political News Audience. Jacob L. Nelson, and James G. Webster. Social Media + Society, 
Echo Chamber? What Echo Chamber? Reviewing the Evidence. Axel Bruns. Future of Journalism 2017 Conference. 
Fake news and post-truth pronouncements in general and in early human development. Victor Grech. Early Human Development, 
Consumption of fake news is a consequence, not a cause of their readers’ voting preferences. Kahan, Dan M., Misinformation and Identity-Protective Cognition (October 2, 2017). Social Science Research Network,

Tuesday, June 23, 2020

Effectiveness of public apologies for sexual misconduct: More comprehensive & less defensive apologies received more favorable reactions; denials were viewed more favorably by men than women

Is moral redemption possible? The effectiveness of public apologies for sexual misconduct. Karina Schumann, Anna Dragotta. Journal of Experimental Social Psychology, Volume 90, September 2020, 104002.

• Examined reactions to apologies by public figures accused of sexual misconduct.
• More comprehensive and less defensive apologies received more favorable reactions.
• Denials were viewed more favorably by men than women.
• General attitudes toward apologies during #MeToo movement were slightly negative.
• Advances knowledge of public apologies, with comparisons to interpersonal apologies.

Abstract: Amidst an international movement against sexual violence in 2017, hundreds of high-profile men were accused of sexual misconduct, and people's news feeds were flooded with apologies issued by many of these men. In five studies (N = 1931), we examined people's reactions to these apologies, with a focus on how their perceived content (participants' evaluations of how comprehensive and non-defensive they were), the gender of the audience, and the severity of the allegations against the accused influenced their effectiveness relative to denials and “no comment” statements. Using both real statements issued during the #MeToo movement (Study 1) and experimentally controlled statements issued by fictitious (Studies 2–4) and real (Study 5) public figures, we found that what the accused men said in their statements indeed mattered. Apologies were more effective when they were more comprehensive and less defensive, and when they were offered in response to lower (versus higher) severity allegations. Consistent effects of gender also emerged, with women reacting less favorably to denials and “no comment” statements than men. On the whole, the findings provide intriguing evidence for parallels between public and interpersonal apologies, revealing that high-quality apologies hold some value in a context where doubts about the remorsefulness and morality of the apologizer abound. However, the benefits of even the highest quality apologies were modest, resembling those found in the literature on intergroup apologies. These findings thus suggest that the public may view apologies for sexual misconduct as an appropriate starting point—but certainly not endgame—for the accused men.

Keywords: ApologiesDenialsDefensivenessForgivenessSexual misconduct#MeToo

Expansive and Contractive Postures and Movement: A Systematic Review and Meta-Analysis of the Effect of Motor Displays on Affective and Behavioral Responses

Expansive and Contractive Postures and Movement: A Systematic Review and Meta-Analysis of the Effect of Motor Displays on Affective and Behavioral Responses. Emma Elkjær et al. Perspectives on Psychological Science, June 22, 2020.

Abstract: This review and meta-analysis explores the experimental effects of expansive and contractive motor displays on affective, hormonal, and behavioral responses. Experimental studies were located through systematic literature searches. Studies had to manipulate motor displays to either expansive or contractive displays and investigate the effect of the displays on affect, hormones, or overt behavior. Meta-analyses were conducted to determine the pooled, standardized mean differences between the effects of motor displays on affective, hormonal, and behavioral responses. From 5,819 unique records, 73 relevant studies were identified. Robust differences between expansive and contractive displays emerged for affective responses and overt behavioral responses across contexts, type of manipulation, and methods of measurement. The results suggest that the effects are driven by the absence of contractive motor displays (contractive vs. neutral displays: Hedges’s g = 0.45) rather than the presence of expansive displays (expansive vs. neutral displays: g = 0.06). The findings stand as a corrective to previous research, as they indicate that it is the absence of contractive displays rather than the presence of expansive displays that alters affective and behavioral responding. Future research should include neutral control groups, use different methods to assess hormonal change, and investigate these effects in the context of ideographic goals.

Keywords: methodology, quantitative, emotion, affect, expansive displays, contractive displays

Does the Punishment Fit the Crime (and Immune System)? A Potential Role for the Immune System in Regulating Punishment Sensitivity

Does the Punishment Fit the Crime (and Immune System)? A Potential Role for the Immune System in Regulating Punishment Sensitivity. Jeffrey Gassen, Summer Mengelkoch, Hannah K. Bradshaw and Sarah E. Hill. Front. Psychol., June 22 2020.

Abstract: Although the criminal justice system is designed around the idea that individuals are invariant in their responses to punishment, research indicates that individuals exhibit a tremendous amount of variability in their punishment sensitivity. This raises the question of why; what are the individual- and situation-level variables that impact a person’s sensitivity to punishment? In the current research, we synthesize theory and research on inflammation, learning, and evolutionary biology to examine the relationship between inflammatory activity and sensitivity to punishment. These theories combine to predict that inflammatory activity – which is metabolically costly and reflects a context in which the net payoff associated with future oriented behaviors is diminished – will decrease sensitivity to punishment, but not rewards. Consistent with this hypothesis, Study 1 found that in U.S. states with a higher infectious disease burden (a proxy for average levels of inflammatory activity) exhibit harsher sentencing in their criminal justice systems. Studies 2 and 3 experimentally manipulated variables known to impact bodily inflammatory activity and measured subsequent punishment and reward sensitivity using a probabilistic selection task. Results revealed that (a) increasing inflammation (i.e., completing the study in a dirty vs. clean room) diminished punishment sensitivity (Study 2), whereby (b) administering a non-steroidal anti-inflammatory drug, suppressing inflammatory activity, enhanced it. No such changes were found for reward sensitivity. Together, these results provide evidence of a link between the activities of the immune system and punishment sensitivity, which may have implications for criminal justice outcomes.

General Discussion

In the current research, we investigated the role that the activities of the immune system play in regulating punishment sensitivity. Based on insights from research in psychoneuroimmunology (Maier and Watkins, 1998Banks, 2005Dantzer and Kelley, 2007Lasselin et al., 2017Draper et al., 2018), and RSFT (Real and Caraco, 1986Lima and Dill, 1990Houston, 1991McNamara and Houston, 1992), we predicted that punishment sensitivity would decrease in contexts where inflammation is elevated and increase when inflammatory activity is diminished. This pattern was hypothesized to occur because in the context of heightened inflammation (a) an individual’s probability of survival is lower, lowering the payoffs one can expect from investing in future-oriented behaviors (e.g., Gassen et al., 2019abGassen and Hill, 2019), and (b) the immunometabolic constraints that occur in this context decrease one’s ability to inhibit dominant responses (see e.g., Lacourt et al., 2018Treadway et al., 2019).
Preliminary support for this hypothesis was found across three studies. Study 1 revealed that an environmental factor that promotes inflammatory activity (i.e., high infectious disease burden; e.g., Zhu et al., 1999Gattone et al., 2001Nazmi et al., 2010Thompson et al., 2014Ferrucci and Fabbri, 2018) was associated with the use of harsher punishments for criminal offenses. Although there may be numerous contributors that play a role in the association between these variables, it is consistent with the hypothesis that inflammation should predict reduced sensitivity to punishment, as harsher punishments are required to modify the behavior of individuals with lower punishment sensitivity (compared to those with higher punishment sensitivity; Jean-Richard-Dit-Bressel et al., 2018Marchant et al., 2018). In addition to providing initial support for the hypothesis that the activities of the immune system will predict meaningful differences in punishment sensitivity, these results suggest that this relationship could have implications for criminal justice outcomes.
Studies 2 and 3 found continued support for the hypothesized relationship between inflammatory activity and punishment sensitivity. Study 2 revealed that exposure to an environment that elicited increased inflammatory activity (measured via salivary IL-1β) led to diminished punishment sensitivity. The results of Study 3 found further support for this hypothesis, demonstrating that administering a manipulation designed to experimentally reduce inflammatory activity (via aspirin administration) led to an increase in punishment sensitivity. No difference in reward sensitivity was observed across these two studies. Taken together, these results suggest that the activities of the immune system – and inflammation in particular – play a role in regulating punishment sensitivity. Further, these results provide preliminary evidence that the relationship between punitive measures and infectious disease burden found in Study 1 may be driven by elevated inflammation leading to (a) decreased punishment sensitivity and (b) harsher punishments to compensate for reduced sensitivity to punishment.
Together, the results of the current research add to a growing body of work demonstrating an important role for the immune system in regulating processes involved in learning (see e.g., Depino et al., 2004Huang and Sheng, 2010Sartori et al., 2012). Further, the current work contributes to the body of research examining inflammatory activity and processes related to punishment sensitivity (see e.g., Pugh et al., 1998Patil et al., 2003Sparkman et al., 2005Kohman et al., 2007Harrison et al., 2016). The latter is particularly important given the inconsistent results found across previous studies using different methods. For example, some studies have found no association between states known to be associated with increased inflammatory activity and punishment sensitivity (Kunisato et al., 2012Berghorst et al., 2013). Others have found that heightened inflammatory activity increases punishment sensitivity (Harrison et al., 2016), with participants exhibiting more punishment sensitivity on a monetary task after an inflammatory response had been elicited via typhoid vaccination. One potential explanation for the inconsistencies between this previous work and the results of the current studies is that they reflect differences in the magnitude of the inflammatory response elicited by our manipulation (i.e., Study 2; dirty room) and theirs (i.e., typhoid vaccine). The typhoid vaccination used in Harrison et al. (2016) research resulted in an average 250% increase in plasma levels of interleukin-6, a proinflammatory cytokine. Our much subtler contextual manipulation of inflammation, on the other hand, only revealed an average 191% increase (with a rather large standard deviation) in IL-1β levels in saliva. As such, one possibility is that inflammation exerts a dose-dependent effect on punishment sensitivity, where small increases in inflammation may impair punishment sensitivity (as found in the current work), and larger increases in inflammation may enhance it (as found in Harrison et al., 2016). Moreover, differences in the timing of the punishment sensitivity task between our study and Harrison et al. (2016) may also help explain the disparate findings. Participants in the current research completed the PST shortly after entering the dirty room. In contrast, the behavioral task in Harrison et al. (2016) study was administered 2.5–3.5 h after vaccination. Thus, this could indicate that the effects of proinflammatory cytokines on reward and punishment sensitivity are time-dependent. Future research should examine these possibilities.
Much of the previous research studying the impact of inflammation on punishment sensitivity has been conducted using non-human animals. Consistent with the findings reported here, this animal research suggests that inflammatory challenges often reduce performance on tasks related to punishment sensitivity, such as avoiding aversive stimuli (e.g., foot shocks or predators) and contextual fear conditioning (Pugh et al., 1998Patil et al., 2003Sparkman et al., 2005Kohman et al., 2007Adelman et al., 2017). Moreover, during acute infection, which is associated with heightened inflammatory activity, house finches exhibit reduced behavioral avoidance of predators (Adelman et al., 2017).
Inherent in the current work are several limitations. For example, although Study 1 found that states with a greater infectious disease burden exhibited harsher punishments, it is possible that this association reflects processes other than reduced punishment sensitivity in the context of heightened inflammatory activity. For example, in addition to offenders, judges in high pathogen areas are also exposed to greater infectious disease risk than those in less pathogen dense areas. Thus, high infectious disease burden may influence psychological characteristics of judges (e.g., impulsivity) that render them more oriented toward harsher sentencing. Exploring these and other possibilities will be an important direction for future research.
The experimental studies also have important limitations. While Study 2 provided evidence that our manipulation of room cleanliness resulted in heightened inflammation and decreased punishment sensitivity, results did not provide evidence that levels of IL-1β mediated the relationship between room condition and punishment sensitivity. This could be due to a variety of factors. First, we only measured one proinflammatory cytokine, IL-1β. Given that a host of different proinflammatory proteins coordinates the inflammation response, it is possible that the relationship between room condition and punishment sensitivity is driven by a proinflammatory protein that we did not measure. Second, saliva samples were collected 30 min after exposure to room condition. It is possible that participants’ levels of inflammation were declining at this time and may not have been representative of their inflammatory levels during the task. As such, this detracts from our ability to make causal inferences about the role that inflammation plays in calibrating punishment sensitivity. However, it bears noting that past research examining the influence of experimental manipulations that elicit an inflammatory response on behavior often do not test or report whether inflammation serves as a mediator (e.g., Eisenberger et al., 2010Inagaki et al., 2012Harrison et al., 2016). It is important that future studies report these mediation analyses to provide evidence for or against claims of causal relationships between inflammation and behavioral outcomes.
Another potential limitation of Study 2 was our measurement of IL-1β in participants’ saliva samples, as opposed to peripheral blood samples (e.g., plasma or serum). Research into the strength of correlations between salivary and plasma/serum levels of cytokines across different contexts has yielded mixed results (e.g., Cruz-Almeida et al., 2017La Fratta et al., 2018Lee et al., 2018), and overall, there is a paucity of research on the topic. However, our primary objective for measuring levels of IL-1β was to provide a manipulation check on the prediction that exposure to the dirty room (compared to the clean room) would lead to a rise in inflammation. Recent research suggests that salivary measures of inflammation are well-suited for this purpose (e.g., Walsh et al., 2016Newton et al., 2017La Fratta et al., 2018Gassen et al., 2019a). The results of Study 2 should also be interpreted with caution given that there were unequal numbers of men and women between the two conditions. While sex was controlled for in the analyses and did not significantly interact with experimental condition to predict any outcome, this is still an important limitation to consider.
One unexpected difference in punishment sensitivity emerged between the control conditions in Studies 2 and 3. Specifically, punishment sensitivity was higher in the clean room condition of Study 2 than in the control condition of Study 3. While we cannot say for certain what accounted for these differences, there was heterogeneity in the methods and sample characteristics between the two studies that may have contributed to them. First, the testing rooms used for the control conditions in each study were not equivalent. Specifically, to increase perceptions of cleanliness in the clean room condition of Study 2, a number of steps were taken to increase the room’s cleanliness, including removing trash receptacles, wiping down all of the computers and keyboards with disinfectant wipes, and placing a large bottle of hand sanitizer near the sign-in sheet. Given that these extra steps were not taken in the second experiment (for which room cleanliness was not part of the manipulation), the room used for the control condition in Study 2 was even cleaner than that used for the control condition in Study 3. Accordingly, it is possible that differences in punishment sensitivity between the two control conditions (with higher sensitivity found in Study 2) can be attributed to greater cleanliness in the control condition for Study 2 compared to Study 3.
Further, in Study 2, before entering the experimental room, participants provided their initial saliva sample in a separate room. They were then transferred to the experimental room before completing the remainder of the study. This differs from the methodology utilized in Study 3, where the entire study was completed in a single room. Although it is unclear how these procedural differences may influence punishment sensitivity, they are worthy of note in this context. A final explanation for the differences in punishment sensitivity that emerged between these conditions could lie in differences between demographic characteristics of the samples. As is displayed in Tables 23, childhood and adult SES for the sample in the clean room condition for Study 2 were higher than for the control condition in Study 3 (d = 0.37–0.40). We are not aware of extant research finding SES-based differences in performance on the probabilistic selection task, specifically. However, more generally, research finds that those from a lower SES environment exhibit a higher risk for certain behavioral problems (e.g., impulsivity: Griskevicius et al., 2011), for which reduced punishment sensitivity has been identified as part of the underlying psychological architecture (e.g., Potts et al., 2006).

Humans navigate with stereo olfaction

Humans navigate with stereo olfaction. Yuli Wu et al. Proceedings of the National Academy of Sciences, June 22, 2020.

Significance: The human brain exploits subtle differences between the inputs to the paired eyes and ears to construct three-dimensional experiences and navigate the environment. Whether and how it does so for olfaction is unclear, although humans also have two separate nasal passages that simultaneously sample from nonoverlapping regions in space. Here, we demonstrate that a moderate internostril difference in odor intensity consistently biases recipients’ perceived direction of self-motion toward the higher-concentration side, despite that they cannot report which nostril smells a stronger odor. The findings indicate that humans have a stereo sense of smell that subconsciously guides navigation.

Abstract: Human navigation relies on inputs to our paired eyes and ears. Although we also have two nasal passages, there has been little empirical indication that internostril differences yield directionality in human olfaction without involving the trigeminal system. By using optic flow that captures the pattern of apparent motion of surface elements in a visual scene, we demonstrate through formal psychophysical testing that a moderate binaral concentration disparity of a nontrigeminal odorant consistently biases recipients’ perceived direction of self-motion toward the higher-concentration side, despite that they cannot verbalize which nostril smells a stronger odor. We further show that the effect depends on the internostril ratio of odor concentrations and not the numeric difference in concentration between the two nostrils. Taken together, our findings provide behavioral evidence that humans smell in stereo and subconsciously utilize stereo olfactory cues in spatial navigation.

Keywords: binaral disparityolfactory navigationheading perceptionoptic flow

Monday, June 22, 2020

Repetitive Transcranial Magnetic Stimulation as a Potential Tool to Reduce Sexual Arousal in cases of hypersexuality

Schecklmann M, Sakreida K, Oblinger B, et al. Repetitive Transcranial Magnetic Stimulation as a Potential Tool to Reduce Sexual Arousal: A Proof of Concept Study. J Sex Med 2020;XX:XXX–XXX.

Background: Hypersexuality and hyposexuality occur frequently, often in a variety of psychiatric disorders, and are difficult to treat. While there is meta-analytic evidence for the significant effect of non-invasive brain stimulation on drug and food craving, no study has investigated the potential of this technique to modulate sexual behavior.

Aim: Here, we tested the hypothesis that a single session of high-frequency repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) would reduce sexual arousal.

Methods: We employed a randomized, double-blind, sham-controlled crossover study design. 19 healthy male participants received high-frequency rTMS over the left DLPFC, high-frequency rTMS over the right DLPFC, and sham rTMS (each 10 Hz; 110% resting motor threshold; 60 trains with 50 pulses) in randomized and counterbalanced order with a 1-week interval between stimulation sessions to avoid carryover effects. Participants were exposed to neutral and sexual cues before and after each intervention and rated their sexual arousal after each block of cue presentation.

Main Outcome Measure: Efficacy of the respective intervention was operationalized by the change of subjective sexual arousal according to a rating scale.

Results: rTMS of the right DLPFC significantly reduced subjective sexual arousal (t18 = 2.282, P = .035). In contrast, neither sham rTMS nor rTMS of the left DLPFC affected sexual arousal (P > .389). Greater rTMS-induced reduction of subjective sexual arousal was observed in participants with higher trait-based dyadic sexual desire within the last 12 months (r = −0.417, P = .038).

Clinical Implication: Non-invasive brain stimulation might hold potential for influencing hypersexual behavior.

Strength & Limitation: This was a randomized, double-blind, sham-controlled crossover study with subjective but no physiological measures of sexual arousal.

Conclusion: The results indicate that 1 session of high-frequency rTMS (10 Hz) of the right DLPFC could significantly reduce subjective sexual arousal induced by visual stimuli in healthy subjects. On this basis, future studies with larger sample sizes and more stimulation sessions are needed to explore the therapeutic potential of rTMS in hypersexual behavior.

Key Words: Dorsolateral Prefrontal CortexHypersexualNeuromodulationSexual ArousalRepetitive Transcranial Magnetic Stimulation

Pathological lying exists in a small percentage of people, for whom it causes significant distress, impaired functioning, and danger; it has a prevalence of 8%–13%

Pathological Lying: Theoretical and Empirical Support for a Diagnostic Entity. Drew A. Curtis and Christian L. Hart. Psychiatric Research & Clinical Practice, Jun 22 2020.

.  Pathological lying exists in a small percentage of people, for whom it causes significant distress, impaired functioning, and danger.
.  Pathological lying, distinct from normative lying and prolific lying, has a prevalence of 8%–13%.
.  Evidence supports establishing pathological as a diagnostic entity.

Objective: Pathological lying, originally called “pseudologia phantastica,” has an established history within clinical practice and literature, although it has not been recognized as a psychological disorder within major nosological systems. With the movement in psychological sciences toward theory-driven, empirically supported diagnoses, the current study sought to empirically test whether pathological lying aligned with nosological definitions and could be defined as a diagnostic entity.

Methods: A total of 807 people were recruited (January to October of 2019) from various mental health forums, social media, and a university. Of those recruited, 623 completed the study. Participants responded to a lie frequency prompt, questionnaires about lying behavior, the Lying in Everyday Situations Scale, the Distress Questionnaire-5, and demographic questions.

Results: Of the participants, 13% indicated that they self-identified or that others had identified them as pathological liars (telling numerous lies each day for longer than 6 months). People who identified as pathological liars reported greater distress, impaired functioning, and more danger than people not considered pathological liars. Pathological lying seemed to be compulsive, with lies growing from an initial lie, and done for no apparent reason.

Conclusions: The evidence supports establishment of pathological lying as a distinct diagnostic entity. A definition of pathological lying, etiological considerations, and recommendations for future research and practice are presented.

Negativity bias, positivity bias, and valence asymmetries: Explaining the differential processing of positive and negative information

Negativity bias, positivity bias, and valence asymmetries: Explaining the differential processing of positive and negative information. Christian Unkelbach, Hans Alves, Alex Koch. Advances in Experimental Social Psychology, June 2020.

Abstract: Distinguishing between “good” and “bad” is a fundamental task for all organisms. However, people seem to process positive and negative information differentially, described in the literature as instances of negativity bias, positivity bias, or valence asymmetries. We provide an overview of these processing differences and their explanations. First, we review negativity advantages: People attend more to negative information, recall it more, and weigh it more heavily, relative to positive information. Second, we review positivity advantages: People process positive information faster, have broader associations from it, and show stronger congruency effects, relative to negative information. We then discuss existing explanations for these differential effects in terms of phylogenetic pressures, correlates of valence, diagnosticity, mobilization-minimization, and top-down vs. bottom-up processing. Finally, we suggest the differential similarity of positive and negative information as a unifying explanation. We delineate why positive information should be more alike relative to negative information, and how differential similarity translates to the observed processing differences. Then we show how the similarity explanation leads to novel predictions and how it solves old puzzles. Similarity thereby provides an explanatory construct for both positivity and negativity advantages, allowing precise quantitative predictions for valence asymmetries beyond the mere classification of “good” and “bad.”

Keywords: Negativity biasPositivity biasValence asymmetriesInformation ecologySocial cognition

In the XIX century most laws enacted in the USA were special bills that granted favors to specific individuals/groups/localities; their ban gave rise to the modern regulatory state & interest-group politics

Economic Crisis, General Laws, and the Mid-Nineteenth-Century Transformation of American Political Economy. Naomi R. Lamoreaux, John Joseph Wallis. NBER Working Paper No. 27400, June 2020.

Abstract: Before the middle of the nineteenth century most laws enacted in the United States were special bills that granted favors to specific individuals, groups, or localities. This fundamentally inegalitarian system provided political elites with important tools that they could use to reward supporters, and as a result, they were only willing to modify it under very special circumstances. In the early 1840s, however, a major fiscal crisis forced a number of states to default on their bonded debt, unleashing a political earthquake that swept this system away. Starting with Indiana in 1851, states revised their constitutions to ban the most common types of special legislation and, at the same time, mandate that all laws be general in their application. These provisions dramatically changed the way government and the economy worked and interacted, giving rise to the modern regulatory state, interest-group politics, and a more dynamic form of capitalism.

Gender Discrepancies in Perceptions of the Bodies of Female Fashion Models: Men do not find the ultra-thin body ideal for women as attractive as women believe men do

Gender Discrepancies in Perceptions of the Bodies of Female Fashion Models. Sarah N. Johnson & Renee Engeln. Sex Roles, Jun 22 2020.

Abstract: For over 30 years, researchers and journalists have made the claim that men do not prefer the level of thinness typically embodied by female fashion models, along with the secondary claim that women overestimate the extent to which men find these ultra-thin bodies attractive. The current studies examined men’s and women’s perceptions of the bodies of fashion models shown in media images, as well as how each gender believed the other would perceive the models’ bodies. In Study 1, 548 U.S. college students rated the body size and attractiveness of 13 images of models from women’s fashion magazines. Respondents also indicated how they thought the other gender would rate the models on these dimensions. In Study 2, 707 men and women recruited from Amazon’s Mechanical Turk completed the same rating task. Overall, both men and women overestimated how ideal the other gender would find the models’ bodies (both in terms of thinness and attractiveness). This misperception was strongest when women estimated how men would react to the models’ bodies. Results were consistent with previous studies suggesting that men do not find the ultra-thin body ideal for women as attractive as women believe men do. These gender-based misconceptions may contribute to the negative effects of viewing ultra-thin media images on women’s body image.

Sunday, June 21, 2020

Growing collectivism: irrigation, group conformity and technological divergence

Growing collectivism: irrigation, group conformity and technological divergence. Johannes C. Buggle. Journal of Economic Growth volume 25, pages147–193, Jun 4 2020.

Abstract: This paper examines whether collaboration within groups in pre-industrial agriculture favored the emergence of collectivist rather than individualist cultures. I document that societies whose ancestors jointly practiced irrigation agriculture historically have stronger collectivist norms today. This finding holds across countries, sub-national districts within countries, and migrants, and is robust to instrumenting the historical adoption of irrigation by its geographic suitability. In addition, I find evidence for a culturally-embodied effect of irrigation agriculture on economic behavior. Descendants of irrigation societies innovate less today, and are more likely to work in routine-intensive occupations, even when they live outside their ancestral homelands. Together, my results suggest that historical differences in the need to act collectively have contributed to the global divergence of culture and technology.

Meal-time photographers were more likely to eat in response to external cues (e.g. the sight of palatable food) than to internal cues of hunger; no influence in the amount or enjoyment of food eaten

When the camera eats first: Exploring how meal-time cell phone photography affects eating behaviours. Joceline Y.Y. Yong, Eddie M.W. Tong, Jean C.J. Liu. Appetite, June 21 2020, 104787.

Abstract: Advances in cell phone technology have the potential to disrupt eating patterns. In this research, we focused on the camera function of a cell phone, characterizing: (i) the extent to which this function is used during meals; (ii) whether meal-time photographers show signs of pathological eating; and (iii) whether the act of taking food photographs alters the amount and enjoyment of food eaten. In the first study, we used the experience sampling method to track one week of meals from 137 young adults. Although we observed a low base rate of meal-time photography (5.44% of the 1140 meals captured), phone users who engaged in this practice had higher external eating scores than those who did not. That is, these meal-time photographers were more likely to eat in response to external cues (e.g. the sight of palatable food) than to internal cues of hunger. However, when participants were randomly assigned to take either food or non-food photographs within a lab setting (Study 2), we found no evidence that the type of photography influenced either the amount or enjoyment of food eaten. Taken together, our findings suggest a limited role for cell phone photography in an obesogenic environment.

Keywords: Screen timeCell phoneFood ritualsExternal eatingFood intakeExperience sampling

Factors Influencing Premarital Sexual Attitude among Adolescents in East Coast Malaysia

Factors Influencing Premarital Sexual Attitude among Adolescents in East Coast Malaysia. Misron, Siti Nor Fadhlina; Husain, Maruzairi. International Medical Journal . Jun2020, Vol. 27 Issue 3, p259-262.

Background: Adolescence is a transitional period whereby a person attempts to try something new and risky including premarital sexual behaviour. Their attitudes are influenced by multiple factors that change over time.
Objective: This study highlights current factors influencing premarital sexual attitude among adolescents in East Coast Malaysia.
Methods: This cross-sectional study was conducted among 150 adolescents in the East Coast of Malaysia. Self-rated questionnaire on Premarital Sexual Attitude Among Secondary School Students was used to determine the prevalence of sexual attitude.
Results: All participants were 18 years old and have completed secondary school. The majority were Malay and Muslim. The prevalence of poor sexual knowledge and permissive premarital sexual attitude stood at 40.7% and 42.7% respectively. All the variables concerned with high-risk sexual behaviour namely reading pornography, watching pornography, sexual fantasy, and masturbation have higher prevalence compared to others with the percentages being 40.0%, 46.7%, 32.0%, and 34.7% respectively. Protective factors against permissive attitude identified were being male, non-Malay, perceived as being loved by parents, and having parents who know their child's friends.
Conclusion: Permissive attitude among adolescents towards premarital sex is associated with risky sexual behaviours. Thus, it is very important to explore the changing factors to identify the recent target groups so that future intervention can be done by emphasizing more on these identified factors.

Anger expressions when shown by men tend to be more consistently attributed to the event that caused the expression; for women tend to be more strongly attributed to her (angry) character

Anger is a Positive Emotion – At Least for Those who Show it. Ursula Hess. ISRE Logo Emotion Researcher, May 2020.

Abstract: In this article, I am discussing the notion that anger can be considered a positive emotion for those who feel it and for society at large. Anger has the ability to motivate people to act against injustice and norm violations in general and it provides the actor with (physical) strength, but also with an optimistic tendency to take risks. However, as a caveat it should be noted that even though anger does this for both men and women, women who show anger are liked less.

One in five (22%) US Americans reported recently having “experienced anger a lot yesterday” (Gallup World Poll, 2019). That surely is a bad thing? Webster’s Thesaurus’ list of synonyms for anger includes animosity, antagonism, embitterment, enmity, hostility, malevolence, and virulence, all of which refer to strife and destruction (Merriam Webster, 2019).Berkowitz and Harmon-Jones (2004)define anger as: “a syndrome of relatively specific feelings, cognitions, and physiological reactions linked associatively with an urge to injure some target” (p. 108). It is in this sense that Gallup adds anger to its Negative Experience Index, together with such states as worry and stress. Interestingly, the question is related to feeling angry – that is, Gallup considers feeling angry a negative experience. But is it? In Gallup’s view feeling anger is negative because it signals that there are things out there that cause this feeling – negative things in fact. But is reacting with anger to a negative event necessarily a bad thing? And for whom?

Anger did not have a significant effect on depth of information processing for any of the emotional comparison groups; these complex results indicate that anger is an exceedingly nuanced emotion

A discrete emotion with discrete effects: effects of anger on depth of information processing. Meaghan McKasy. Cognitive Processing, Jun 20 2020.

Abstract: There is relative paucity in the comprehensive study of anger and information processing. Emotions can impact the depth of information processing and anger is a powerful high-certainty emotion. Yet, the magnitude of the effects of anger on the depth of information processing has not been summarized. This scholarship performs a meta-analytic synthesis to report the effect of anger on the depth of information processing as compared to one of the four contrast groups: neutral control, sadness, happiness, and fear. A systematic search identified 26 articles with a total of 39 unique studies and 113 effect sizes. The evaluation revealed that anger did not have a significant effect on depth of information processing for any of the emotional comparison groups. Furthermore, the presence of publication bias was only found for one analysis. These complex results indicate that anger is an exceedingly nuanced emotion. The implications of the study and future scholarship are discussed.

Saturday, June 20, 2020

Why are consistently-handed individuals more authoritarian? The role of need for cognitive closure

Why are consistently-handed individuals more authoritarian? The role of need for cognitive closure. Keith B. Lyle  & Michael C. Grillo. Laterality: Asymmetries of Brain, Behaviour, and Cognition. Volume 25, 2020 - Issue 4, Jun 4 2020.

ABSTRACT: Recent studies indicate that individuals with consistent hand preference are more authoritarian than individuals whose preference is relatively inconsistent. We explored the role of epistemic needs in the handedness-authoritarianism relationship. Based on findings that consistent individuals are less cognitively flexible than inconsistent individuals, we hypothesized that consistent-handers would report greater need for definite knowledge. To measure this, we administered the revised Need for Cognitive Closure scale to a sample of undergraduates (N = 235), along with measures of handedness consistency and authoritarian submission. Consistent individuals scored significantly higher on authoritarian submission and need for closure. Need for closure fully mediated the relationship between consistency and submission. Consistent individuals also expressed greater prejudice against authoritarian out-groups such as immigrants and liberals. This effect was partially mediated by authoritarian submission. We theorize that consistent-handers’ cognitive inflexibility leads them to covet definite knowledge. These individuals turn to authoritarianism because it promises to stifle dissent and protect existing (conventional) knowledge.

KEYWORDS: Handedness consistency, need for closure, authoritarianism, prejudice

The current west-east asymmetry of Antarctic surface climate change is undoubtedly of natural origin because no external factors (e.g., orbital or anthropogenic factors) contribute to the asymmetric mode

The internal origin of the west-east asymmetry of Antarctic climate change. Sang-Yoon Jun et al. Science Advances Jun 12 2020, Vol. 6, no. 24, eaaz1490. DOI: 10.1126/sciadv.aaz1490

Abstract: Recent Antarctic surface climate change has been characterized by greater warming trends in West Antarctica than in East Antarctica. Although this asymmetric feature is well recognized, its origin remains poorly understood. Here, by analyzing observation data and multimodel results, we show that a west-east asymmetric internal mode amplified in austral winter originates from the harmony of the atmosphere-ocean coupled feedback off West Antarctica and the Antarctic terrain. The warmer ocean temperature over the West Antarctic sector has positive feedback, with an anomalous upper-tropospheric anticyclonic circulation response centered over West Antarctica, in which the strength of the feedback is controlled by the Antarctic topographic layout and the annual cycle. The current west-east asymmetry of Antarctic surface climate change is undoubtedly of natural origin because no external factors (e.g., orbital or anthropogenic factors) contribute to the asymmetric mode.


The model experiments conducted by CESM1 were not enough to fully confirm the roles of different regional SST forcings. Thus, we try to reinforce our logic weighted to the local atmosphere-ocean coupled feedback off West Antarctica through inference by comparing the regressed SST patterns among HadISST1, 38 CMIP5 models (CMIP5 MMM), and CESM1 onto their respective normalized EOF2 PC time series (fig. S9). In the tropics, there are large discrepancies between the observation and models, i.e., tropical central Pacific cooling in HadISST1, overall tropical and midlatitude cooling in CMIP5 MMM, and El Niño in CESM1. The large discrepancy in the tropical pattern associated with the Antarctic asymmetric mode implies that the dominant contribution of the tropical SST forcing to the upper-tropospheric anticyclonic circulation over West Antarctica cannot be generalized. By contrast, the consistent pattern of the warmer ABS SST is seen over the Southern Hemisphere high-latitude ocean. On the basis of this fact, it is natural to determine that the regional SST anomalies around Antarctica are the essential component for the asymmetry. The consistency between the observation and models over the high-latitude ocean enables us to think it reasonable to argue the harmony of the atmosphere-ocean coupled feedback off West Antarctica and the Antarctic terrain to generate the Antarctic west-east asymmetric natural variability.
In the asymmetric mode of Antarctic SATs, multidecadal variability is found in the long paleoclimate datasets of PAGES Antarctica2k, LOVECLIM, and TraCE-21K. This suggests that the enhanced asymmetric trend between West and East Antarctica during recent decades could be a manifestation of multidecadal variability. The linkage between the climatic conditions over the ABS and the Antarctic surface asymmetry at different time scales seems to determine time scales with either interannual or multidecadal variabilities. First, because the atmospheric Rossby wave bridge makes the connection between the tropics and west Antarctic surface climate (71116), strong interannual variability in the tropics, such as ENSO, might contribute to variability in the Antarctic asymmetric mode. On the other hand, different seasonalities in the interaction between the atmosphere and ocean could alter the interannual variability because the interaction between sea level pressure and surface temperature over the Bellingshausen Sea has strong seasonality. Their correlation coefficients shift from negative during austral summer (r = −0.17 for February) to positive during austral winter (r = 0.53 for August). This seasonality contributes to the wintertime development of the asymmetric mode, including the increase in surface temperature and the high-pressure system over this region, but disturbs the persistence of asymmetry in the following warm season. Second, the long-term variability in the ocean over the West Antarctic coastal region seems to play a role in producing multidecadal periodicity. There have been some reports on long-term variability of the ocean in this region via ocean circulation changes (202126). Possible roles of the ocean through the ASL have been suggested (20), but the relationship between the ocean and ASL is not immediately clear.
The climatic modes in this study suggest an important implication for future climate change in East Antarctica under global warming. The two future climate change experiments suggest that the explained variance in the first mode is much higher in the 21st century, while the second mode diminishes. The characteristics of the two modes strongly suggest that if global warming continues, a substantial temperature increase over East Antarctica may occur in addition to ongoing West Antarctic warming. The asymmetric mode will persist at its own pace in the future, even under global warming, but its role may not be as great as it is now. The intensified global warming over all of Antarctica in the future can induce massive melting of the ice shelves, even in East Antarctica. This explains why we have to keep an eye on Antarctica as global warming continues, despite the recent mitigation of warming in the eastern part of the region, due to the asymmetric nature of climate change.