Affective polarization (steady growth of the mutual dislike between Republicans and Democrats): Elites in the US have polarized faster than those in eight other OECD countries of study

Cross-Country Trends in Affective Polarization. Levi Boxell, Matthew Gentzkow, Jesse M. Shapiro. NBER Working Paper No. 26669, January 2020. https://www.nber.org/papers/w26669

Abstract: We measure trends in affective polarization in nine OECD countries over the past four decades. The US experienced the largest increase in polarization over this period. Three countries experienced a smaller increase in polarization. Five countries experienced a decrease in polarization. These findings are most consistent with explanations of polarization based on changes (e.g., changing party composition, growing racial divisions, the emergence of partisan cable news) that are more distinctive to the US, and less consistent with explanations based on changes (e.g., the emergence of the internet, rising economic inequality) that are more universal.

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4.2 Evaluation of Potential Explanations

Figure 3 plots average trends in each explanatory variable separately for the groups of countries

with rising or falling affective polarization. Appendix Figure 6 plots the individual series for each of the explanatory variables that we consider.

Internet and broadband penetration increased in all countries over the sample period, yet affective polarization did not. This is inconsistent with implication (i). Moreover, internet penetration appears to have risen faster in countries with falling polarization. This is inconsistent with implication (ii). The fact that in many countries polarization rose faster in the post-2000 period than the pre-2000 period is consistent with a role for digital media, but digital media cannot account for the rapid growth in affective polarization in the US and Canada during the 1990s. (See also Boxell et al. 2017.)

Income inequality, as measured by the Gini coefficient, increased in all sample countries except Switzerland, for which we have limited data. This is inconsistent with implication (i). Moreover, the data do not exhibit evidence of implication (ii).

Openness to trade, as measured by the trade share of GDP, likewise increased fairly broadly over the sample period, with no clear evidence of a faster increase in those countries with increasing affective polarization.

All countries experienced an increase in the foreign-born share of the population over the period for which we have data, and differences in the rate of growth do not appear to align with differences in the trends in affective polarization.

In our view, the data do not support the hypothesis that these factors played an important role in the rise in affective polarization in the US in the sense of equations (1) and (2).

Other explanations are more consistent with our data. The period we study saw important changes in the composition of the political parties in the US. Among both political elites and voters, party identification became increasingly aligned with both political ideology and social identities such as race and religion (McCarty et al. 2008; Abramowitz and Saunders 2008; Levendusky 2009; Fiorina 2016, 2017; Mason and Wronski 2018; Valentino and Zhirkov 2017).6 Many scholars have identified such “party sorting” among voters as a key potential cause of affective polarization, with sorting leading those from opposite parties to differ more on average in both ideology and identity (Iyengar et al. 2019; Mason 2016, 2018; Fiorina and Abrams 2008; Webster and Abramowitz 2017). The underlying drivers of party sorting are not fully understood, and sorting could be a consequence as well as a cause of affective polarization (Lelkes 2018). However, many drivers emphasized in the literature, such as the realignment of the parties in the South following the civil rights era, are distinctive to the US and originate at least in part in the strategic choices of political elites rather than the shifting views of voters themselves (Fiorina and Abrams 2008, p. 581; Levendusky 2009, 2010; Lupu 2015; Banda and Cluverius 2018).7

Consistent with the view that changing party composition is distinctive to the US, Rehm and Reilly (2010) find that, according to expert ratings of party positions, elites in the US have polarized faster than those in the eight other OECD countries we consider. Some of these countries (e.g., Canada) have experienced smaller increases in polarization among political elites, and some (e.g., Australia, Norway, Sweden, Germany, and the UK) have experienced declines in elite polarization. Consistent with the hypothesized mechanism, Canada has also experienced growing partisan differences in issue positions among voters (Kevins and Soroka 2018), whereas Britain and Germany have experienced overall declines (Adams et al. 2012a; Munzert and Bauer 2013). Fiorina’s (2017, Chapter 8) review of this and related evidence likewise concludes that the US has experienced faster growth in elite polarization and party differences in issue positions among voters than countries in Western Europe.

Increased party sorting by race has also been highlighted as a potentially important driver of affective polarization (see, e.g., Valentino and Zhirkov 2017; Abramowitz 2018; Mason and Wronski 2018; Westwood and Peterson 2019). Such sorting may in turn be driven by the growth in the non white share of the population. With the caveat that it is difficult to define and compare racial composition across countries and time periods (see Appendix A.6), it is noteworthy that the increase in the non-white share has been twice as large in countries with rising affective polarization as in those with falling affective polarization (see Figure 3).

The rise of 24-hour partisan cable news provides another potential explanation. Partisan cable networks emerged during the period we study and arguably played a much larger role in the US than elsewhere, though this may be in part a consequence rather than a cause of growing affective polarization. The timing of the introduction of Fox News appears roughly consistent with the acceleration of the growth in affective polarization during the 1990s, as well as with the observation that older demographic groups both consume more partisan cable news and have polarized more quickly than younger demographic groups in the US (Boxell et al. 2017; Martin and Yurukoglu 2017). Interestingly, the five countries with a negative linear slope for affective polarization all devote more public funds per capita to public service broadcast media than three of the countries with a positive slope (Benson and Powers 2011, Table 1; see also Benson et al. 2017).

Check also Merkley, Eric, and Dominik Stecula. 2020. “Party Cues in the News: Democratic Elites, Republican Backlash and the Dynamics of Climate Skepticism.”  British Journal of Political Science. Preprint January 25. https://www.bipartisanalliance.com/2020/01/supporters-of-republican-party-have.html

Metal music fans exhibit moral reasoning styles dependent on their metal sub-genre identification; the moral reasoning styles explain partially lyrical preferences that weren’t already explained by personality

Morality in everything, chapter 23958:

The role of moral reasoning & personality in explaining lyrical preferences. Kyle J. Messick, Blanca E. Aranda. PLoS One, January 24, 2020. https://doi.org/10.1371/journal.pone.0228057

Abstract: Previous research has supported that personality traits can act to a precursor to media preferences. Due to the ongoing association between morality and media preferences in public and political discourse (e.g., blaming immoral behaviours on media preferences), this research sought to expand the knowledge about factors that contribute to media preferences by investigating if moral reasoning styles explain some of the variance that was not already explained by personality traits. A specific form of media preferences were chosen – lyrical preferences in metal music – as claims between metal lyrical themes and behaviour have been ongoing since the 1980s, despite a lack of empirical evidence to support these claims. A lyrical preferences scale was developed, and utilizing this scale, it was found that different types of metal fans exhibit different moral reasoning styles dependent on their metal sub-genre identification. Further, it was found that moral reasoning styles explain a portion of the variance in lyrical preferences that weren’t already explained by personality traits. In particular, lyrical preferences were often thematically consistent with moral reasoning content and personality traits, such as that individuals that preferred lyrics about celebrating metal culture and unity had higher levels of the group loyalty moral reasoning domain alongside being higher in extraversion. The implications of moral reasoning styles and personality traits as being precursors to media preferences are discussed.

Discussion

This study examined the association between lyrical preferences, moral reasoning domains, and personality traits. We first developed a lyrical preferences scale that allowed for comparisons between members of the metal music community. We then identified differences about moral reasoning based on the type of metal preference (e.g., black metal fans had the lowest scores on the sanctity/degradation moral foundation), and further analyses revealed a rather nuanced understanding about how lyrical preferences are related to moral foundations.

Correlations showed that enjoying lyrics about depression, hardships, love, and emotional turmoil (i.e. human experience) are related to having higher scores on the care/harm and fairness moral domains, which suggests that those people who prefer these lyrics might find the struggles of others related to their own hardships, and might be more empathetic to those struggles. Individuals who showed a preference for vulgar lyrics, such as misogyny, violence, and Satanism in their lyrical content, have significantly lower scores on the sanctity/degradation moral domain compared to other metal fans. One possible explanation is that these metal music fans have a different understanding of sanctity (e.g., thinking of the body as a temple), which is materialised in how these music fans with vulgar/immoral lyrical preferences have higher levels of extreme and unusual piercings and body modifications than metal fans with other lyrical preferences (something we recorded in this study, but was not a focus of the analysis). It is also possible that those who prefer more disgusting lyrics are approaching the idea of disgust in a fundamentally different way than most other music and metal music fans. Adding further cause for concern, the sanctity/degradation subscale has recently been questioned for how inconsistently it applies to people who are not religious [64], which is primarily the case for metal fans in the current sample, as most participants identified themselves as atheistic, agnostic, or ‘none.’ This moral domain has been further criticized, as it has been claimed that ‘purity’ is a descriptive label, and does not reflect a form of moral processing [65]. Future research could explore the relationship between the sanctity of the body and the self for metal fans, particularly for those that prefer immoral/vulgar lyrics.

A preference for lyrics about embracing metal culture & fun, which include themes like unification and loyalty, was associated with higher scores on the moral domains for authority/subversion, group loyalty, care/harm, and sanctity/degradation. It is expected that lyrics about loyalty would be associated with higher levels of loyalty as a moral foundation, which would extend into the authority moral domain, since this shows an appreciation of leadership and followship, as well as a respect for traditions. These lyrics celebrate metal culture, which might extend to a more formal view of metal culture, via respect for traditions, loyalty to the metal community, increased levels of caring, and more common views on purity compared to those who prefer vulgar/immoral lyrics and more extreme metal subgenres. This is a direction that future research could further explore. Lyrics about honour and pride include sentiments that fit well into a worldview that has structure and respect for that structure.

A preference for lyrics about history, mythology, and nature, which include lyrics about war, patriotism, and martyrdom, was positively associated with the group loyalty moral foundation. This association is reasonable, as lyrics about war can emphasize themes such as loyalty to a nation, regime, or historical entity, so individuals who enjoy these are likely seek out lyrics about loyalty as this is a moral principle important to them.

Having a preference for lyrics about science and science fiction only had a relationship with the care/harm moral domain. These are likely lyrics that are more morally neutral, which might explain the lack of an association with other moral domains. The association between science and science fiction lyrics and the moral foundation that focuses on empathy and struggle is not an intuitive one, so future research could explore this relationship by encompassing preferences for this sort of content in other forms of media, such as science fiction films.

Personality traits also had a relationship with lyrical preferences, including vulgar/immoral lyrical preferences negatively relating to agreeableness. People that enjoyed lyrics about embracing metal culture and fun had personality traits that reflected being more extraverted and agreeable, so this lyrical style that embraces activities with groups and friends is consistent with being outgoing, sympathetic, and trusting of others. Preferring lyrics about the human experience was positively related to being more agreeable, neurotic, and open to experience, showing that choosing to listen to emotional lyrics about human experiences is often consistent with having a personality associated with feelings like anxiety, depression, and loneliness. In other words, there was consistency between the lyrical subject matter and the emotional experiences of the person. Similarly, choosing to listen to lyrics about history, nature, and mythology was associated with higher levels of neuroticism and openness to experience. Lastly, enjoying lyrics about science & science fiction were only related to higher levels of openness to experience. Openness to experience is likely associated with lyrics about history and science fiction because these are lyrical topics that describe experiences that might be far from the user’s everyday experiences, indicating a preference towards lyrics that have interesting and often unfamiliar narratives that satiates their openness and desire for new experiences.

These relationships were given further clarification by investigating the extent to which moral reasoning and personality traits explained lyrical preferences. It was found that moral foundations do explain a unique and significant portion of the variance in lyrical preferences that was not already accounted for by personality traits. For example, preferring lyrics about human struggle was related to the moral foundation for care in addition to higher levels of neuroticism and agreeableness. In this instance, an individual that has higher levels of care and empathy involved in how they morally reason might also prefer lyrics about human emotions and struggles that similarly use their ability to be empathetic, since some of their personality traits (neuroticism) suggest that a tendency towards emotional instability.

In relation to the insights from moral panic theory, this study clarifies the direction between moral reasoning and lyrical preferences adding support to the hypothesis that lyrical preference reflect pre-existing moral foundations and personality traits, rather than lyrics leading to a ‘corruption’ of morality. This is consistent with previous findings showing that those who perform acts of violence seek out lyrics that justify their pre-existing beliefs about violence [4].

This study has also brought insights to the metal studies literature, showing that adhering to a metal subgenre has significant implication. For example, black metal fans had lower levels in the sanctity/purity moral domain, which is consistent with the frequently anti-religious message of black metal culture [66].

A few limitations should be noted. First, the moral foundations subscales had slightly lower internal reliabilities than anticipated. It is worth nothing that recently, Moral Foundations Theory (MFT) has been criticized for how difficult it is to replicate across cultures [67]. These limitations might extend into metal culture, in which case MFT might not be the ideal way to explore the moral reasoning of people within metal music culture. Further, the lyrical factor scale developed here comes with its own limitations. It is not expected that the factors presented would be universal across every music culture since lyrical themes and meanings vary across cultural contexts. Although the different types of lyrics could be used in the study of other music cultures, it is likely that the factor structure of the scale would be different. For instance, gang-related activities fall under the vulgar/immoral factor for metal fans, but they might not fall into the same factor in hip hop music, since lyrical topics like Satanism (also part of the vulgar/immoral factor) probably don’t appeal to the same types of hip hop fans as gang-related lyrics. A future study could investigate the degree to which lyrics are interpreted as entertaining, relational, or as a statement of endorsement towards a certain perspective (e.g., pro-violence). This meaning-making approach to lyrics would allow for understanding the role and functions of lyrical preferences, with some functional possibilities including escapism, coping, or feeling like someone else understands a user’s emotional turmoil. Other future studies could evaluate how behaviour directly relates to moral reasoning and media preferences, since it is known that moral foundations don’t always correlate with moral behaviours [68]. Whereas it is the case that violent media, such as video games [28, 29], can reduce violent behaviours, a future study could see if listening to music with violent lyrical themes serves a similar function.

This study, which explored the relationship between lyrical preferences, moral preferences and personality traits will hopefully add more nuance to the discussion of types of music and their association with moral and immoral behaviours. We suggest that lyrical preferences might originate in pre-existing characteristics, including moral reasoning styles and personality traits. This evidence can be added to that of other precursors for media preferences, including emotional vulnerability/relatability [1], personality factors [2, 3], and pre-existing ideology [4]. Given this, it is hoped that future associations between media (not limited to metal music), and behaviour will take into account these psychological factors, since there is now evidence that moral orientation is as similarly fundamental as personality traits in predicting media preferences.

Risk attitude was an important reason why certain women did not alter their fertility after the collapse of Communism in 1989; this preference for risk could explain their children criminal propensity

Chevalier, Arnaud and Marie, Olivier, Risky Moms, Risky Kids? Fertility and Crime after the Fall of the Wall (December 2019). CEPR Discussion Paper No. DP14251, https://ssrn.com/abstract=3518590

Abstract: We study the link between parental selection and child criminality. Following the collapse of the communist regime in 1989, the number of births halved in East Germany. These cohorts became markedly more likely to be arrested as they grew up in reunified Germany. This is observed for both genders and all offence types. We highlight risk attitude as an important reason why certain women did not alter their fertility decisions during this time of economic uncertainty. We also show that this preference for risk was then strongly transmitted to their children which may in turn explain their high criminal propensity.

Keywords: crime, economic uncertainty, Fertility, parental selection, risk attitude
JEL Classification: J13, K42

All the Dark Triad & Some of the Big Five Traits Are Visible in the Face: Inferring personality from faces without any concrete source of information could be an evolutionarily adaptive trait

Alper, Sinan, Fatih Bayrak, and Onurcan Yilmaz. 2020. “All the Dark Triad and Some of the Big Five Traits Are Visible in the Face.” PsyArXiv. January 27. doi:10.31234/osf.io/c3ngz

Abstract: Some of the recent studies suggested that people can make accurate inferences about the level of the Big Five and the Dark Triad personality traits in strangers by only looking at their faces. However, later findings provided only partial support and the evidence is mixed regarding which traits can be accurately inferred from faces. In the current research, to provide further evidence on whether the Big Five and the Dark Triad traits are visible in the face, we report three studies, two of which were preregistered, conducted on both WEIRD (the US American) and non-WEIRD (Turkish) samples (N = 880). The participants in both US American and Turkish samples were successful in predicting all Dark Triad personality traits by looking at a stranger’s face. However, there were mixed results regarding the Big Five traits. An aggregate analysis of the combined dataset demonstrated that extraversion (only female), agreeableness, and conscientiousness were accurately inferred by the participants in addition to the Dark Triad traits. Overall, the results suggest that inferring personality from faces without any concrete source of information would be an evolutionarily adaptive trait.

Supplementary materials: https://osf.io/dbxe5/?view_only=2540de9ebdcf448cbf564efb1c721a43

46% of subjects choose to ignore calorie information, motivated by optimal expectations – subjects choose strategic ignorance so that they can downplay the probability of their preferred meal being high-calorie

Strategic ignorance of health risk: its causes and policy consequences. Jonas Nordstrom et al. Behavioural Public Policy, January 27 2020. https://doi.org/10.1017/bpp.2019.52

Abstract: We examine the causes and policy implications of strategic (willful) ignorance of risk as an excuse to over-engage in risky health behavior. In an experiment on Copenhagen adults, we allow subjects to choose whether to learn the calorie content of a meal before consuming it and then measure their subsequent calorie intake. Consistent with previous studies, we find strong evidence of strategic ignorance: 46% of subjects choose to ignore calorie information, and these subjects subsequently consume more calories on average than they would have had they been informed. While previous studies have focused on self-control as the motivating factor for strategic ignorance of calorie information, we find that ignorance in our study is instead motivated by optimal expectations – subjects choose ignorance so that they can downplay the probability of their preferred meal being high-calorie. We discuss how the motivation matters to policy. Further, we find that the prevalence of strategic ignorance largely negates the effects of calorie information provision: on average, subjects who have the option to ignore calorie information consume the same number of calories as subjects who are provided no information.

Rats: The curse of the yo-yo effect ("weight cycling"), rapid weight gains after a diet, fails to materialize

Effects of multiple cycles of weight loss and regain on the body weight regulatory system in rats. Jennifer L. Rosenbaum, R. Scott Frayo, Susan J. Melhorn, David E. Cummings, and Ellen A. Schur. American Journal of Physiology-Endocrinology and Metabolism, Oct 24 2019. https://doi.org/10.1152/ajpendo.00110.2019

Abstract: We studied the effects of multiple cycles of weight loss and regain on the defended body weight in rats. Thirty-six male Wistar rats were divided into three weight-matched groups: weight cyclers (n = 18), ad libitum-fed controls (n = 9), and maturity controls (n = 9). Cyclers underwent four rounds of 20% weight loss from 50% caloric restriction, each cycle followed by recovery to stable plateau weight on ad libitum feeding. Controls ate ad libitum. Maturity controls ate ad libitum and then weight cycled the final two rounds to evaluate the effect of age in later cycles. Cyclers’ postdiet plateau weight became progressively lower than that of controls. With each weight loss, ghrelin increased, while insulin and leptin decreased; the magnitude of these changes did not differ across cycles. After four rounds, cyclers’ weight (504 ± 7 vs. 540 ± 22 g; P < 0.05) and percent body fat (11.7 vs. 15.2%; P < 0.05) were lower than in controls. After a 4-mo follow-up period of ad libitum feeding, cyclers maintained a lower total fat-pad mass versus controls (8.6 ± 0.5 vs. 15.9 ± 3.6 g; P < 0.01) and a lower glucose area-under-the-curve on oral glucose tolerance tests (P < 0.05). Repeated weight-loss cycles exerted positive effects, durably lowering defended levels of body adiposity and improving glucose tolerance.

When Deliberation Produces Persuasion rather than Polarization: Measuring and modeling Small Group Dynamics in a Field Experiment

When Deliberation Produces Persuasion rather than Polarization: Measuring and modeling Small Group Dynamics in a Field Experiment. Kevin Esterling, Archon Fung & Taeku Lee. British Journal of Political Science, Dec 2019, https://doi.org/10.1017/S0007123419000243

Abstract: This article proposes a new statistical method to measure persuasion within small groups, and applies this approach to a large-scale randomized deliberative experiment. The authors define the construct of ‘persuasion’ as a change in the systematic component of an individual's preference, separate from measurement error, that results from exposure to interpersonal interaction. Their method separately measures persuasion in a latent (left-right) preference space and in a topic-specific preference space. The model's functional form accommodates tests of substantive hypotheses found in the small-group literature. The article illustrates the measurement method by examining changes in study participants' views on US fiscal policy resulting from the composition of the small discussion groups to which they were randomly assigned. The results are inconsistent with the ‘law of small-group polarization’, the typical result found in small-group research; instead, the authors observe patterns of latent and policy-specific persuasion consistent with the aspirations of deliberation.

Interactive effects of tactile warmth & ambient temperature on the search for social affiliation: In colder ambient environments we report greater loneliness, & pursue both physical warmth & social affiliation

Interactive effects of tactile warmth and ambient temperature on the search for social affiliation. Adam Fay & Jon Maner. Social Psychology, Jan 2020. https://doi.org/10.1027/1864-9335/a000407

Abstract: Laboratory studies have linked variability in temperature to the psychology of social affiliation. In colder ambient environments, for example, people report greater loneliness, and they pursue both physical warmth and social affiliation (i.e., social warmth). Here, a field experiment tested whether tactile warmth eliminates the effect of colder ambient temperatures on desires for social affiliation. Consistent with previous research, people expressed greater intentions to affiliate on colder days. However, tactile warmth eliminated this effect. On colder (but not warmer) days exposure to a tactile warmth manipulation eliminated heightened desires for social affiliation. Findings suggest that seemingly subtle changes in temperature can have important implications for the psychology of social affiliation, and such findings apply to real-world contexts outside the laboratory.

Preferences for conflict & cooperation are systematically different for men & women; the increasing enfranchisement of women, not merely the rise of democracy, is the cause of the democratic peace

The Suffragist Peace. Joslyn N. Barnhart, Allan Dafoe, Elizabeth N. Saunders, Robert F. Trager. , February 21, 2018. http://www.roberttrager.com/Research_files/Suffragist7.pdf

Abstract: Preferences for conflict and cooperation are systematically different for men and women.
At each stage of the escalatory ladder, women prefer more peaceful options. They are less
apt to approve of the use of force and the striking of hard bargains internationally, and
more apt to approve of substantial concessions to preserve peace. They impose higher
audience costs because they are more approving of leaders who simply remain out of
conflicts, but they are also more willing to see their leaders back down than engage in
wars. Unlike men, most women impose audience costs primarily because a leader behaved
aggressively in making a threat, not because the leader endangered the states bargaining
reputation through behaving inconsistently. Many of these differences, and possibly all,
span time periods and national boundaries. Women have been increasingly incorporated
into political decision-making over the last century through suffragist movements, raising
the question of whether these changes have had effects on the conflict behavior of nations
consistent with their large effects in other areas, such as the size and competencies of
governments. We find that the evidence is consistent with the view that the increasing
enfranchisement of women, not merely the rise of democracy itself, is the cause of the
democratic peace.

Conclusion

The results above provide evidence that the divergent preferences of the sexes translate into a
pacifying effect when women’s influence on national politics grows. The magnitude of this correlation
is substantial, on par with the largest effects uncovered in the empirical literature on international
relations. There remains much to understand about these political processes, however. The results
presented above are consistent with greater female influence directly through voting, but perhaps
also consistent with influence exercised through other societal channels whose existence correlates
with female franchise. Another alternative explanation for our findings may be that suffrage is
confounded with liberal institutions and attitudes. While this possibility cannot be fully ruled out,
we have illustrated the shortcomings of the liberal institutions argument in a variety of ways. The
concerns of some scholars about the democratic peace may nevertheless apply to the argument we
make here. To address these, we have shown that our findings are robust to a variety of specifications.
We look forward to further investigation in these areas.
At the individual level, the evidence of a gender gap in so many existing survey experiments
suggests that scholars should explore how men and women respond to different frames or primes.
Such evidence would help illuminate how politicians might frame arguments for war or even choose
to use force in different contexts depending on the constraint of women’s more pacific preferences,
or the necessity of expending political capital to overcome those constraints. The exploration of
heterogeneous treatment effects is beyond the scope of this paper but a logical avenue for future
research.
The links in the aggregation chain from the individual level to national policy and international
interactions are also ripe for further exploration. There are potentially many paths from female
suffrage to women’s preferences influencing national policy and international outcomes. Some might
be direct, for example if interest groups are able to exert direct pressure on politicians; some might
be more indirect, for instance if institutional and electoral incentives in some countries make women
a particularly important voting bloc. In the latter case, politicians may anticipate the reactions
of female voters, either by consciously considering women’s lower baseline preference for war or by
treating it as one of part of a package of preferences. At the level of strategic interaction between
states, process tracing might illuminate whether leaders in one state actively consider the extension
of suffrage in adversary states when engaged in a crisis. More fine-grained analysis of how leaders
seek to accommodate women’s preferences in the wars they do fight could also follow, including an
examination of other dependent variables such as war duration, casualties, or military strategy.
Yet another avenue for future research concerns the potentially differing effects of female enfranchisement and female political leadership. While this study focuses on the former, others have
examined the latter, and some evidence exists that female leaders are more willing to participate
in international conflicts (Dube and Harish 2017). Given the on average individual level differences
between the sexes, this may be considered surprising. Future research should probe the extent to
which this tension is explained by one of two factors. The first is whether female political leaders
are systematically different from female population averages in ways that relate to political decisions
to engage in conflict (Fukuyama 1998, 32). The second is the extent to which female leaders, who
have often been a gender minority among their peers, have been influenced by incentives to mimic or
even exceed the aggressive norms of male peers (Goldstein 2003, 124-5. Doing otherwise might have
been interpreted as a form of “weakness” in the conduct of foreign affairs.33 In effect, as Ehrenreich
(1999) point out, the “tough” international actions of Indira Gandhi and Margaret Thatcher may
have been a form of “male posturing.”34
As the field of international relations has returned to studying individuals and their preferences
over foreign policy and international issues, the long-understood gender gap has been glossed over,
if acknowledged at all. Yet this persistent feature of individual preferences over war and peace
changes the composition of the electorate in states that give women the vote. This article represents
an important step in establishing the link, across space and time, between the gender gap at the
individual level and peace at the international level. Democracy gives the public a voice, but the
public is not homogeneous. This article suggests that women’s preferences exert a significant and
independent effect on state behavior in war, conditional on the existence of political institutions
that allow women’s voices to be heard. Early suffragist movements, including those that successfully
expanded suffrage following the First World War, were closely linked to peace movements (Goldstein
2003, 322-31). They hoped to make world politics more pacific by giving women greater say in
political affairs via the vote; their hopes were fulfilled.

Altruistic behaviors relieve physical pain

Altruistic behaviors relieve physical pain. Yilu Wang et al. PNAS January 14, 2020 117 (2) 950-958. https://doi.org/10.1073/pnas.1911861117

Significance: For centuries, scientists have pondered why people would incur personal costs to help others and the implications for the performers themselves. While most previous studies have suggested that those who perform altruistic actions receive direct or indirect benefits that could compensate for their cost in the future, we offer another take on how this could be understood. We examine how altruistic behaviors may influence the performers’ instant sensation in unpleasant situations, such as physical pain. We find consistent behavioral and neural evidence that in physically threatening situations acting altruistically can relieve painful feelings in human performers. These findings shed light on the psychological and biological mechanisms underlying human prosocial behavior and provide practical insights into pain management.

Abstract: Engaging in altruistic behaviors is costly, but it contributes to the health and well-being of the performer of such behaviors. The present research offers a take on how this paradox can be understood. Across 2 pilot studies and 3 experiments, we showed a pain-relieving effect of performing altruistic behaviors. Acting altruistically relieved not only acutely induced physical pain among healthy adults but also chronic pain among cancer patients. Using functional MRI, we found that after individuals performed altruistic actions brain activity in the dorsal anterior cingulate cortex and bilateral insula in response to a painful shock was significantly reduced. This reduced pain-induced activation in the right insula was mediated by the neural activity in the ventral medial prefrontal cortex (VMPFC), while the activation of the VMPFC was positively correlated with the performer’s experienced meaningfulness from his or her altruistic behavior. Our findings suggest that incurring personal costs to help others may buffer the performers from unpleasant conditions.

Keywords: altruistic behaviorphysical painmeaningfulnessfunctional MRI

Check also Most research has found that people exhibit altruism towards attractive people, suggesting altruistic behavior is driven by mate choice motivation:

The role of prosocial behaviors in mate choice: A critical review of the literature. Manpal Singh Bhogal, Daniel Farrelly, Niall Galbraith. Current Psychology, May 27 2019. https://www.bipartisanalliance.com/2019/05/most-research-has-found-that-people.html

Supporters of the Republican Party have become much more skeptical of the science of climate change since the 1990s, maybe as a backlash to out-group cues from Democratic elites

Merkley, Eric, and Dominik Stecula. 2020. “Party Cues in the News: Democratic Elites, Republican Backlash and the Dynamics of Climate Skepticism.”  British Journal of Political Science. Preprint January 25. doi:10.31219/osf.io/azrxm

Abstract: Supporters of the Republican Party have become much more skeptical of the science of climate change since the 1990s. We argue that backlash to out-group cues from Democratic elites played an important role in this process. We construct aggregate measures of climate skepticism from nearly 200 public opinion polls at the quarterly level from 2001 to 2014 and at the annual level from 1986 to 2014. We also build time series measures of possible contributors to climate skepticism using an automated media content analysis. Our analyses provide evidence that cues from party elites – especially from Democrats – are associated with aggregate dynamics in climate change skepticism including among supporters of the Republican Party. We then conduct a party cue survey experiment on a sample of 3,000 Americans through Amazon Mechanical Turk to provide more evidence of causality. Together, these results draw attention to the importance of out-group cue-taking and suggest we should see climate change skepticism through the lens of elite-led opinion formation.


Discussion
Climate scientists, politicians, and political scientists alike have been perplexed that a sizable portion of the American public rejects climate science, particularly among Republican Party supporters. Some have pointed to the role of organized climate denialists and the prevalence of ‘false balance’ in news coverage, others have highlighted the importance of ideology and media framing. Taking a back seat until recently has been the role of party elites. All of these factors could very well influence climate attitudes in the isolation of a survey experiment, but this does not mean they are meaningful drivers of the dynamics of American climate skepticism. We believe scholars need to also examine over time dynamics in the news media environment to examine this question, which has been neglected thus far in research. This paper situates climate change polarization in the larger literature on citizen cue-taking, opinion formation and persuasion. We argue that out-group cues from Democratic elites caused attitudinal backlash among Republican voters, reflected in their growing embrace of climate skepticism. The role of out-group cues in repelling partisan citizens has been less prominent in literature largely focused on persuasion by in-group elites (Cohen 2003; Kam 2005; Mondak 1993), though the importance of out-group elites have recently come to scholarly attention in the United States (Goren et al. 2009; Nicholson 2012). Our study provides more evidence of the central importance of out-group cues on a pressing and important national issue by marshaling a unique combination of text analysis, time series modeling, and experiments. We find that the most consistent factor that predicts aggregate patterns of climate skepticism in the public, and among Republican supporters specifically, are cues from Democratic party elites. We find that Democratic elite cues lead rather than follow public opinion on this topic (H1) and that they are contemporaneously correlated with public opinion even after controlling for other factors scholars have deemed important in shaping attitudes towards climate change (H2). These findings are supported by our survey experiment. We find that polarizing party cues from Democratic (and Republican) elites increase climate skepticism among Republican Party supporters (H3). We found this to be the case with thin treatments and after decades of partisan polarization has already occurred. We did not find a consistently similar effect among Democratic Party supporters, though we must sound a word of caution on this latter point. It is possible these results were hampered by a ceiling effect – Democratic supporters are already very supportive of the climate change consensus, so it is possible our treatments could not move the needle any further. The backlash exhibited by Republican respondents to Democratic elite cues rivals the persuasive
power of in-group cues from Republican elites in our sample, but it also appears to be attenuated by consensus cues signaling agreement between Democratic and Republican elites on climate science and the need for mitigation. In short, we show that the story behind climate change polarization is similar to other political issues of the day: members of the public were exposed to a large volume of partisan messages on climate change as the issue grew in salience – in this case primarily from Democratic elites – and formed their opinions accordingly. This work joins an emerging literature on the role of the media and elite cues in climate change polarization (Carmichael and Brulle 2017; Guber 2013; Merkley and Stecula 2018; Tesler 2017), work showing the persuasive influence of out-group party cues (Berinsky 2009; Bischof and Wagner 2019; Feddersen and Adams 2018; Goren et al. 2009; Nicholson 2012). There are a number of important implications from these findings. First, party elites who strongly identify with the scientific consensus on climate change or other issues must weigh the costs and benefits of aggressively communicating their stance in the mass media. The rising prevalence of party elites in news coverage of climate change was inevitable at some level because of the need for large-scale policy action, but this finding has implications for other scientific issues, such as the safety of genetically modified organisms (GMOs) and vaccines. Efforts to bring these issues into the realm of elite conflict will almost surely lead to polarization as an unanticipated consequence. Second, emphases on ideology and motivated cognition, while important to understanding why persuading Republicans and conservatives about the perils of climate change is a tough task at present, is perhaps of more limited utility in helping us explain how we got to this point in the first place. Republican supporters were not always so skeptical of climate change. They listened to, and formed opinions based on, signals from trusted opinion leaders within their communities. By viewing the roots of climate change skepticism primarily in deep-seated ideological and value constructs, we minimize the degree to which elites can shape those constructs. It also means that these elites can turn the tide by taking climate change out of the realm of hyper-partisan conflict. Although our experiment did not find a de-polarizing effect of a consensus cue treatment, a stronger treatment featuring highly respected Republican officials may have more success. Lastly, and relatedly, the potentially prominent role of party elites in the formation of public attitudes on climate change suggests scholars should invest less time and resources in identifying messaging strategies to mobilize support for the climate consensus, and more on understanding the motivations and behavior of party elites. Finding ways to mobilize an elite consensus across partisan
lines is perhaps the most promising strategy to bring public opinion alongside the scientific consensus on climate change.

It Happened to a Friend of a Friend: Inaccurate Source Reporting in Rumor Diffusion

Altay, Sacha, Nicolas Claidière, and Hugo Mercier. 2020. “It Happened to a Friend of a Friend: Inaccurate Source Reporting in Rumor Diffusion.” PsyArXiv. January 25. doi:10.31234/osf.io/5czka

Abstract: Culturally successful rumors are commonly attributed to a credible friend of a friend, but little is known about how this sourcing can boost rumors’ propagation. In four online experiments (N = 2024) we found that attribution to a credible friend of a friend increased a rumor’s perceived plausibility, and participants’ willingness to share it. Moreover, the credible friend of a friend attribution remained stable across multiple transmissions, instead of the number of friends mentioned increasing with each transmission. The main alternative was to only mention a friend (without credibility attribution). Even though this latter alternative dominated linear transmission chains, introducing a degree of redundancy allows the credible friend of a friend to persist or dominate. We suggest that the preference for attributing rumors to a credible friend of a friend reflects reputation management considerations.

Many of our smiles in everyday life are only posed and signify something very different from joy and happiness

Emotional expressions in human and non-human great apes. Mariska E. Kret et al. Neuroscience & Biobehavioral Reviews, January 25 2020, https://doi.org/10.1016/j.neubiorev.2020.01.027

Highlights
• Emotional expressions are frequently used in all great ape species.
• Compared to apes, humans have evolved communicative faces where all the expressive parts are emphasized.
• Also in great apes species-specific facial characteristics have evolved to enhance communication.
• Smiles have been ritualized to a greater extent in humans than in apes, laughter is similar and seen in comparable contexts.
• Great apes do have voluntary control over some expressions.

Abstract: Humans and great apes are highly social species, and encounter conspecifics throughout their daily lives. During social interactions, they exchange information about their emotional states via expressions through different modalities including the face, body and voice. In this regard, their capacity to express emotions, intentionally or unintentionally, is crucial for them to successfully navigate their social worlds and to bond with group members. Darwin (1872) stressed similarities in how humans and other animals express their emotions, particularly with the great apes. Here, we show that emotional expressions have many conserved, yet also a number of divergent features. Some theorists consider emotional expressions as direct expressions of internal states, implying that they are involuntary, cannot be controlled and are inherently honest. Others see them as more intentional and/ or as indicators of the actor’s future behavior. After reviewing the human and ape literature, we establish an integrative, evolutionary perspective and provide evidence showing that these different viewpoints are not mutually exclusive. Recent insights indicate that, in both apes and humans, some emotional expressions can be controlled or regulated voluntarily, including in the presence of audiences, suggesting modulation by cognitive processes. However, even non-intentional expressions such as pupil dilation can nevertheless inform others and influence future behavior. In sum, while showing deep evolutionary homologies across closely related species, emotional expressions show relevant species variation.

Keywords: emotional expressionsgreat apescomparative psychologycognitive controlevolution

Political leanings are the strongest predictors of climate change beliefs, particularly among the more knowledgeable

Climate Change: A Partisan and Polarized Issue in the United States. Risa Palm, Toby Bolsen. Climate Change and Sea Level Rise in South Florida pp 15-40, January 2 2020. https://link.springer.com/chapter/10.1007/978-3-030-32602-9_3

Abstract: Climate change has become a politically polarized issue within the past 30 years, as interest groups and certain political leaders sought to dispute the growing scientific consensus about its causes and impacts. This chapter synthesizes a large body of survey, experimental and methodological literature that places the empirical study of South Florida in context. Past survey research has shown conclusively that party identification and ideology are the strongest predictors of climate change beliefs of Americans. Other predictors that are less consistent include demographic characteristics, cultural worldviews and personal experience. Survey and laboratory research has been directed at understanding the processes involved in accepting or denying messages about climate change. Among the findings are that strategically framed messages can shift opinion, that a belief in scientific consensus about climate change may increase acceptance of its reality, that prior beliefs, group identities and cultural worldviews moderate the acceptance of climate change information through motivated reasoning, and that best practices involve describing climate change as a personal risk, using social group norms to convince skeptics, and emphasizing social consensus on the issue. Prior research suggests that a message about environmental risk that is local and specific will be relatively more effective, particularly when the immediate threat is already visible.

Keywords: Motivated reasoning Framing Partisanship Public opinion Consensus Polarization Risk communication

Gun owning women are more engaged & participatory in politics than non-owning women; often feel empowered by owning a gun; & are more supportive of death penalty & military use than non-owners

Female Firepower: Exploring the Politics of Gun Ownership and Gender. Alexandra Terese Middlewood. University of Arkansas, PhD Thesis, May 2019.
https://kuscholarworks.ku.edu/bitstream/handle/1808/29891/Middlewood_ku_0099D_16519_DATA_1.pdf?sequence=1&isAllowed=y

Abstract: Pro-gun organizations have made great strides in mobilizing women and have been successful in inculcating women into gun culture. This raises questions about the intersection of gun ownership, an emerging political identity, and gender. Thus, this dissertation explores the cross pressures women face from their gun ownership status and the political consequences of such cleavages using an intersectional approach. First, I examine the effect of gun ownership on women’s political participation and engagement. I find gun owning women to be more engaged and participatory than non-owning women, and find them to be particularly motivated by gun issues. Second, I study the effect of gun ownership on women’s feelings of safety in public spaces where firearms are present. Women often feel empowered by owning a gun, and I find gun owning women to be much less averse to firearms than non-owning women. Furthermore, in some cases, women owners were even less averse than their male counterparts. Lastly, I examine the effect of gun ownership on women’s attitudes about use of force policies, namely the death penalty and the use military force. Here, gun owning women are more supportive of such policies than non-owners, and gun ownership is found to mitigate the expected gender gap in attitudes on these issues. I conclude by addressing the importance of these findings for the literature and for politics, the limitations of these studies, and avenues for future research.

People perform better on a cognitive task when they know its end; asymptotic performance level reflects ability as well as effort-allocation decision

Cognitive performance is enhanced if one knows when the task will end. Maayan Katzir Aviv, Emanuel Nira Liberman. Cognition, Volume 197, April 2020, 104189. https://doi.org/10.1016/j.cognition.2020.104189

Highlights
• People perform better on a cognitive task when they know its end.
• Asymptotic performance level reflects ability as well as effort-allocation decision.
• We theorize that opportunity cost (OC) reduces near a salient end-point.
• By reducing OC, salient end-points reduce mental fatigue/experienced effort.

Abstract: In two studies, participants performed a switching task, and we provided to only half of them feedback on goal progress (how much of the task still remains). Importantly, this feedback did not inform participants on how well they performed. We found that participants in the feedback condition achieved a higher asymptotic level of performance, reported less fatigue and took shorter breaks between blocks compared to the control condition. These results suggest that asymptotic level of performance reflects not only ability (as is commonly assumed in the literature) but also motivation. We suggest that when people know when a focal task would end, they invest more effort in it because foregoing other activities becomes less costly (i.e., opportunity cost of engaging in the focal activity decreases) and because knowing when a task would end frees the actor from the need to conserve effort. These results suggest a simple, effective and costless way to improve cognitive performance that may be applied in educational and organizational settings.

Keywords: Effort allocationGoal gradientOpportunity costCognitive resources

The Architect Who Lost the Ability to Imagine: The Cerebral Basis of Visual Imagery After a Cerebral Artery Stoke

Thorudottir, S.; Sigurdardottir, H.M.; Rice, G.E.; Kerry, S.J.; Robotham, R.J.; Leff, A.P.; Starrfelt, R. The Architect Who Lost the Ability to Imagine: The Cerebral Basis of Visual Imagery. Brain Sci. 2020, 10, 59. https://www.mdpi.com/2076-3425/10/2/59

Abstract: While the loss of mental imagery following brain lesions was first described more than a century ago, the key cerebral areas involved remain elusive. Here we report neuropsychological data from an architect (PL518) who lost his ability for visual imagery following a bilateral posterior cerebral artery (PCA) stroke. We compare his profile to three other patients with bilateral PCA stroke and another architect with a large PCA lesion confined to the right hemisphere. We also compare structural images of their lesions, aiming to delineate cerebral areas selectively lesioned in acquired aphantasia. When comparing the neuropsychological profile and structural magnetic resonance imaging (MRI) for the aphantasic architect PL518 to patients with either a comparable background (an architect) or bilateral PCA lesions, we find: (1) there is a large overlap of cognitive deficits between patients, with the very notable exception of aphantasia which only occurs in PL518, and (2) there is large overlap of the patients’ lesions. The only areas of selective lesion in PL518 is a small patch in the left fusiform gyrus as well as part of the right lingual gyrus. We suggest that these areas, and perhaps in particular the region in the left fusiform gyrus, play an important role in the cerebral network involved in visual imagery.

Keywords: visual imagery; stroke; posterior cerebral artery; aphantasia; prosopagnosia; visual perception

Trajectories of Migrant Male Sex Workers in Paris: He are too often presented as street-based seller of sexual services whereas many of them actually perform intimacy and companionship

Selling Sex and Intimacy in Paris: Trajectories of Migrant Male Sex Workers. Kostia Lennes. 5th European Geographies of Sexualities Conference, Prague Sep 2019. Ed. Michal Pitoňák, Lukáš Pitoňák. https://www.academia.edu/40732506

ABSTRACT: Although further attention has been paid to male sex workers in the past two decades, most scholars who discussed this issue in relation to migration did so through the lens of sex tourism (Allen 2007; Mitchell 2015). In this perspective, male sex workers, who are mostly locals, are therefore excluded from the focus on mobilities. On the other hand, research on migrant sex workers in global cities have focused almost exclusively on women (Chin 2014), with a few notable exceptions (Mai 2018). This proposal aims to fill this gap by presenting the first insights of an ongoing doctoral research project on non-trafficked male sex workers who migrated to Paris in order to perform sexual labour. Coming from different regions of the world, these men have various backgrounds and are often on the move between several cities, in Europe and beyond. Drawing on anthropological accounts on globalisation and cosmopolitanism, the main objective of this research project is to grasp the trajectories of these men who have come to sell sex and intimacy in the French global city. Furthermore, particular attention will be paid to other ways of commodifying intimacy (Constable 2009) than sexual contacts strictly speaking, which is still an overlooked issue as Sanders (2008) and Weitzer (2009) noted. Indeed, the figure of the migrant sex worker is too often presented as a streetbased seller of sexual services whereas many of them actually perform intimacy and companionship, thus redefining contemporary forms of sex work among migrants.

Keywords: male sex workers; cosmopolitanism; commodification of intimacy; sexual labour

The overweight, those carrying a large bag and females avoided both stair climbing and descent more frequently than their comparison groups

Eves FF (2020) When weight is an encumbrance; avoidance of stairs by different demographic groups. PLoS ONE 15(1): e0228044, Jan 24 2020. https://doi.org/10.1371/journal.pone.0228044

Abstract
Background Locomotion is an energy costly behaviour, particularly when it entails raising weight against gravity. Minimization of locomotor costs appears a universal default. Avoidance of stair climbing helps humans minimise their energetic costs. In public access settings, demographic subgroups that raise more ‘dead’ weight than their comparison groups when climbing are more likely to avoid stairs by choosing the escalator. Individuals who minimise stair costs at work, however, can accumulate a deficit in energy expenditure in daily life with potential implications for weight gain. This paper tests the generality of avoidance of stairs in pedestrians encumbered by additional weight in three studies.

Methods Pedestrian choices for stairs or the alternative were audited by trained observers who coded weight status, presence of large bags and sex for each pedestrian. Sex-specific silhouettes for BMIs of 25 facilitated coding of weight status. Choices between stairs and a lift to ascend and descend were coded in seven buildings (n = 26,981) and at an outdoor city centre site with the same alternatives (n = 7,433). A further study audited choices to ascend when the alternative to stairs was a sloped ramp in two locations (n = 16,297). Analyses employed bootstrapped logistic regression (1000 samples).

Results At work and the city centre site, the overweight, those carrying a large bag and females avoided both stair climbing and descent more frequently than their comparison groups. The final study revealed greater avoidance of stairs in these demographic subgroups when the alternative means of ascent was a sloped ramp.

Discussion Minimization of the physiological costs of transport-related walking biases behaviour towards avoidance of stair usage when an alternative is available. Weight carried is an encumbrance that can deter stair usage during daily life. This minimization of physical activity costs runs counter to public health initiatives to increase activity to improve population health.

Discussion

As with lifts, avoidance of stairs by choosing a sloped ascent was frequent. The lower rates of avoidance in Chamberlain Square than the station may reflect the greater detour in the square to choose the slope. Avoidance in the square required 76m of walking versus 48.4m for the direct route across the square; at the station, the discrepancy was smaller, 46.1m versus 42.6m. Inevitably, any detour would increase journey times and, typically, pedestrians seek to minimise time and distance [14,15,23,24]. Less frequent avoidance in the square may reflect the greater temporal cost of the indirect route. Nonetheless, stairs are a more energy efficient means of raising weight against gravity than slopes of equivalent angle [29]. Avoiding stairs by choosing a slope will increase both temporal and energetic costs, unlike the reduced costs with mechanised alternatives. This result of avoidance, despite increased cost, may reflect the more gradual force production possible on the slope to achieve the ascent; the actual height of the climb was the same for both alternatives.

General discussion

The studies in this paper reveal consistent effects of demographic grouping on stair avoidance when an alternative is available. In workplaces, and at an outdoor site where the alternative was a lift, overweight pedestrians, those carrying large bags and females were more likely to avoid stairs than their comparison groups. In the final study, this pattern of avoidance occurred where the alternative method of ascent was a sloped ramp. Taken together with a previous summary of avoidance with escalators [9], these studies expand on the original question posed by Brownell and co-workers about the effects of weight status on avoidance of stair use [7,8]. Overweight pedestrians negotiating the built environment are more likely to avoid the physical activity of stair use as part of daily life than healthy weight pedestrians. So are females and those carrying large bags. A bias to minimise the costs of active transport provides a plausible explanation for this generality.

Minimizing energetic cost

During locomotion, humans naturally optimise energetic cost. They adopt a step width, step length and step frequency for walking and choose a step length and frequency for running, all of which minimise the total metabolic cost for completion of the behaviour (see [30]). Humans have an optimal speed for walking and running that minimises the energetic cost per unit distance [31,32], as do other animals [33,34]. Minimisation of transport costs may be a universal default. This minimization requires repeated iterations to optimise the behaviour. Minimisation of transport costs is learnt, linked to the changes in the visual consequences of forward motion [30,35–38]. All of the above studies were for locomotion on the level. Stair climbing, at two and half times the energetic cost of purposeful walking [2], is a metabolically costly barrier encountered during active transport. A consistent bias for pedestrians to minimise the cost incurred by climbing is evident; in shopping malls where journey time is less of an issue than in stations, 92.4% avoid stairs (n = 355,069 [9]). Raising body weight against gravity is energetically costly and appears to be minimised by other animals [39,40]. Energy expenditure serves three main functions, basal metabolic rate, diet-related expenditure on ingested food, and energy for physical activity [41]. Human basal metabolic rate requires 60% of the recommended daily intake and utilizing food a further 6–12% [41]. At least two thirds of recommended intake are required for these recurrent costs of maintaining function that must be met. The only modifiable part of the equation linking intake and expenditure is the remaining third of intake available for movements of the body; it has been estimated that 89% of these movements involve walking [41]. Transport-related walking has deep evolutionary roots. Minimising the proportion of total intake required for transport would be biologically advantageous [30–34].

Nonetheless, the final pair of studies demonstrated that avoidance was not synonymous with minimisation of expenditure. Choosing a sloped ascent increased both temporal and energetic costs. Walking up a slope allows a more gradual force production during the ascent; peak forces at the knee are reduced compared to stairs [28,29]. Similarly, a modified climbing gait in older individuals reduces the forces at the knee and the ankle to a lower proportion of their maximal capacity [42]. Older climbers have reduced resources for climbing and adopt a reduced, and more gradual, increase in force over time for each step [42]. Choosing the slope in the final pair of studies would allow individuals with reduced resources for climbing to maintain output at a lower proportion of total resources, despite increases in energetic and temporal costs. Aggregated avoidance with ramped ascent, 50.1% (95% CI = 49.3, 50.9) exceeded that when the lift was the alternative, 33.5% (95% CI = 33.0, 34.0). Preference for more gradual resource expenditure could increase avoidance when a ramp was available whereas unwillingness to wait for a lift could decrease it.

Perception of stair slope

Recent research on the perception of the slope of stairs provides clues to the mechanisms that may underlie avoidance based on climbing resources. Perception of the angle of hills and stairs is exaggerated in explicit awareness; a 10˚ hill is reported to be about 30˚ and a 23˚ staircase reported to be 45˚ [43–45]. In experimental studies, fatigue from an exhausting run [45–47], carrying extra weight [46] and depleted glucose resources [48], all result in further exaggerations of reported angle. While effects of experimental demand have been proposed as an alternative explanation [49,50], quasi-experimental studies confirmed effects of depleted resources [51] and additional weight carried [43,52] where demand was absent. Travelers waiting for their trains were recruited to complete an interview about the environment [43,51,52]; there was no experiment. Proffitt argued that perception of slope was ‘embodied’ in that resources for climbing influenced explicit perception [44]. Embodied effects of resources facilitate physical activity choices without individuals having to specifically consider resource availability [44].

Echoing the behavioural differences documented here, overweight pedestrians, those wearing heavy bags and females all reported potential climbs as steeper than their comparison groups [43,45–47,51,52]. Estimates of stair steepness scaled by the deadweight of fat mass that would be carried [51]. As noted earlier, females have, on average, a greater percentage of their weight as body fat (25%) than males (12.5%) and hence are encumbered by more deadweight [10]. Consistently, females reported slopes as steeper than males did [43,45,47,49,50]. Further, stairs were reported as steeper by pedestrians who avoided them by choosing the escalator, even when potential effects of demographics were controlled by stratified sampling and statistical adjustment [43]. Perceived steepness appears to be an environmental cue linked to resources that can deter climbing when an alternative is available [43].

At work, the stairs may not be directly visible when a lift is chosen so perception of steepness cannot directly influence choice. Nonetheless, individuals learn about the potential cost of climbing from experience, biasing subsequent choices. As resources change, behaviour, and the associated perception, echo these changes. Body mass is composed of fat free mass and fat mass. Fat free mass that provides resources for climbing was unrelated to perceived steepness [52]. Rather, it was fat mass, i.e. deadweight that must be carried, that was linked to perception [52]. Further, only changes in fat mass, not fat free mass, were related to changes in perception of steepness over a year later [52]. Similar calibration of perception occurred for changes in body size during pregnancy [53] and loss of leg strength with ageing [54]; changes without experience were ineffective [53]. Obese individuals walk less than lean participants, with daily walking distance negatively correlated with body fat [55]. In the only truly experimental study of weight change, increases in body mass, 78% of which was fat, reduced the distance walked equally for healthy and overweight participants [55]; resources changed behaviour. In both longitudinal perception studies, body change over time influenced perception [52,53]. No study has altered perception to change behaviour. The simplest conclusion is that weight carried deters behaviour [55], consistent with the direction of effects in other research [56–58]. Avoidance of stairs seems likely to be a consequence of weight carried. The role of learning in this process, and the potential mediator of perception, is unknown.

Limitations

It is a curiosity that one strength of these data, direct auditing of behaviour, is accompanied by a limitation. Auditing provides matchless accuracy about the actual behaviour performed; accelerometers, for example, cannot identify behaviour. Observational studies of stair use allow a test of the biasing effects of extra weight carried because of the ability to clearly identify the behavioural choice made. Stair climbing is a vigorous member of the family of active transport behaviours. The energetic cost of stair climbing is clear. Work done to raise weight against gravity is relatively independent of the rate of climbing. Height of the climb, not speed, primarily determines cost. Climbing at 60 steps.min-1 required 8.7 METs (Eves & White, unpublished) whereas climbing at almost twice that speed, 110 steps.min-1, cost 9.6 METs [2]. Effects of weight on the lower intensity activity of stair descent here, and on ‘objectively’ measured walking [55], physical activity [57] and sitting time [56], indicate a generalised effect of weight carried on physical activity choices. Nonetheless, auditing will imperfectly measure demographic differences. Sex is generally straightforward but weight status, and the additional weight of a large bag, must be imprecise categories, even when silhouettes optimise coding for weight status [3,21]. The commonality of effects of weight carried on avoidance across different settings, however, does not suggest imprecision in measurement has impeded the research. The fact that demographic differences in avoidance behaviour are linked to perception of an environmental cue that promotes avoidance indicates some triangulation on the question.