Humans can frequently give children to others to sustain and educate: Grandmothers can be crucial, even when alloparenting is common and breastfeeding is frequent and highly visible

Crucial Contributions: A Biocultural Study of Grandmothering During the Perinatal Period. Brooke A. Scelza, Katie Hinde. Human Nature, Volume 30, Issue 4, pp 371–397, December 4 2019. https://link.springer.com/article/10.1007/s12110-019-09356-2

Abstract: Maternal grandmothers play a key role in allomaternal care, directly caring for and provisioning their grandchildren as well as helping their daughters with household chores and productive labor. Previous studies have investigated these contributions across a broad time period, from infancy through toddlerhood. Here, we extend and refine the grandmothering literature to investigate the perinatal period as a critical window for grandmaternal contributions. We propose that mother-daughter co-residence during this period affords targeted grandmaternal effort during a period of heightened vulnerability and appreciable impact. We conducted two focus groups and 37 semi-structured interviews with Himba women. Interviews focused on experiences from their first and, if applicable, their most recent birth and included information on social support, domains of teaching and learning, and infant feeding practices. Our qualitative findings reveal three domains in which grandmothers contribute: learning to mother, breastfeeding support, and postnatal health and well-being. We show that informational, emotional, and instrumental support provided to new mothers and their neonates during the perinatal period can aid in the establishment of the mother-infant bond, buffer maternal energy balance, and improve nutritional outcomes for infants. These findings demonstrate that the role of grandmother can be crucial, even when alloparenting is common and breastfeeding is frequent and highly visible. Situated within the broader anthropological and clinical literature, these findings substantiate the claim that humans have evolved in an adaptive sociocultural perinatal complex in which grandmothers provide significant contributions to the health and well-being of their reproductive-age daughters and grandchildren.

Keywords: Cooperative breeding Breastfeeding Grandmothers Maternal and child health

Discussion

Grandmothers have long been touted as one among a suite of important alloparents in the human cooperative breeding system (Hrdy 2005; Kramer 2010). But despite their prominence in the literature, data demonstrating positive effects of grandmaternal support is somewhat equivocal. For food sharing and intergenerational transfers, grandmothers in some places play a critical role (Hawkes et al. 1997; Hooper et al. 2015), but in others their efforts are outweighed by other helpers (Kramer 2005; Kramer and Veile 2018). Similarly, the amount of direct care provided to infants and toddlers by grandmothers, compared with other allomothers, is quite variable (Kramer 2010). Despite this disparate evidence, reviews demonstrate strong and consistent patterns showing an association between presence of the maternal grandmother and improved child survival (Fox et al. 2010; Sear and Mace 2008). Taken together, these lines of evidence suggest that supplemental provisioning and childcare are just two pieces of the grandmothering puzzle. Other elements of the grandmaternal niche remain to be systematically investigated. Here we emphasize how multifaceted perinatal support has the potential to improve the health and well-being of mothers and their babies, not only expanding our understanding of grandmothers but bridging to other constructs of human evolution such as the role of emotional support and perinatal care during the difficult childbirths and challenging transitions to motherhood experienced by humans (Trevathan 2017).

Social Learning in the Perinatal Period

Here we explored the perinatal period embedded in the context of subsistence nutrition, disease ecology, energy balance, kin networks, traditional knowledge, and maternal-infant dynamics atypical of WEIRD populations (Henrich et al. 2010). Populations characterized by predominant subsistence activities and traditional sociocultural practices reveal aspects of adaptive reproductive ecology often disrupted in industrialized contexts. Importantly though, no present-day subsistence culture or population represents the human past nor exclusively occupies the environments in which humans emerged (Crittenden and Schnorr 2017; Lee 1992). From an infant’s perspective, however, the “normalized” breastfeeding dynamic of the mother-infant dyad represents the adaptively relevant environment in which the human neonate evolved. Our findings about breastfeeding difficulties and other maternal anxieties counter widely held perceptions, expectations, and attitudes suggesting that breastfeeding and infant care are intrinsic to womanhood, easily learned through exposure and observation, and only become difficult in contexts where these pathways are disrupted.

Among Himba, breastfeeding is “normalized”; breastfeeding initiation is universal and sustained for many months, nursing is on demand, and clothing does not cover breasts so nursing is highly visible. This is the cultural context in which Himba grow up. But despite this normalization and ubiquity of breastfeeding, Himba women often reported struggling in the early postpartum period following their first births. The women we interviewed spontaneously described difficulties typically encountered by women living in industrialized settings, including nipple/breast pain, difficulty with latch, and concerns about insufficient milk production (Bergmann et al. 2014; Lamontagne et al. 2008; Waller 1946; Williamson et al. 2012). While their struggles are similar, we argue that the consistent, multifaceted support and teaching that Himba grandmothers provide during the first weeks after a birth seems to have an appreciable impact on women’s ability to overcome these difficulties, going on to successfully breastfeed for months and years to come. Similarly, Himba women’s descriptions of the fear and anxiety they experienced during the early postpartum period and their lack of knowledge about basic infant care (e.g., how to hold an infant) further counter common tropes about motherhood in its “natural state.” Again, the main difference appears to be one of timescale. The consistent support that Himba women receive during the perinatal period helps them to overcome difficulties and quell their anxieties in a matter of days, whereas it is not uncommon for women in WEIRD settings to struggle for weeks, or even months, after a birth.

The rapid learning curve that Himba women describe, combined with an intensive period of perinatal co-residence and support, leads us to suggest that social learning from grandmothers and other female kin may be critical to facilitating women’s ability to successfully breastfeed and provide infant care. In some cases, Himba grandmothers were reported to provide very direct instruction. Women reported that their mothers physically and gesturally showed them how to position their babies for improved latch, provided detailed guidance on how often to feed, and explained techniques to protect infants, such as putting them to sleep on their backs and to nurse sitting up rather than lying down. Others described techniques that have presumably been developed and fine-tuned over generations, such as the postpartum steam “bath” described above, or knowledge about which foods and herbs serve as lactogogues. Our findings mirror those of other studies that have similarly shown how the presence of cultural practices and beliefs, acquired through social learning, can positively impact reproductive health. For example, several studies of pregnancy food taboos have been shown to map closely onto species that pose particular dangers to pregnant women and their fetuses (Henrich and Henrich 2010; McKerracher et al. 2016; Placek et al. 2017). Other studies have shown the importance of ideational factors, shared within groups and socially learned, to the practice of early infant care (Hadley et al. 2010; Wutich and McCarty 2008).

Further study might enhance our understanding of perinatal care as a case of social learning and answer questions we are unable to address with our current data. For example, we rely here on self-reports, which have the potential for bias and are not useful for quantifying behavior beyond coarse categories. Observational data would provide exceptional insight into the prevalence of teaching and learning behaviors and would be less subject to bias; however, such data would be very difficult to obtain. The scenarios we describe take place in intimate settings, often during the night in a private sleeping space. Nighttime observations are notoriously rare in time allocation data and present logistical and ethical challenges (Scaglion 1986). Other, less direct types of data could speak to some of these issues. For example, repeated measures of infant health and maternal pain and anxiety could track the effectiveness of grandmothers’ help, particularly in a case-control design comparing women who are and are not co-resident with their mothers after a first birth. Focal follows that concentrate on the first week or two after a birth (particularly first births) would also be extremely useful, as this would increase the chances of capturing otherwise rare instances of potential teaching and provide greater insight into how new mothers learn to breastfeed and care for their infants.

Air Filters, Pollution and Student Achievement

Gilraine, Michael. (2020). Air Filters, Pollution and Student Achievement. (EdWorkingPaper: 20-188). Retrieved from Annenberg Institute at Brown University: https://www.edworkingpapers.com/ai20-188

Abstract: This paper identifies the achievement impact of installing air filters in classrooms for the first time. To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles of the leak (but not beyond). This variation allows me to compare student achievement in schools receiving air filters relative to those that did not using a spatial regression discontinuity design. I find substantial improvements in student achievement: air filter exposure led to a 0.20 standard deviation increase in mathematics and English scores, with test score improvements persisting into the following year. Air testing conducted inside schools during the leak (but before air filters were installed) showed no presence of natural gas pollutants, implying that the effectiveness of air filters came from removing common air pollutants and so these results should extend to other settings. The results indicate that air filter installation is a highly cost-effective policy to raise student achievement and, given that underprivileged students attend schools in highly polluted areas, one that can reduce the pervasive test score gaps that plague public education.

Keywords: Air Pollution; Human Capital; Air Filters; Spatial Regression Discontinuity; Cost Effectiveness.

Explaining Fairness: Theories of genetic evolution, cultural evolution, and gene-culture coevolution identify plausible mechanisms for the evolution of fairness in humans

Explaining Fairness. Lukas Boesch & Roger Berger. Human Nature volume 30, pages398–421, November 16 2019. https://link.springer.com/article/10.1007/s12110-019-09353-5

Abstract: Fairness is undoubtedly an essential normative concept in humans and promotes cooperation in human societies. The fact that fairness exists is puzzling, however, because it works against the short-term interest of individuals. Theories of genetic evolution, cultural evolution, and gene-culture coevolution identify plausible mechanisms for the evolution of fairness in humans. Such mechanisms include kin selection, the support of group-beneficial moral norms through ethnic markers, free partner choice with equal outside options, and free partner choice with reputation as well as spite in small populations. Here, we present the results of a common-pool resource game experiment on sharing. Based on data from 37 multiethnic villages in a subsistence agricultural population in Foutah Djallon, Guinea, we show that fair behavior in our experiment increased with increasing ethnic homogeneity and market integration. Group size and kinship had the opposite effect. Overall, fair behavior was not conditional on reputation. Instead, the ability of the different village populations to support individuals’ fairness in situations lacking the opportunity to build a positive reputation varied significantly. Our results suggest that evolutionary theory provides a useful framework for the analysis of fairness in humans.

Discussion

In our experiment, fairness was influenced by some mechanisms that have been suggested in the literature. First, as expected (Table 1), the subjects’ fairness was positively influenced by the ethnic homogeneity of villages (Table 3). The predicted behavior of subjects was on average only fair in ethnically homogeneous villages (Fig. 3) and became more selfish with increasing ethnic heterogeneity. This result corroborates the existing empirical evidence regarding the influence of ethnic homogeneity on prosociality (Alesina and La Ferrara 2000; Alesina et al. 1999; Anderson and Paskeviciute 2006; Costa and Kahn 2003; Gustavsson and Jordahl 2008; Habyarimana et al. 2007; Leigh 2006; Miguel and Gugerty 2005; Newton and Delhey 2005; Pennant 2005; Putnam 2007). 

Second, as expected (Table 1), the subjects’ behavior in our experiment became increasingly fair with increasing market integration (Table 3, Fig. 3). This result confirms the positive effect of market integration on fairness found in other experimental studies (Emsinger 2004; Henrich et al. 2001, 2010).

Third, as expected (Table 1), the capacity of villages to support fairness decreased with population size (Table 3). The behavior of subjects was on average fair only for villages below 200 individuals and became selfish with increasing population size (Fig. 3). This result adds to the inconsistent experimental evidence related to the effect of population size on fairness (Henrich et al. 2010; Stahl and Haruvy 2006).

On the other hand, for some other mechanisms generally considered to be important, we found contradicting evidence. Surprisingly, the predicted positive effect of kinship on the fairness of subjects (Table 1) was not confirmed: subjects in our experiment became more selfish with increasing kinship (Table 3). Predicted behavior was on average only fair in the village populations with the lowest kinship (Fig. 3). This finding does not match the results of previous studies: although the extensive foodsharing literature widely supports a positive effect of kinship on fair or generous sharing (Essock-Vitale and McGuire 1980; Gurven 2004; Gurven et al. 2000, 2001; Nolin 2011; Patton 2005; Wiessner 2002; Ziker and Schnegg 2005), the experimental literature does not find convincing evidence for any effect of kinship on fairness (Barr 2004; Macfarlan and Quinlan 2008). Interestingly, our measure for kinship at the individual level, the proportion of the subjects’ kin group in the village population, did not provide any additional insights into the relationship between kinship and fairness (Table 3). This means that we cannot resort to mechanisms at the individual level of the subjects’ kinship to explain this unexpected finding. Two such plausible mechanisms could be the following: in villages with high kinship at the aggregate level, either subjects with high individual kinship took more than their share to redistribute it to kin afterwards, or, from the opposite point of view, subjects with low individual kinship took more than their share because they were not related to the majority of the other inhabitants of the village. Both would imply significant estimates of the measure of kinship at the individual level of the subjects (kin group): the first mechanism would imply a positive estimate, the second a negative one.

Finally, lack of an opportunity for reputation building did not lead to a general increase in selfish behavior (Table 1). Instead, the effect on fairness of such an opportunity varied significantly, depending on the village. We found the expected increase in selfish behavior in two thirds of the villages. Some individuals were extremely selfish in the treatment condition without observation. Interestingly, our experimental treatment also led to fairer, or even generous behavior (Table 3; A19 in the ESM). This result is not consistent with the broad experimental literature supporting the notion that observability of behavior triggers prosociality (Bereczkei et al. 2007, 2010; Bull and Gibson-Robinson 1981; Kurzban 2001; Milinski et al. 2002; Satow 1975; Soetevent 2005). We can only speculate about reasons for this finding. From a methodological point of view, we can think of two explanations for this finding. First, our experimental stimulus may not have been only a measure of reputation, but also of the willingness to defy instructions or the fear for punishment. Those different dimensions might have interacted and led to such a varying effect. Second, our experimental stimulus may not have worked as expected in all the villages. The villages where our experimental treatment worked as expected must have differed in some ways we did not control for from the villages where the treatment did not work as expected. In theory, an important factor is the feeling of privacy of the subjects, not only within the village communities in general, but also after the experiment, when leaving the hut with the salt: in some instances, others were waiting outside for their turn; in other cases, nobody was waiting. Unfortunately, we did not record this information. The random slopes for reputation (A19 in the ESM) and the amount of salt (A21 in the ESM) did capture such situational differences to some extent.

The results of our analysis show that the behavior of subjects in our experiment was mainly driven by the characteristics of their village (Table 3, Figs. 2 and 3). Unlike in previous studies (Cronk 2007; Henrich 2000; Paciotti and Hadley 2003; Roth et al. 1991; Tracer 2003), we did not find an effect of the subjects’ ethnicity on fairness. We believe that this is because we sampled several villages containing the studied ethnic groups. Those villages represented a broad range of different ethnic responses (Fig. 1, Table 2). Furthermore, we also controlled for the characteristics of the villages our subjects lived in (Table 3). If we had only selected one Malinke and one Fulbe village for our experiment (e.g., Boubere and Beleya Koko), we would not have been able to control for village characteristics and would have estimated a highly significant effect of ethnicity on fairness. We would have concluded that Malinke are much more selfish than Fulbe (A24 in the ESM) and probably would have speculated about the reasons for this ethnic difference in behavior. This finding highlights the necessity of sampling a multitude of populations for each cultural group of interest and controlling for contextual factors when conducting cultural comparative studies (Lamba and Mace 2011; Oosterbeek et al. 2004).

It is obvious that the social structure of the villages (kinship, ethnic homogeneity, market integration, population size, income inequality) shaped the behavior of subjects (Fig. 3). More research is needed to uncover the underlying mechanisms that work on these variables. This is especially true for kinship and ethnic homogeneity. Whereas the behavior of subjects in our experiment was significantly influenced by kinship and ethnic homogeneity at the aggregate level (the average kinship and the homogeneity of the village), measures at the individual level (the proportion of subjects’ kin or ethnic group to the total population) did not influence the behavior of subjects in our experiment (Table 3). This finding is puzzling. Although the individual and the aggregate measures correlate strongly (A16), only the aggregate measures influence individual behavior. A similar pattern was found in a study by Putnam (2007):

Diversity does not produce “bad race relations” or ethnically-defined group hostility, our findings suggest. Rather, inhabitants of diverse communities tend to withdraw from collective life, to distrust their neighbours, regardless of the colour of their skin, to withdraw even from close friends, to expect the worst from their community and its leaders, to volunteer less, give less to charity and work on community projects less often, to register to vote less, to agitate for social reform more, but have less faith that they can actually make a difference, and to huddle unhappily in front of the television. Note that this pattern encompasses attitudes and behavior, bridging and bonding social capital, public and private connections. Diversity, at least in the short run, seems to bring out the turtle in all of us (2007:150–51, italics in original).

Finally, we were dealing in our study with traditional, small-scale societies that are partly in transition to more complex and socially stratified societies. The different villages showed substantial variations in population characteristics, and also the inhabitants of the villages differed in key characteristics, although they were all located in the same area (Fig. 1, Table 2). We were able to include a substantial part of this population in our experiment, allowing us to test some general hypotheses related to the biological drivers of human social behavior. We believe that our study population and design allows us to put our results in a broader human context. Some scholars have argued that humans are a unique species because our altruism is not primarily based on kinship. The evolution of fairness and cooperation in large-scale societies cannot be explained solely by genetic evolution and is best accounted for with cultural evolution and gene-culture coevolution. The empirical evidence for these claims is based to an important extent on behavioral experiments (Fehr and Fischbacher 2003; Gintis et al. 2003; Henrich et al. 2010). However, most of these experiments do not include measures of kinship in their analysis. In our experiment, we found a statistically significant effect of kinship on fair behavior. We also found significant effects for all other discussed mechanisms that favor fairness through natural selection. We are therefore inclined to conclude that evolutionary biology is a useful tool to analyze human social behavior and explains the behavior of subjects in our experiment. However, we are well aware that cultural evolution makes the same predictions related to the effect of population size (Forber and Smead 2014; Huck and Oechssler 1999), market integration (Hoel 1987; Roth and Erev 1993; Rubinstein 1982), and reputation (Chiang 2008) as biological evolution. Similarly, ethnic markers can be conceived of as biological, cultural, or both (McElreath et al. 2003), and even kinship has an important cultural dimension (Jones 2000). Moreover, economic game theory, which makes use of rationality and utility maximization assumptions, comes to similar conclusions as evolutionary game theory (Skyrms 1994, 2000). Culture and nature are closely intertwined in humans. More research must therefore be conducted to develop tools allowing to empirically tease apart their contributions to human social behavior in samples that are not made up of twins. Considering the relevance of experimental game theory in this domain of research, these tools should be compatible with a gametheoretical experimental approach.

Is War in Our Nature? What Is Right and What Is Wrong about the Seville Statement on Violence

Is War in Our Nature? What Is Right and What Is Wrong about the Seville Statement on Violence. Azar Gat. Human Nature, June 2019, Volume 30, Issue 2, pp 149–154. https://link.springer.com/article/10.1007/s12110-019-09342-8

Abstract: The Seville Statement on Violence rejected the view that violence and war were in any way rooted in human nature and proclaimed that they were merely a cultural artifact. This paper points out both the valid and invalid parts of the statement. It concludes that the potential for both war and peace is embedded in us. The human behavioral toolkit comprises a number of major tools, respectively geared for violent conflict, peaceful competition, or cooperation, depending on people’s assessment of what will serve them best in any given circumstance. Conflict is only one tool—the hammer—in our diverse behavioral toolkit. However, all three behavioral strategies are not purely learned cultural forms. This naive nature/nurture dichotomy overlooks the heavy and complex biological machinery that is necessary for the working of each of them and the interplay between them. They are all very close under our skin and readily activated because they have all been very handy during our long evolutionary past. At the same time, they are variably calibrated to particular conditions through social learning, which means that their relative use may fluctuate widely. Thus, state authority has tilted the menu of human choices in the direction of the peaceful options in the domestic arena, and changing economic, social, and political conditions may be generating a similar effect in the international arena.

Check also The phylogenetic roots of human lethal violence. José María Gómez et al. Nature volume 538, pages 233–237 (October 13 2016). https://www.bipartisanalliance.com/2018/02/the-phylogenetic-roots-of-human-lethal.html

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Seville Statement on Violence https://en.wikipedia.org/wiki/Seville_Statement_on_Violence
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[The Seville statement] was published during the heyday of Rousseauism, the view that the aboriginal human past, before the advent of agriculture and the state, was nonviolent and peaceful. This view dominated anthropology and culture in general during that time and was itself a reaction against earlier scholarly theories and popular books, such as those by Ardrey (1966), Lorenz (1966), and Morris (1967), which presented war as unique to humans, a primary drive rooted in human nature and erupting irresistibly. Thus, the statement rejected the view that violence and war were in any way rooted in human nature and proclaimed that they were merely a cultural artifact.

In the context of the reaction against Rousseauism, the Seville Statement has been criticized as an example of false-consciousness and the subordination of scholarly integrity to an ideological cause, noble as it may be (e.g., Beroldi 1994; Manson and Wrangham 1987; Pinker 1997). While this criticism is fully justified, I take this opportunity to point out both the valid and invalid parts of the statement. In doing so, I hope to clarify why people actually fight; whether fighting is in human nature, and in what sense; and, consequently, whether violence and war can be eliminated or, more realistically, drastically reduced. Because the biological underpinning of war and peace has been the subject of much confusion and a heated controversy—among neurobiologists, ethologists, anthropologists, psychologists, political scientists and others—it is in great need of clarification. And the root of the confusion is this: People habitually assume that if widespread deadly violence has always been with us, it must be a primary, “irresistible” biological drive that is nearly impossible to suppress. Many find in this conclusion sufficient reason to object to the idea that human fighting is as old as our species, whereas others regard it as compelling evidence that war is inevitable.2 However, both sides are wrong. Contrary to fashionable 1960s notions, traced back to Freud’s latter-day theorizing about a death drive or instinct, thanatos (Freud 1920, 1923, 1930, 1933a, b), violence is not a primary drive that requires release, like hunger or sex. The Swiss or Swedes, for example, who have not fought another country for two centuries, show no special signs of deprivation on this account. But try to deny them food for more than a few hours, or sex, say, for more than a few days, and see what will happen. [...]

On the other hand, the fact that violence is not a primary drive does not mean that we are not hardwired for it. Studies on “warless” pre-state societies usually intend to prove that warfare, being neither primordial nor natural to humankind, was probably a late, and in any case wholly contingent, cultural phenomenon. Margaret Mead’s framing of the problem: “Warfare Is Only an Invention – Not a Biological Necessity” (1940), is the mother of all mistakes. It expresses the widespread assumption that violence must be either a primary drive or entirely learned, whereas in reality, its potential is deeply ingrained in us as a means or tool, ever ready to be employed. People can cooperate, compete peacefully, or use violence to achieve their objectives, depending on what they believe will serve them best in any given circumstance. In cooperation, the parties combine efforts, in principle because the synergic outcome of their efforts divided among them promises greater benefit to each of them than their independent efforts might. In competition, each party strives to outdo the other in order to achieve a desired good by employing whatever means they have at their disposal except direct action against the other. Competition runs parallel. By contrast, in a conflict, direct action against the competitor is taken in order to eliminate it or lessen its ability to engage in the competition (Simmel 1955).

Cooperation, competition, and conflict are the three fundamental forms of social interaction (in addition to avoidance, or zero interaction). People have always had all three options to choose from, and they have always assessed the situation to decide which option, or combination of them, seemed the most promising. Indeed, hunter-gatherer societies have elaborate procedures of conflict resolution, especially within their groups, precisely because conflict, often violent, is an ever-present and often occurring threat. People are well equipped biologically for pursuing any of the above behavioral strategies, with conflict being only one tool, albeit a major one—the hammer—in our diverse behavioral toolkit. Furthermore, Homo sapiens is a social species, whose local and regional groups—universally and uniquely bound together by ties of both kinship and shared cultural codes, including language and customs— cooperate within themselves in a variety of group activities, including fighting. Group fighting is often pursued for the attainment of collective goods, above all hunting territory and other scarce sources of food, as well as reproduction opportunities.

Thus, neither a late invention nor a compulsive inevitability independent of conditions, group fighting is part of our evolution-shaped behavioral menu. It is in this sense that both war and peace are “in our genes,” which accounts for their widely fluctuating prevalence in different sociohistorical contexts. The Seville Statement rightly puts it, in rejection of the view that human biology makes violence and war inescapable: “There is nothing in our neurophysiology that compels us to react violently. . . . We conclude that biology does not condemn humanity to war.” However, the statement fell into the opposite fallacy, proclaiming that warfare “is a product of culture” and solemnly prescribing that “IT IS SCIENTIFICALLY INCORRECT [emphasis in the original] to say that war or any other violent behavior is genetically programmed into our human nature.” The statement carelessly concluded: “Violence is neither in our evolutionary legacy nor in our genes.” In reality, the potential for both war and peace is imbedded in us. Although activated interchangeably and conjointly in response to the overall environmental and sociocultural conditions, all three behavioral strategies—violent conflict, peaceful competition, and cooperation—are not purely learned cultural forms. This naive nature/nurture dichotomy overlooks the heavy and complex biological machinery that is necessary for the working of each of these behavioral strategies and the interplay between them. Certainly, these deep, evolution-shaped patterns are variably calibrated to particular conditions through social learning. However, the reason why they are all there, very close under our skin and readily activated, is that they were all very handy during our long evolutionary history. They all proved highly useful and advantageous, thereby becoming part and parcel of our biological equipment. A number of scholars who have dealt with the question in fact express the view that human societies have always been Janus-faced, interchangeably resorting to both peace and violent conflict. According to Walker (2001:590): “Everywhere we probe into the history of our species we find evidence of a similar pattern of behavior: People have always been capable of both kindness and extreme cruelty.” Burch (2005), documenting the Alaskan Eskimos’ highly belligerent record, also devotes one part of his book to their peaceful interactions. Robert Kelly (2013:158, 165) writes: “To summarize so far, it is not useful to ask whether hunter-gatherers (inclusive of egalitarian and nonegalitarian types) are peaceful or warlike: we find evidence for both among them.” He adds: “Aggression appears in many species, suggesting that it has a long evolutionary history. . . . It is part of our behavioral repertoire, and at times served us well.”

Boehm (2013:333) similarly rejects the view “that there should be an either-or choice between setting up friendly, cooperative relations with neighbors, as opposed to fighting with them.” Both took place, interchangeably, with the same and with different neighbors. Based on his survey of 49 simple hunter-gatherer societies, Boehm (2013:334, also 327, 333) writes: “The finding here is that intergroup conflict and external peacekeeping would both seem to have been prominent in human political life, back to at least 45,000 BP and probably earlier.” Boehm (2013:327) puts both sides of simple hunter-gatherer societies’ behavioral repertoire in a proper perspective: “59 percent of the . . . forager sample has enough lethal intergroup conflict for this to be reported in an ethnography.” He adds (2013:330): “With human foragers, negotiations of some type (including truces and peacemaking) are found in more than half of the . . . societies surveyed (59 percent). However . . . formal and effective peacemaking is reported only for a few of the 29 societies.” 3 Hunter-gatherers suffered far greater violent mortality rates than state societies not because they lacked well-established and partly successful patterns of conflict resolution. It is just that hunter-gatherers’ anarchic condition, the absence of effective coercive authority, limited the effectiveness of these patterns as compared to state societies. Wars have been fought for the attainment of the same objects of human desire that underlie the human motivational system in general—only by violent means, through the use of force. Here I take issue with Pinker’s excellent The Better Angels of Our Nature (2011), with whom I am otherwise in much agreement. “Angels” versus “Demons” in the human behavioral system is an allusion to Lincoln’s first inaugural address and is largely invoked metaphorically. And yet not entirely, because Pinker points to particular human quests such as dominance or ideology as “demons” with which the blame for war rests. Yet, dominance or ideology, no less than the desire for sex, can just as well be counted on the side of the “angels”—when pursued by peaceful means and for peaceful ends. For example, there have always been peaceful ideologies—such as Buddhism, and, in principle, though all too often not in practice, Christianity—which have exercised a considerable pacifying effect.

Furthermore, the distinctions that Pinker draws between different categories of violence respectively related to the above “demons” are also questionable. He cites studies showing that separate parts of the brain may trigger violent behavior, which is true of nearly all behaviors. But this does not mean that all violent behaviors are not subject to, and regulated by, a unified evolutionary calculus originally designed to advance survival and reproduction, the very definition of the evolutionary rationale which Pinker as an evolutionist would surely be the first to accept. The “problem” of war is not these or other human desires. Rather, violence and war occur when the conflictual behavioral strategy is judged to be more promising than peaceful competition and cooperation for achieving scarce objects of human desire. Both our basic desires and the conditions that channel the efforts to fulfil them to the conflictual path are necessary for understanding why war occurs. Thus, the advent of coercive state authority and state policing has tilted the menu of the human behavioral strategies in the direction of the peaceful options in the domestic arena, affecting a great reduction in the rate of killings—in the form of homicide and blood revenge—within societies. Moreover, changing economic, social, and political conditions have been generating a similar effect in the international arena, most notably where a modern liberal economic and political order prevails and peaceful behavioral options become that much more rewarding than the violent option in achieving unprecedented levels of affluence and comfort (Gat 2006, 2017; Goldstein 2011; Morris 2014; Pinker 2011). It is not that modern war has become more costly compared with earlier times, as many believe—it has not; it is peace that has become more rewarding (Gat 2006, 2017). Thus, countries with (non-oil) GDP per capita higher than $20,000 no longer fight each other, nor experience civil war. The most developed parts of the world, such as Western Europe and North America, have become a zone of peace. Within them war is not even contemplated, or feared—the famous “Security Dilemma” has disappeared—a situation which is unparalleled in history. [...]

From 2018... The Sordid Truth behind Degas’s Ballet Dancers

From 2018... The Sordid Truth behind Degas’s Ballet Dancers. Julia Fiore. Artsy, Oct 1 2018. https://www.artsy.net/article/artsy-editorial-sordid-truth-degass-ballet-dancers

Excerpts:

The coteries of young women in flowering tutus who populate the approximately 1,500 paintings, monotypes, and drawings Degas dedicated to the ballet are among the French artist’s most universally beloved artworks. At first glance, Degas has rendered the sort of pretty, innocent world one might associate with a 6-year-old’s first recital. These works actually speak to an insidious culture that would be shocking to contemporary audiences.

Although it enjoyed unprecedented popularity in Degas’s era, the ballet—and the figure of the ballerina—had suffered a demoralizing fate by the late 1800s. Performances had been reduced to tawdry interludes in operas, the spectacle serving as an enticing respite for concertgoers, who could ogle the dancers’ uncovered legs.

These relationships always involved an unbalanced power dynamic. Young female members of the corps de ballet entered the academy as children. Many of these ballerinas-in-training, derisively called “petits rats,” came from working-class or impoverished backgrounds. They often joined the ballet to support their families, working grueling, six-day weeks.

And so dancers’ earnings and careers were beholden to the abonnés prowling backstage. They were expected to submit to the affections of these subscribers, and were frequently encouraged by their own mothers to fan the flames of male desire. Such relationships could offer lifelines for the impoverished dancers; not only did these aristocrats and financiers hold powerful positions in society, their patronage underwrote the opera’s operations.

Men like these had authority over who obtained plum roles and who was cast off. As a girl’s “patron,” he could provide her with an opulent lifestyle, paying for a comfortable apartment or private lessons to elevate her standing in the ballet corps. The brothel culture of the ballet was so pervasive, as historian Lorraine Coons remarks in her essay “Artiste or coquette? Les petits rats of the Paris Opera ballet,” that even successful dancers who did not resort to prostitution would likely have been suspected to have done so anyway.

“People call me the painter of dancing girls,” Degas once explained to Parisian art dealer Ambroise Vollard. “It has never occurred to them that my chief interest in dancers lies in rendering movement and painting pretty clothes.” But Degas didn’t care tremendously about the ballet as an art form, let alone frilly pastel tutus. He endeavored to capture the reality of the ballet that lurked behind the artifice of the cool, carefully constructed choreography.

Life was cruel to French ballet dancers, and they didn’t have it much easier at the hands of Degas himself. Although the artist was known to reject the advances of his models, his callousness manifested in other ways. To capture the physicality and discipline of the dancers, Degas demanded his models pose for hours at a time, enduring excruciating discomfort as they held their contorted positions. He wanted to capture his “little monkey girls,” as he called them, “cracking their joints” at the barre. “I have perhaps too often considered woman as an animal,” he once told the painter Pierre Georges Jeanniot in a moment of revealing honesty.

Degas was undoubtedly a merciless, cantankerous man. He was a misogynist—peers seemed almost afraid of his antagonism towards women—an especially troubling reputation considering the already sexist norms of his society.

We investigate the impact of papal visits to Italian provinces on abortions from 1979 to 2012: Find a 10–20% decrease in abortions that commences in the 3rd month and persists until the 14th month

Papal visits and abortions: evidence from Italy. Egidio Farina, Vikram Pathania. Journal of Population Economics, December 31 2019. https://link.springer.com/article/10.1007/s00148-019-00759-0

Abstract: We investigate the impact of papal visits to Italian provinces on abortions from 1979 to 2012. Using administrative data, we find a 10–20% decrease in the number of abortions that commences in the 3rd month and persists until the 14th month after the visits. However, we find no significant change in the number of live births. A decline in unintended pregnancies best explains our results. Papal visits generate intense local media coverage, and likely make salient the Catholic Church’s stance against abortions. We show that papal visits lead to increased church attendance, and that the decline in abortions is greater when the Pope mentions abortion in his speeches.

Keywords: Abortion Religion Pope Culture Fertility

7 Discussion

To recap, we find a large and statistically significant decrease in abortions, ranging from − 10 to − 20%, that commences about 3 months after the papal visit and persists until the 14th month. We do not find any subsequent uptick in live births. The findings taken together suggest a strong indirect effect—papal visits induce a reduction in unintended pregnancies that starts around the time of the visits and persists for almost 1 year. In contrast, any direct effects of restriction in demand and/or supply of abortion appear to play limited role.

We have been agnostic whether the decrease in unintended pregnancies is being driven by increased abstinence or increased usage of contraceptives; we have bundled both behaviours as contraception. Despite extensive search, we were unable to locate extant Italian household survey data that would allow us to measure how papal visits affect the frequency of sexual intercourse or usage of contraceptives. But even if surveys were available, one would have to be careful in interpreting behavioural changes that would be the net effects of an increased desire for intended pregnancy among some women and also an increased aversion to unintended pregnancy among other women.21

In discussing the indirect effect, two other features of Church doctrine are relevant. First, the Church regards sexual intercourse as a sin if conducted outside sacramental marriage, or, even within wedlock, if deprived of its procreative function. Therefore, during and after papal visits, women might practise more abstinence unless they are planning on getting pregnant. Note that this is separate type of stigma that would independently drive down unintended pregnancies. Second, the Church explicitly discourages contraceptive usage because it breaks the connection between sex and reproduction within marriage and encourages recreational sex out of wedlock.22 For women seeking to minimise the risk of an unintended pregnancy, this poses a dilemma. One way out is to more abstinence. But some may opt for more usage of contraceptives as the “lesser of two evils”. Therefore, a mix of both behaviours—more abstinence and more contraceptive usage—may be driving the reduction in unintended pregnancies.

Thus far, we have assumed that all women have the chance to modify their behaviour in response to papal visits. But there is also a group of women who would have gotten pregnant before the papal visit became salient, and detected the (unintentional) pregnancy shortly before or after the visit. Faced with an increased cost of abortion, some women who would have chosen to abort might opt not to do so. We would then expect to see a contemporaneous drop in abortion, albeit smaller than the subsequent decline, and a spike in births 9 months later. But we find no such effects. It appears that, if already pregnant, papal visits do not change women’s abortion decisions. In other words, even the heightened cost of abortion is less than the cost of an unwanted birth. Looking back at the model in Section 4 (and Table 4), we can infer that among women who choose to abort, most are type II (always-aborters) and only a few are type III (switchers). Earlier, we had drawn the same inference from the lack of increase in births reported in Section 5.2. It is worth noting that the proportion of switchers is endogenous to the change in the cost of abortion; the greater the increase, the higher that proportion. The fact that switchers form only a small proportion suggests that the heightened stigma of abortion from papal visits is not sufficiently large to induce women to switch away from abortions, conditional on being pregnant.

Could our findings be driven by under-reporting?23 Stigma could drive women to switch to “back-street” abortion providers to keep the procedure secret. We cannot rule out under-reporting as a factor but it is unlikely to be the main explanation for our findings. With under-reporting, one would expect to see a drop in abortions contemporaneous with the papal visit.

How do our findings compare to those reported in the recent paper by Bassi and Rasul (2017) on the effect of the papal visit to Brazil in 1991? Their methodology is different from ours. For identification, they exploit the fortuitous timing of the 1991 DHS survey in Brazil which was fielded in the weeks before, during

and after the papal visit. They study how short-run beliefs and long-run behaviour of individuals respond to the papal persuasion. They report a substantial increase in the frequency of sexual intercourse, and a large reduction in the use of contraceptives among women interviewed post-visit. The net effect is a 26% increase in the frequency of unprotected sex that drives a positive fertility response with a spike in births 9 months post-visit. In contrast, in the Italian setting, we find no net effect on births. One plausible explanation for the difference is that a papal visit to Brazil is a much bigger event because it is so rare. This could have much larger effects on the perceived costs of abortion as well as on fertility preferences of Brazilian women.

As already noted, abortion ratios are highest among teenagers (see Table 2). We test how teen abortions respond to papal visits. The findings are reported in the Appendix A-Table 15. The effect on abortions is smaller for teenagers; there is a statistically significant decline of about 10% in the third quarter following the visit but no significant declines in other periods. We also test for the impact separately by age group, education level and marital status. The results are summarised in Appendix A, Figs. 9, 10 and 11. In general, the effects appear similar across groups except for a few differences. The decline appears to be larger for married women than for unmarried ones, and to a lesser degree, for less educated women versus higher educated ones. The finding of smaller effects for unmarried women is not surprising given what we find for teens, who likely make up a big part of the unmarried group. However, when we use pooled regressions to explicitly test whether the difference between married versus unmarried is statistically significant, we cannot reject the null of similar sized effects. The same is true for the difference by education level.

7.1 Is there a pattern to papal visits?

We ask whether papal visits are planned in response to underlying trends in abortions or religiosity. The concern is that if the Pope is more likely to visit provinces that are exhibiting a trend of relatively increasing religiosity (and concurrently a decreasing relative abortion rate), our estimate of the impact is not ‘causal’ but merely reflects this underlying trend.

First, we note that our identification strategy relies on the precise timing of the event, and in the preferred specifications, we control for province-specific quadratic time trends. Reassuringly, we find no discernible effect in the quarters (or months) preceding the event. Hence, we would argue that our estimates can be credibly inferred as causal.

Nevertheless, the time and place of a papal visit are unlikely to be random.24 The decision made by the Pope to visit a place could be driven by specific factors, e.g. motivated by the desire to reverse a general decline in religiosity among the local population that leads to an increasing abortion rate. If so, a papal visit may coincide with other (unobserved) ongoing activities by the Church in that province and during that time that could be driving our results.

We test whether the Pope is more likely to visit a province or region that exhibits an increase in the number of abortions or a decrease in the number of births or in the level of religiosity in the 1, 2 or 5 years preceding the papal event, using the following specification:

Pr(Pope Eventp,y=1)=α+β<percent>ΔiZp,y−1+γp×t+δp×t2+θp+θa+up,y$$Pr({\text{Pope Event}}_{p,y}=1)=\alpha +\beta <percent>{\Delta }_i{Z}_{p,y-1}+{\gamma }_p\times t+{\delta }_p\times t^2+{\theta }_p+{\theta }_a+u_{p,y}$$

(3)

where Pope Eventp,y is a binary indicator taking the value 1 if province p was visited by the Pope in year y; %ΔiZp,y− 1 represents the percentage change in the number of abortions, births or in the average religiosity indicator, as defined in Section 6.3, over the 1, 2 or 5 years preceding the visit of the Pope in province p, γp × t and δp × t2 are provincial yearly trends; 𝜃p and 𝜃y are province and year fixed effects.25

Table 10 displays the results from estimating Eq. 3. Starting from panel A, the papal visits do not respond to any pre-trend in the number of abortions registered in the 1, 2 or 5 years preceding the visit to a specific province. We repeat the same exercise to test whether the papal visits are influenced by changes in births (panel B) or religiosity (panel C). Also, in these cases, no statistically significant effect is detected. Overall, the results bolster confidence that our main findings are causal effects of papal visits and not merely picking up underlying trends in local religiosity and Church activities.

Behavioral correlates in twin studies: There was a moderate genetic influence on subjective sleep quality and sleep duration

Twin studies of subjective sleep quality and sleep duration, and their behavioral correlates: Systematic review and meta-analysis of heritability estimates. Juan J Madrid-Valero et al. Neuroscience & Biobehavioral Reviews, December 30 2019. https://doi.org/10.1016/j.neubiorev.2019.12.028

Highlights
• There was a moderate genetic influence on subjective sleep quality and sleep duration.
• There was substantial heterogeneity across studies.
• Heritability did not differ by geographical zone.
• Age and sex were not significant moderators of the heritability of subjective sleep quality or sleep duration.
• Genetic factors played a role in the associations between sleep variables and other factors.

Abstract: Twin studies have shown that a substantial proportion of the variance for sleep variables is due to genetic factors. However, there is still considerable heterogeneity among research reports. Our main objectives were to: 1) Review the twin literature regarding sleep quality and duration, as well as their behavioural correlates; 2) Estimate the mean heritability of subjective sleep quality and sleep duration; 3) Assess heterogeneity among studies on these topics; and 4) Search for moderator variables. Two parallel meta-analyses were carried out for sleep quality and sleep duration. Seventeen articles were included in the meta-analysis. Mean MZ correlations were consistently higher than DZ correlations. A mean heritability of 0.31 (95% CI: 0.20, 0.41) was found for subjective sleep quality (range: 0-0.43) and 0.38 (95% CI: 0.16, 0.56) for sleep duration (range: 0-1). Heterogeneity indexes were significant for both sleep quality (I2 = 98.77, p < .001) and sleep duration (I2 = 99.73, p < .001). The high heterogeneity warrants further research considering possible moderators that may affect heritability.

Keywords: HeritabilityMeta-AnalysisTwinSleep qualitySleep duration