Thursday, March 7, 2019

Although we are undoubtedly omnivores, we evolved quite early to become highly carnivorous and we continue to retain a biologic adaptation to carnivory

Ben-Dor, Miki (2019) "How carnivorous are we? The implication for protein consumption," Journal of Evolution and Health: Vol. 3: Iss. 1, Article 10. https://doi.org/10.15310/2334-3591.1096

Full text, references, etc., in the link above.

Introduction
The Paleo Diet evolutionary mismatch principle suggests that the closer we stay to the diet that we evolved to consume the better chances we have to stay healthy. There is little doubt that meat was a significant component of the Paleolithic diet and that it was acquired largely by hunting [1] and thus Paleolithic humans can be defined as carnivores.The definition of carnivory, however, is vague as a dietary pattern. There are 'carnivores' belonging to the Carnivora familythat doesn't eat meat (Panda bears).There are 'obligate carnivores' that rely on very high protein consumption (cats).There arehypercarnivoresthat by definition consume more than 70% of the calories from animal sources and there are even 'epic carnivores 'at the very top of the food chain (lions). The purpose of the present investigation is not to assign humans to any of these categories but to find out whether during our evolution we became adapted to consume large quantities of meat on account ofaprevious adaptation to consume large quantities of plants. If so, we can assume that a relativelylarge quantityof meat will be safer than consuming a relativelylarge quantityofplant foods. Another question that comes up is to what level of protein consumption we became adapted. Since in diet, every item that we consume replaces anitem that we could consume, if we are adapted to consume animal sourced protein, we can consider it to be a safer food than other foods, like domesticated plants, In this context, the question of the evolutionary level ofprotein consumption during the Paleolithic has never received adequate attention. Since there is relatively little protein in plants, the answer is derivedfrom the relative amount of animal food in the human diet.If animal food consumption wererelatively high during the Paleolithic,then relative protein consumption would have also been high.Quite a few authors tried to estimate the caloric Plant:Animal ratio (DPA) in the humans ’Paleolithic diet [2-8]. A wide variation of DPA’s was predictedwith averages ranging between 66% plants and 33% animal[4] to 35% plantsand 65% animal[2]. Alas, because in the archaeological record plants preserve poorlyor not at all, all of the estimatesrelied to a great extenton the ethnographic record of diets of recent hunter-gatherers' (HG) groups with a tacit or expressed claim for the analogybetween the periods. However, I claim that the HG's ethnographic record 1 should not be used to predict Paleolithic diets, or indeed even variability in the diet, as the ecologies of the two periods are so different as to denyany scientific validity to such prediction. Here I outline a short review of the relevant ecological conditions in support of my claim. A full paper is in preparation. Recent hunter-gatherers ethnography is a misleadingsource of Paleolithic diet reconstructionIn discussing the use ofethnographicsourced analogies in archaeology, Ascher (9)summarized his contemporaries, Clack, Willey, and Childes’ opinions thus: “...the cannon is: seek analogies in cultures which manipulates similar environments in similar ways.” In other words, the degree of similarity between the ecological and technological conditions of the known and unknown periods is the key criteria in judging the validity of ethnographic sourced analogies. A review of the recent ecological conditions revealsthat especially in one crucialaspect, availabilityand size offaunal and floral resources, there is a drastic and unbridgeablegap between the Paleolithic and the recent modern HG period. In a recent paper, Smith et al. [10] calculated the mean body weight of non-volant (not flying) terrestrial mammals during the last 2.5 million years. A drastic decline in terrestrialmammals took place from approximately 500 kgs at the beginning of the Pleistocene 2.5 million years ago to about 10kgs today. In the same vein, Bibi et al.[11] compared the faunal assemblagesof Olduvai Middle Bed II at 1.7-1.4 million years ago (Mya) to faunal communitiesin the present day Serengeti. They concluded that “The sheer diversity of species, including many large-bodied species, at Neogene and Pleistocene African sites like Olduvai, is perplexing and makes extant African faunas look depauperate in comparison.”Indeed, they present a hypothesis, supported by reduced carnivore richness in the Early Pleistocene [12], that human predation may have been the cause of the loss of largeherbivores during the Pleistocene. A significant part of the reduction occurred in the Late Pleistocene and is a global phenomenon.During the Late Quaternary Megafauna Extinction,about 90 genera of animals weighing >44 kg became extinct beginning some 50 Kya [13]. The rate of extinctionby body size follows a typical pattern in which the largest size genera became more completely extinct. In all the continents, apart from Africa and the Indian sub-continent, all genera exceeding 1000kg became completelyextinct, and those in the 1000-320 kg category became 50-100% extinct. In Africa, Some 25% of what was left in the Late Quaternary’s megafauna (>45 kg) became extinct [14].

In Africa, however, even the few large animals that remained were hardly available for hunting by HG groups that form the basis for many analogies with the Paleolithic, the Hadza, and the San. Elephants were huntedby Europeans with guns in the Hadza and San’s territories for over a hundred years. There is evidence for a drastic decline in the availability of animals as a result of herders and farmers encroachment abound [15, 16].The result is that the Hadza no longer hunt the three largest animals in Africa, elephants, rhinos, and hippos. Moreover, the disappearance of large animals, and especially elephants, caused a substantial increase in the availability of plant food sources. Elephants are known to be a formidable predator of baobab trees[17]. Baobab isthe single largest contributor of calories to the Hadza as well as a homefor theirmost popular species of honey bees.A similar phenomenon occursin the San (!Kung) territory where the mongongo tree, their staple food source, was subject to partial destruction and growth retardation when elephants were present in its vicinity [18:312]. In summary, the differences in the relative availability of plants and animals and especially big animals, between the Paleolithic and modern HG'speriod are so criticalthat they prevent any inferencefrom the recent HG DPA to Paleolithic DPA, including any conclusion regarding the degree of DPA variability during the Paleolithic. So, if ethnography and archaeologyare poor sources for DPA estimates, are there other fields of knowledge we can explore? As it turns out, physiology can be a trove of information for evolutionary DPA, as adaptations to one DPA or another are stored in our body in the forms of genetics, morphology,metabolism,andsensitivity to pathogens. Reconstruction of the Paleolithic diet based on human physiologyA more detailed reconstructionwhich was performed as a part of my Ph.D. thesis and is in preparation for publication. What follows is a short review of some of the physiological adaptations or lack thereof that provide evidence for the nature of our past diet. The first three adaptations are unique in that the authors themselves point out (maybe to their surprise) that according to their finds, we have various physiological processes that align with that of carnivores.

Weaning like a carnivore
Life history, the age at which animal reach certain stages in life like gestation, weaning, mating, and death,is strongly defined in a species. Psouni et al. [19]found that adult brain mass, limb biometrics,anddietary profile can explain 89.2% of the total variance in time to weaning. Comparing 67 species, they found humans to be in the carnivores’ group while chimpanzees and other primates with the non-carnivore's group. They conclude: "Our findings highlight the emergence of carnivory as a process fundamentally determining human evolution."Many smaller fat cellslike all carnivoresPond and Mattacks (20) compared the structure of fat cells in various types of animals. Carnivores were found to have a higher number of smaller fat cells and omnivores a smaller number of larger fat cells. Humans were found to beat the top of the carnivorous pattern. Pond and Mattacks conclude: “These figures suggest that the energy metabolism of humans is adaptedto a diet in which lipids and proteins rather than carbohydrates, make a major contribution to the energy supply.”

Stomach acidity of a unique carnivore
Beasley, Koltz (21)emphasize the role of stomach acidity in protection against pathogens. The found that carnivores’ stomachs at a pH of 2.2 are more acidic than omnivores’stomachs at a pH of 2.9 but less acidic than obligate scavengers at pH of 1.3. According to Beasley, Koltz (21) Humans had a high level of acidity of 1.5 that lies between that of obligate and facultative scavengers. Producing acidity,and retaining the stomach walls to contain that acidity,is energetically expensive, so would presumably only evolve if the level of pathogens in the human diet was high. The authors surmise that humans were more of a scavenger than we thought. However, there is a more likely conclusion if we take into account that humans were a particular kind of carnivore. Unlike other carnivores, they consumed the meat over several days either in a central place (home base) [22] or, for very large animals,where it was acquired [23]. Big animals, like elephants and bison, and even smaller animals like zebra, provide enough calories to last a 25-member HG group for days and weeks [24]. During this time the pathogen load is bound tobuildup to a higher level than even a regular scavenger encounters under normal circumstances and hence the presumed need for high acidity.

Reduced energy extraction capacity from plants.
Most plant eaters extract a large part of their energy from the fermentationof fiber by gut bacteria[25]. In primates,the fermentation takes place in the large intestine.For example, a gorillaextractssome 60% of its energyfrom fiber[26]. The fruits that chimps are consuming are also very fibrous [27].Their large intestines form 4
52% of the volume of the gut, similar to the 53% in the gorilla [28], indicating that,like a gorilla,they also drive a similarly highportion of their energy from fiber.An adaptation that preventshumans from efficientexploitation of fiber to energymay point to a shift in the dietary emphasisaway from plantstowards specialization in animal’s sourced food [See 29 considering criteria for specialization]. Our gut is 40% smaller[30], and one can therefore calculate that our large intestine, where fiber is processedto energy, is 77% smallerby volume than that of a chimpanzee our size[28]. The size and our small intestine, where -macronutrients are absorbed is 62% larger than that of a chimpanzee our size. Since the Chimpanzee was able to absorb a large amount of sugar with a shorter small intestine, The 66% extension could representan adaptation to consuming more fat and proteinin humans. Since the masticationsystem prepare the food for the gutareduced mastication system already1.7 million years ago (Mya) in H. erectussuggests that the gut size of H. erectuswas already reduced [31].We can thus propose that H. erectusspecialed in non-plant food items.The omnivorous pigs are sometimes mentionedas a good model for human nutrition [32], however,the volume of their large intestine is higher than the volume of their small intestine [32]the reserveratio in humans[28], pointing to the adaptationof pigs to highly fibrous food.The changed gut composition meets the criteria for specialization proposed by Wood and Strait (29). They propose that adaptation towards specialization is marked by a change that enables the acquisition of one resource while interrupting in the acquisition of another resource.In our case,the gut morphology adaptations both improvedanimal food exploitationand at the same time hindered the full exploitation of fibrous plant foods.Endurance running Bramble and Lieberman [33] list 22 specific adaptations to endurance running and claim they represent an adaptationto ‘persistence hunting’. There is some disagreement as to the significance of the 'persistence hunting' technique[34],butas it representsan adaptationto better mobility, it may also indicate adaptationto operating in a largerhome-range. Carnivores with a large proportion of flesh in their diets such as Canids and Felids have particularly large home-ranges whereas omnivorous carnivores like Ursidae have a narrower home-range[35].Adaptation to aspear throwingRoach et al. [36]claim that the structure of our shoulderrepresents an adaptation to carnivory. They describe howour shoulder is perfectly adaptedto throwing, which must be useful, in their opinion, mainly in hunting and protection from predators. They show that in contrast, thechimpanzee’s shoulder is adaptedto climbing trees.

This evidence may serve as another evidence for specialization in carnivory, like the smaller gut,the improved ability toobtain animal food comes at the account of reduced ability to obtain plant-sourcedfood, fruits in this case.High-fatreservesHumans have much higher fat reserves than chimps,our closest relatives [37]. Carrying a high amount of fat cost energy and reduce the speed of chasing or fleeting[38]. Most carnivores and fleeting herbivores do not pack much fatas, unlike humans, they rely on speed for predation or evasion.Recent HG were found to have enough fat reserves to fast for three weeks for men and six weeks for women[39]. This ability may represent anadaptation that is unique to carnivory of large animals by a predator who does not rely on speed. The large fat reserves may have allowed human tobridgelonger periods between less frequent hunts of largeranimalsdue to their relativelylower abundance.

The AMY1 gene -Incomplete adaptation to metabolize starch?
Humans have a varying number of AMY1 gene copies (2-12 copies [40]) which synthesize salivary amylase whereas chimpanzees have only two copies.The higher copy number may represent different degrees of adaptation to consuming starch[40] although the results of actual health markers associations with the number of copiesare equivocal [41-47].Herbivores and carnivores donotseem to have salivary amylase (although the data are limited) whereas omnivores usually produce high quantities of the enzyme [48]. This variancein the number of copies in humans in itself can be(but doesn't have to be)a testimony that the adaptationis relatively recent and have not beenfixedyet. However, until better grasp is obtainedon the timing of the change in copy number, little can be said about its significance to the question of DPA in humans.Recent genetic adaptation to tuber consumptionTubers, which are available year-round and are as energy dense as wild fruits,are mentionedas a good candidate for Paleolithic plant-based diet [49]. Populations that presently depend on tubersare enrichedin genes that are associatedwith starch metabolism, folic acid synthesis,andglycosides neutralization, but other populationsare not[50]. These adaptations presumably compensate for these tubers’ poor folic acid and relatively high contentof glycosides. The very limitedgeographicdistribution of these genes[50]maymeanthat their presence in humansis quite recentso that tubers did not form an importantpart of the human Paleolithic diet.

The earliestevidence for caries -15,000 years ago
High consumption of starch and sugars is associatedwith the development of oral cariescavities [51].Frequenciesof carious lesions in archaeological populations rangefrom 2.2–48.1% of teeth for agricultural populations, but only0–14.3% for hunter-gatherers[52]. A high prevalence of cariesfirstappearedsome 15.0 Kya in a site in Morocco, together with evidence for exploitation of starchy foods[53]. Thisrecent phenomenon may mean that high carbohydrates (plants)consumption is a relatively recentend-of-Pleistocenephenomenon.It should be pointedout that in some more recent traditional societies high starch consumption was not associated with a highprevalence of caries [54].

Paleolithic dietary reconstruction based on human Physiology –conclusion
Although physiology is only one of the sourcesfor Paleolithic dietary reconstruction, looking into the information that is storedin our bodyprovide an interesting and sometimes new evidence that we underwent substantial adaptation towards carnivory and that it started quite early in our evolution as the genus Homo. It also supports the notion thatwe remain adapted to carnivory despite over 10,000 years of agricultural subsistence. Consequently, it seems, in reply to the question at the heart of this paper,that we are adaptedto consume high quantities of protein. How high? The answer lies in reconstructing our behavior during prehistory regardingfat [24, 55].What was the protein consumption level during human evolution? The question of the desirable level of dietary protein consumption comes up in the literature and among professional and lay people who are interested in nutrition. This section tries to answer that question by discerning the Paleolithic level of consumption, assuming that it is a safelevel, following the evolutionary mismatch theory of chronic disease[56]. Protein processing for energy in humans is estimated to be physiologically limited to 35-45% of the daily calories[57, 58].If humans were at the protein limitduring the Paleolithic era, the remaining 55-65% of the calories should have come either from fat or carbohydrates, namely plants.There is ample ethnographic evidence for human dependence on and preference for animal fat as afood source. Kelly [59]writesin his authoritative book on HG: “...although ethnographic accounts abound with references to theimportance of meat they equally convey the importance of fat...”. He adds: “It, therefore,may be fatrather than protein that drives the desire for meat in many foraging societies”.

Lee [16] writes about the !Kung of the K alahari: “Fat animals are keenly desired, and all !Kungexpressa constant craving for animal fat”. The essentiality of fat is best demonstrated in Tindale’s account of the Pitjandjara of Australia[60]. He writes: "Whenkilling the animal they immediately feel the body for evidence of the presence of caul fat. If the animal is 'njuka',fatless, it is usually left unless they are themselves starving”. Coote and Shelton [61]report a similar behavioramong the Yolngu of Arnhem, Australia, saying that "Animals without fat may indeed be rejected as food".The importance of fat is also evident initsuse as a symboloffertility, sacredness, wealth, health and even life itself in recent traditional societies' rituals, linguistics and mythology [55]The archaeological record similarly showsthat many of humans’ particular acquisition and food exploitation behaviors can be interpreted as stemming from the need to obtain fat. Behaviors like the hunting of fatter animal or processing of fat from body parts at greater energetic expenditure thanwould have otherwise been needed indicate a concentration on fat as the primarycriterion in prey selectionand butchering. The preference of hunting larger animals and prime adultanimals within prey species[24, 62, 63], the preferenceto bring fatty parts to a central place and the extraction of bone grease [64],at great energetic costs,all point to a strategy of fat maximization. Thisenergetically expensive set of behaviors also supports the conclusion that plants could not provide a sufficient contribution to complement the protein at the limit of its consumption.This energetically expensive behavior is difficult to explain unless we assume that humans were at the limit of their protein consumption. Therefore, the implication for protein consumption from this reconstruction is that throughout our evolution as humans we obtaineda high portion of our calories from protein. Although no clear official statement of the upper limit on the consumption of protein has ever been published, there are reports of consumption of over 40% of the daily calories,or about 4 grams per kg body weight per day (g/kg/d) by circumpolar groups [65]. Rudman, Difulco (66)found the limit on urea removal to be 3.8 g/kg/dof protein to which the demand of structural protein at a minimum of 0.8grams per kg per day should be added [57]to a total of 4.6 g/kg/d. The present level of protein intake in the U.S.is some15.7% [67]of the daily calories. Based on consumption of 2000 calories for a 60 kgs person the currentconsumption is 314 calories whereas the Paleolithic level of consumption, according to this analysis was in the vicinity of 800 calories (40% of 2000) and possibly even higher at 1100 calories (4.6 g/kg/d X60 kgs X 4 cal/g).

Conclusion
As mentioned, this paper is just a part of a wider review, in preparation, of scientific evidence for the human evolutionary diet. Although we are undoubtedly omnivores, the biologic evidence that was presentedhere claims to show that we evolved, quite early in our evolution as the genus Homo, to becomehighly carnivorousand that we continue toretain abiologic adaptation to carnivory. This high level of carnivorymeans that during a largepart of our evolution our diet was high in protein besides being high in fat. If we look at the Paleo nutrition templateas a safety templet,this paper concludesthat it seems to be safe to consume a highportion of the diet from animal protein, possiblyto the tune of 30-40% of the daily calories. Since every calorie of protein that we do not consume is a calorie that will be consumed from another food source, the Paleo template guides us to consider the relative safety of alternatives to proteinwhen deciding on the actual level of protein consumption. Not many alternatives foods can claim to have nearly two million years of safe consumption.


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Wednesday, March 6, 2019

Why thinking over & over about something leads to ever more thoughts about it: Future voluntary imagery can be decoded from activity patterns in the brain up to 11 secs before engaging in voluntary imagery

Decoding the contents and strength of imagery before volitional engagement. Roger Koenig-Robert & Joel Pearson. Scientific Reports, volume 9, Article number: 3504 (2019). https://www.nature.com/articles/s41598-019-39813-y

Abstract: Is it possible to predict the freely chosen content of voluntary imagery from prior neural signals? Here we show that the content and strength of future voluntary imagery can be decoded from activity patterns in visual and frontal areas well before participants engage in voluntary imagery. Participants freely chose which of two images to imagine. Using functional magnetic resonance (fMRI) and multi-voxel pattern analysis, we decoded imagery content as far as 11 seconds before the voluntary decision, in visual, frontal and subcortical areas. Decoding in visual areas in addition to perception-imagery generalization suggested that predictive patterns correspond to visual representations. Importantly, activity patterns in the primary visual cortex (V1) from before the decision, predicted future imagery vividness. Our results suggest that the contents and strength of mental imagery are influenced by sensory-like neural representations that emerge spontaneously before volition.



Introduction

A large amount of psychology and, more recently, neuroscience has been dedicated to examining the origins, dynamics and categories of thoughts1,2,3. Sometimes, thoughts feel spontaneous and even surprising; while other times they feel effortful, controlled and goal oriented. When we decide to think about something, how much of that thought is biased by pre-existent neural activity? Mental imagery, a sensory thought, can be triggered voluntarily or involuntarily4. However, how much of the content and strength of our mental images we actually control when we voluntarily generate imagery remains unknown. For example, individuals with post-traumatic stress disorder (PTSD) report a complete lack of control of both the content and strength of their mental imagery5. While evidence suggests that imagery strength varies both between and within individuals in the normal population5,6. Previous research has shown that prefrontal activity can predict future decisions7,8,9,10, and nonconscious sensory activity11, and that mental images can be decoded from early visual cortex12,13. However, it remains unknown whether nonconscious sensory activity influences what we think and how strongly we think it.
To investigate the origins of the content and strength of voluntary imagery, we crafted a thought-based mental imagery decision task, in which individuals could freely decide what to imagine, while we recorded brain activation using functional magnetic resonance imaging (fMRI). We used multi-voxel pattern analysis (MVPA, see Materials and Methods for details) to decode information contained in spatial patterns of brain activation recorded using fMRI14,15,16. Additionally, in an independent control experiment, we estimated the temporal reliability of the reported onset of thoughts, as it has been criticized in previous paradigms17. Using a design exploiting the known effect of imagery priming on subsequent binocular rivalry as a function of time18, we show that participants’ reports of thought onsets were indeed reliable within the temporal resolution of fMRI.
Models of determinants of decision making postulate that executive areas in the prefrontal cortex would trigger selection processes leading to future choices9,10,19. In addition to the executive areas involvement in future visual thoughts, we aimed to test whether predictive information could also be decoded from visual areas, as previous results have shown that visual imagery recruits visual areas12,13. To test this, we used both searchlight and visual (from V1 to V4) regions-of-interest (ROI) decoding. We also sought to determine the representational content of the predictive signals: is predictive information, to some extent, similar to perceptual visual representations? To assess this, we perceptually presented gratings outside of attention to participants in separate runs. Functional brain images from the perceptual blocks were then used to train classifiers, which were subsequently tested on imagery blocks both before and after the decision. This so called perception-imagery generalization cross decoding was thus used to show common informational content between visual perceptual representations and predictive signals. Finally, we tested whether the subjective strength of visual imagery could be decoded from information in visual areas before reported volition. Such an involvement of visual areas in the future strength of visual imagery would provide further evidence that sensory areas also play an important role in the phenomenology of future thoughts.
Using this paradigm, we found that activity patterns were predictive of mental imagery content as far back as 11 seconds before the voluntary decision of what to imagine –in visual, frontal and subcortical areas. Importantly, predictive patterns in the primary visual cortex (V1) and the lateral prefrontal cortex were similar to perceptual representations elicited by unattended images. We show that the subjective strength (vividness) of future mental imagery can be predicted from activation patterns contained in the primary visual cortex (V1) before a decision is made. Our results suggest that the contents and strength of mental imagery are influenced by sensory-like neural representations that emerge spontaneously before volition. These results are important as they point to a role of visual areas in the pre-volitional processes leading to visual thought production, thus shedding light on the mechanisms of intrusive mental imagery in conditions such as PTSD, as well as the origins of normal mental imagery.

Concluding remarks and future directions

Our current study can be seen as the first to capture the possible origins and contents of involuntary thoughts and how they progress into or bias subsequent voluntary imagery. This is compatible with the finding that the most prominent differences between low and high vividness trials are seen for the pre-imagery period in visual areas, especially the primary visual cortex, which can be interpreted as when one of the patterns is more strongly represented it will induce a more vivid subsequent volitional mental image. This is in line with reports showing that imagery vividness depends on the relative overlap of the patterns of activation elicited by visual perception and imagery45. Our results expand that finding by showing that the vividness of future visual thoughts is predicted by information stored in the primary visual cortex.
It is up to future research to reveal whether representations biasing subsequent voluntary imagery are genuinely non-conscious or not. This will not only shed light on age-old questions of volition, but also provide a clear mechanism for pathological intrusive thoughts common across multiple mental disorders.

Evidence of a pure collaboration effect, distinct from motivations of future reciprocity, in-group favouritism or concern for accountability

Experimental evidence for a pure collaboration effect. Mary C. McGrath & Alan S. Gerber. Nature Human Behaviour (2019), Feb 18 2019, https://www.nature.com/articles/s41562-019-0530-9

Abstract: What makes us willing to sacrifice our own self-interest for another person? Humans can forgo short-term individual gain to achieve long-term benefits1,2,3,4—but long-run self-interest cannot fully explain unselfish behaviour5. Collaboration in our evolutionary past may have played a role in shaping an innate human sense of distributive justice6, influencing who we consider deserving of our aid or generosity. Previous research has not been able to isolate this response to collaboration as an independent effect, distinct from other motivations to share7,8. Here we present evidence of a pure collaboration effect, distinct from motivations of future reciprocity, in-group favouritism or concern for accountability. We demonstrate this effect among adult subjects in an economic setting, showing that the effect constitutes a psychological phenomenon with relevance for real-world social and political behaviour. This collaboration effect is substantial: it motivates sharing among people otherwise inclined to share nothing and increases the proportion of participants willing to give up half of their allotted money. We find evidence supporting our hypothesis that the collaboration effect operates by creating a sense of debt owed to one’s collaborator.

Men significantly donated money or other items to panhandlers more often while in the presence of a woman, using this display of generosity and wealth to signal positive attributes to potential mates

Distribution of Resources to Panhandlers as a Male Display of Potential Mate Quality. Amy Webb & Maryanne L. Fisher. Human Ethology Bulletin, Volume 33, No 4, 28-36,  Dec 31, 2018. DOI:  https://doi.org/10.22330/heb/332/028-036

ABSTRACT: Evolutionary psychological theory predicts that because women generally prefer men with resources, men will display their generosity and wealth in order to gain positive attention from potential mates. Therefore, the goal of the current study was to examine men’s displays of generosity and wealth in the presence versus absence of women. We hypothesized that men would donate money or other items most often in the presence of women, compared to while walking alone or in the presence of other men. We performed observations along busy pedestrian streets in Atlantic Canada, and documented the frequency with which men stopped to provide money or items to those begging (“panhandling”) for resources. Our results supported our hypothesis, as men significantly donated money or other items more often while walking in the presence of a woman, as compared to any other condition. We propose that men are using this display of generosity and wealth to signal positive attributes to potential mates. This finding offers a new avenue in which to test theories regarding mate preferences in a natural setting.

Keywords: Mate preferences, Resources, Ethology, Mate quality, Observation.


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Human Ethology Bulletin 33(2018)4: 28-36
Research Article
DISTRIBUTION OF RESOURCES TO PANHANDLERS AS A
MALE DISPLAY OF POTENTIAL MATE QUALITY
Amy Webb1 & Maryanne L. Fisher2
1Human Sexuality Research Laboratory, School of Psychology, University of Ottawa, Canada
2Department of Psychology, Saint Mary’s University, Halifax, Canada
awebb069@uottawa.ca
ABSTRACT
Evolutionary psychological theory predicts that because women generally prefer men with
resources, men will display their generosity and wealth in order to gain positive attention from
potential mates. Therefore, the goal of the current study was to examine men’s displays of
generosity and wealth in the presence versus absence of women. We hypothesized that men
would donate money or other items most often in the presence of women, compared to while
walking alone or in the presence of other men. We performed observations along busy
pedestrian streets in Atlantic Canada, and documented the frequency with which men stopped
to provide money or items to those begging (“panhandling”) for resources. Our results
supported our hypothesis, as men significantly donated money or other items more often while
walking in the presence of a woman, as compared to any other condition. We propose that men
are using this display of generosity and wealth to signal positive attributes to potential mates.
This finding offers a new avenue in which to test theories regarding mate preferences in a
natural setting.
Keywords: Mate preferences, Resources, Ethology, Mate quality, Observation.
__________________________________________________________
Webb, A. & Fisher, M.L.: Distribution of Resources
Human Ethology Bulletin 33(2018)4: 28-36
INTRODUCTION
Sex differences in theories surrounding mate preferences indicate that women generally
prefer men with resources. One explanation for this preference stems from parental
investment theory. The evolution of anisogamy (i.e., sexual reproduction with unequal
size of gametes) leads to the possibility that women are the more investing sex because of
disproportionate costs related to their gametes, gestation, and postpartum childcare
(Trivers, 1972; but see also Fisher, Garcia, & Burch, in press, for a review of criticisms).
While men’s reproductive success is thought to be largely determined by their number of
copulations, women’s reproductive success relies on their investments of time and energy
during conception, gestation, and post-partum childcare (Campbell, 1999; Trivers,
1972). Women’s substantial parental investment causes them to have a deficit in securing
adequate resources for themselves and/or their children, leading them to theoretically
rely on men’s resources and efforts to aid with children. Past research indicates women
are typically much choosier than men when selecting a mate (e.g., Walters & Crawford,
1994), and overall, express a preference for men who can provide care, have the ability
and willingness to invest resources, and contribute support for both them and their
children (e.g., Buss 1989; Lu, Zhu, & Chang, 2015).
Sexual selection theory (Darwin, 1871) leads to the premise that to experience
reproductive success, individuals need to out perform potential rivals for mates while
also appearing the most appealing to members of the opposite sex. Therefore,
individuals may endeavor to appear the best, compared to others of the same sex, in the
hopes that they are selected for mating. The traits that lead to this evaluation by potential
mates are the same as those involved in mating competition (Andersson, 1994), which
leads to difficulties in trying to tease apart whether an individual is displaying a preferred
mating-relevant characteristic to court a potential mate or to win against rivals, or both.
Recent developments indicate that for men, intrasexual competition more than women’s
mate preferences seem to have a larger role in shaping physical dominance (Kordsmeyer,
Hunt, Puts, Ostner, & Penke, 2018). Either way, these individuals who are high on these
preferred traits have evolved a reproductive advantage (Buss & Schmitt, 1993).
Men significantly vary in the specific qualities that women find appealing,
particularly when being considered as a prospective long-term mate (Buss & Schmitt, in
press). In a long-term mating situation, men are more likely to provide food, find or
defend territories, feed and protect children, and perhaps provide opportunities for
status transfer, power, or other resources (Buss, 1989; Buss & Schmitt, 1993). Women
consider a number of observable cues to judge whether a man is a desirable long-term
mate (Buss & Schmitt, 1993). One of the most important signals of his mate quality is
his ability to distribute resources, or whether he possesses traits that indicate future
accrual of resources, such as ambition, industriousness, and being a hard worker (e.g.,
Buss, 1989).
Ultimately, women generally benefit if they are able to identify potential mates who
are both willing and able to invest resources to them and their children, given the
potential deficits they will face in accruing independent resources. It is highly important
for women to observe such cues as ambition, industry, income, status, and generosity, as
these characteristics are correlated with a man’s ability and willingness to invest (Buss &
Schmitt, 1993). Thus, the current study is an examination of whether men display
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Human Ethology Bulletin 33(2018)4: 28-36
generosity and wealth via sharing their resources while in the presence of women, if
given the opportunity.
We observed men’s interactions with individuals asking for money (hereon called
panhandlers). Panhandlers are people who publicly request money, food, or other
donations from people they do not know (Lee & Farrell, 2003), and most are not
homeless (Dordick et al., 2017). They exist universally, and have likely existed across all
of time (Verma, Bharti, & Singh, 2018). Across a range of locations (e.g., Brussels,
Toronto, Moscow, Shanghai, and London), panhandlers typically earn an average hourly
income comparable to minimum wage in that location (see Dordick et al., 2017, for a
review). Often, they request money or other items with little or nothing to give the
donor in return. Panhandlers typically situate themselves in locations of high public
traffic where money may be readily at hand, meaning that while most poor individuals
try to hide their poverty, panhandlers must flaunt it to be successful (Dordick et al.,
2017). Indeed, in locations such as downtown Manhattan, over 10,000 people are
thought to see a panhandler in one afternoon (Dordick et al., 2017).
The majority of panhandlers are men who have been forced into asking for money
because of one or more negative life events (e.g., illness, accident) (Lee & Farrell, 2003).
The majority of panhandlers are substance abusers and due to this, often also have
criminal records (Lee & Farrell, 2003). There is a stereotype that they may also be at
higher rates for violence or mental illness, although research does not support this belief
(Lee & Farrell, 2003; Tsai, Lee, Byrne, Pietrzak & Southwick, 2017). Compared to 1990,
recent national surveys about attitudes toward homeless individuals (including
panhandlers) shows that Americans endorse more support for this group and an increase
in compassion (Tsai, Lee, Byrne, Pietrzak & Southwick, 2017). At the same time, there
have been government movements to prohibit panhandling, which is counterproductive
to alleviating homelessness, possibly because citizens experience a sense of disgust when
they are in close proximity to those asking for money (Clifford, & Piston, 2017).
Pandey et al. (2006) reported that panhandlers experience stigma and feel
marginalized, dehumanized, discriminated against, and alienated, leading them to have
negative views of their personal well‐being. However, in some instances panhandlers
appeared to enjoy the stigma because it directly led to increased donations of items. Due
to the stereotypes about panhandlers, there exists a wide range of emotions and attitudes
towards them as a group, including pity, fear, and anger (Lee & Farrell, 2003).
For the purpose of the current study, panhandlers provide the opportunity for men
to demonstrate their ability to distribute resources in front of potential mates. This
display would show generosity and kindness (both considered preferred traits; Buss,
1989), but also that he possesses sufficient resources that he may give them away freely.
Thus, we hypothesized that due to this behavior being relevant as a mating signal, men
would be most likely to give panhandlers money or other items when in the presence of a
woman, as compared to when they were with another man or alone. By extension, we
also hypothesized that men who were walking alone would provide money and other
items to panhandlers at the same rate as women walking alone. Similar findings were
obtained by Iredale, Van Vugt, and Dunbar (2008); in an experimental game situation,
men were more likely to donate a higher portion of earned money to charity when
observed by women than by men, or with no observer.
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Human Ethology Bulletin 33(2018)4: 28-36
METHODS
Context
The studied individuals (hereby called “participants” although they were blind to their
inclusion in the study) were observed in one of four conditions: (1) women walking
alone past a panhandler, (2) men walking alone past a panhandler, (3) a man walking
with another man past a panhandler, and (4) a man walking with a woman past a
panhandler. Each individual was asked for change by an actual panhandler for that
environment; they were not a confederate for the study. The consequences of their
request were recorded by an observer discretely watching from a short distance away
(e.g., inside a coffee shop or similar location). All observations were made as participants
travelled along a sidewalk toward the panhandler, and neither the participants nor the
panhandler were aware that they were being monitored. Observation ended once the
participant walked past the panhandler.
Observations took place in several downtown locations of Halifax, Canada where
panhandlers select areas of high pedestrian traffic. It was not possible to determine the
nature of the items given to the panhandler without interfering with the interaction.
Consequently, we established a simple criterion that a successful attempt at panhandling
consisted of any item given by the pedestrian and placed into the hand or cup of the
panhandler. We did observe that the majority of items consisted of coins (note that
Canada has a 5, 10, 25 cent coin, as well as a 1 and 2 dollar coin).
Panhandlers were chosen based on the ability of the observer to remain hidden and
undetected in a location of close proximity. Four separate panhandlers were watched in
their interactions with pedestrians. All panhandlers were men, Caucasian, approximately
40-70 years old, were wearing clothes (i.e., large jackets and jeans) that appeared ripped
and dirty, and were without a pet or sign asking for money. All panhandlers requested
money verbally to pedestrians while remaining in a seated position.
Observations occurred over four days, for approximately three hours each day in
total. Each day consisted of a different panhandler in a different location. All data
collection occurred between January and March in the middle of a week day while there
was no precipitation.
Participants
A total of 200 individuals were observed. We observed across the locations until we
obtained a sample of 50 individuals in each of the four conditions. There were no
exclusion criteria, as so long as the participants were of adult age (i.e., looked over the age
of 20) and satisfied the criteria of the condition. Ethnicity varied, although we did notice
that the majority of participants were either of Caucasian or Asian young adults.
We elected to systematically observe every second individual matching the condition
criteria in order to allow the observer sufficient time after the event to complete the
observation and record the result. Pedestrians were excluded if they were walking with
more than one other adult for the dyad conditions, and excluded across all conditions if
they were walking with an animal or child. Pedestrians were also excluded if they had to
pass by another individual within a 5 meter radius around the panhandler (which we had
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Human Ethology Bulletin 33(2018)4: 28-36
marked inconspicuously while the panhandler was absent), as the presence of anyone
other than those involved in the interaction could serve as a potential confounding
variable.
Given the possibility of disgust in relation to panhandling, for the sake of interest we
also recorded whether the pedestrian made physical contact with the panhandler (which
we predicted would be a rare occurrence). We also recorded whether the pedestrian
started use of an electronic device (e.g., a cellular telephone) while approaching the
panhandler, presumably as a way to distract themselves from the interaction. We further
observed whether they made direct eye contact or not with the panhandler. Other
variables such as whether they stood in front of the panhandler or turned around while
in close proximity (e.g., to change direction and avoid the interaction) was also recorded.
Changes in gait speed were documented, given that we expected some individuals to
speed up to avoid the interaction. We note that these changes had to be very clear in
order to be observed reliably.
RESULTS
There are four independent conditions (i.e., male alone, female alone, male dyad, and
female/male dyad) with a binary (yes/no) dependent variable, leading to a 4 X 2
contingency table. Due to the small number of cases (under 5) in all but the female/male
dyad who did give an item to the panhandler, we decided to employ Fisher’s exact test
with the Monte Carlo approximation to determine significance. The comparison was
significant, Fisher’s exact test = 9.947, p = .015 (99% CI = .012 to .018; two-tailed, α = .
05). Some readers may be interested in the Pearson Chi-square value (despite the
minimum cell counts) with the Monte Carlo approximation; χ2(3) = 12.271, p = .006
(99% CI = .004 to .008). Table 1 provides the descriptive results.
Table 1: Percentage of Pedestrians Giving Item(s) to Panhandlers in Presence or
Absence of Others
Condition Percentage (%) Gave Item(s) to Panhandler
Female only Current study
Male only Tovée et al., 1997
Male dyad Tovée et al., 1997
Female/male dyad Voracek & Fisher, 2006
Note. Total sample size was 200, 50 per condition.
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Only 2 of the 200 participants touched the panhandler, both of them men such that
one was walking alone, and the other in the male dyad condition. A total of 14.5% of
pedestrians turned toward an electronic device when approaching the panhandler, 5.5%
stood in front of the panhandler (distributed across the conditions), and 1% (one in the
female only and one in the male only condition) turned around when approaching the
panhandler. Eye contact was made by 27.5% of the pedestrians; although the frequency
varied by condition (24% female only, 36% male only, 8% male dyad, 34% female/male
dyad) it was not significant, Fisher’s exact test = 6.582, p = .09 (note that the cell sizes did
not warrant the Monte Carlo approximation). Pedestrian’s gait speed increased for 39.5%
of the sample, while it slowed for 38.5%; this change was distributed across the
conditions and not significant (speed increase, Fisher’s exact test = 6.686, p = .348; speed
decrease Fisher’s exact test = 4.999, p = .541; approximation again not necessary).
DISCUSSION
Past observational research indicates that men alter their behavior in the presence of
women (e.g., Wilson & Daly, 2004). The aim of the current study was to investigate
men’s displays of resources in the presence versus absence of women, using the
framework of evolved mate preferences. We hypothesized that men would donate money
or other items most often in the presence of women, compared to while walking alone or
in the presence of other men. Our hypothesis was supported. We argued that men
engage in this behavior as a signal to potential mates about their personality
characteristics of kindness and generosity, as well as their current level of resources or
wealth. There exists a large corpus of research that shows women generally favor men
with these traits, at least in terms of self-report data (e.g., Buss, 1989; Buss & Schmitt, in
press; Hunter, Hill, Reid, Bourgeois, & Fisher, in review).
It is key to note that simply the presence of another individual does not lead to the
same outcome. Men walking with another man gave significantly fewer items to
panhandlers than when walking with a woman, and hence, we conclude that it is not
merely the presence of another person that prompts this behavior. While walking with
another male, men do not need to demonstrate generosity or their ability to allocate
resources, which supports our conjecture that this behavior is a display to gain favor with
potential mates. The behavior is also not specific to men, as we found men gave items to
panhandlers as often as women when walking alone, and that it remained significantly
less frequent than the behavior of men in the mixed sex dyads.
Our findings align with those of Iredale, Van Vugt, and Dunbar (2008). In an
experimental game situation, men were more likely to donate a larger portion of their
earned winnings to charity when observed by women, than when observed by men or
when not observed. The researchers attributed this finding to costly signaling, such that
generosity may indicate traits such as kindness and helpfulness. More recently, Van Vugt
and Iredale (2013) replicated this effect, finding groups of men donated more in public
good games when there was a female audience, and that men’s donations positively
increased according to their rating of the women’s attractiveness.
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We note that our observations occurred during the winter months in Canada, but
effort was taken to ensure that the weather conditions as well as other contextual issues
(e.g., time of day, day of the week, temperature) were as close to possible as identical
across the days in which we collected our data. It may be informative to replicate this
study when the weather is warmer, given that pedestrians may behave more leisurely and
be more interactive due to the higher temperature. Ambient temperature is key, as Vanky
and colleagues (2017) findings do not support the potential of a merely seasonality
effect. They gathered GPS data from a mobile telephone tracking application for almost
250 000 trips over 50 weeks by 13688 individuals living in Boston or San Francisco.
They report that regardless of seasonality, ambient air temperature and cloud cover
predict trip frequency, particularly for weekend (and they argue presumably
discretionary) travel. However, weather had minimal impact on the duration of trips,
once a trip was initiated.
One limitation concerns the assumption of pedestrian’s sexual orientation. The
design of this research dictated that we assumed all female/male dyads involved
heterosexual individuals, and that the male/male dyads did not involve displays of
mating-relevant signals. These assumptions, of course, are likely not accurate. Further
research is needed to examine how sexual orientation plays a role in the same sorts of
behaviours observed in this study. Moreover, we do not know the relationship of those
involved in the dyads; it could be that the female/male dyads were romantic partners or
siblings, for example, which likely influences the results and their implications.
Another limitation is that we did not include data from female/female dyads. This
exclusion was due to the focus of the current work on male displays. However, for
completeness, it would be potentially informative to include female/female dyads. We
also could have considered sex of the panhandlers more fully, although observation
suggests that in Halifax, the location of the study, the overwhelming majority of
panhandlers are men. Goldberg (1995) performed a similar study to the current research
and documented that men, when alone, were more likely to donate items to female than
male panhandlers. They also report that men, when accompanied by similarly aged
women, seemed to avoid giving items to female panhandlers and did not give
disproportionately more to male panhandlers, which the author interpreted as men
avoiding “showing off.” Different results were found decades earlier by Latane (1970)
who recorded men were more likely to provide assistance (i.e., tell the time, provide
directions, or give money) than women, and women were more likely to receive help
than men.
The findings of the current study indicate that naturalistic observation of real-world
events may be useful for understanding mate preferences that are typically documented
via self-report surveys. We showed that men are most likely to signal their resources as
well as generosity and kindness in the presence of women, which suggests that they may
have an awareness of female mate preferences and perform these actions in order to be
viewed in a positive manner.
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Human Ethology Bulletin 33(2018)4: 28-36



References, full paper, etc., in the link above.

Just how miserable is work? It seems that not so much... We feel about the same at work than at non-work.

Just how miserable is work? A meta-analysis comparing work and non-work affect. Martin J. Biskup, Seth Kaplan, Jill C. Bradley-Geist, Ashley A. Membere. PLOS One, March 5, 2019. https://doi.org/10.1371/journal.pone.0212594

Abstract: Although we spend much of our waking hours working, the emotional experience of work, versus non-work, remains unclear. While the large literature on work stress suggests that work generally is aversive, some seminal theory and findings portray working as salubrious and perhaps as an escape from home life. Here, we examine the subjective experience of work (versus non-work) by conducting a quantitative review of 59 primary studies that assessed affect on working days. Meta-analyses of within-day studies indicated that there was no difference in positive affect (PA) between work versus non-work domains. Negative affect (NA) was higher for work than non-work, although the magnitude of difference was small (i.e., .22 SD, an effect size comparable to that of the difference in NA between different leisure activities like watching TV versus playing board games). Moderator analyses revealed that PA was relatively higher at work and NA relatively lower when affect was measured using “real-time” measurement (e.g., Experience Sampling Methodology) versus measured using the Day Reconstruction Method (i.e., real-time reports reveal a more favorable view of work as compared to recall/DRM reports). Additional findings from moderator analyses included significant differences in main effect sizes as a function of the specific affect, and, for PA, as a function of the age of the sample and the time of day when the non-work measurements were taken. Results for the other possible moderators including job complexity and affect intensity were not statistically significant.

The drop in homicide represents a public health breakthrough for African American males, almost a year of increase in life expectancy at birth

The Impact of the Homicide Decline on Life Expectancy of African American Males. Patrick Sharkey, Michael Friedson. Demography, https://link.springer.com/article/10.1007/s13524-019-00768-4

Abstract: Homicide is a leading cause of death for young people in the United States aged 15–34, but it has a disproportionate impact on one subset of the population: African American males. The national decline in homicide mortality that occurred from 1991 to 2014 thus provides an opportunity to generate evidence on a unique question—How do population health and health inequality change when the prevalence of one of the leading causes of death is cut in half? In this article, we estimate the impact of the decline in homicide mortality on life expectancy at birth as well as years of potential life lost for African American and white males and females, respectively. Estimates are generated using national mortality data by age, gender, race, and education level. Counterfactual estimates are constructed under the assumption of no change in mortality due to homicide from 1991 (the year when the national homicide rate reached its latest peak) to 2014 (the year when the homicide rate reached its trough). We estimate that the decline in homicides led to a 0.80-year increase in life expectancy at birth for African American males, and reduced years of potential life lost by 1,156 years for every 100,000 African American males. Results suggest that the drop in homicide represents a public health breakthrough for African American males, accounting for 17 % of the reduction in the life expectancy gap between white and African American males.

Are Cheaters Sexual Hypocrites? Sexual Hypocrisy, the Self-Serving Bias, and Personality Style

Are Cheaters Sexual Hypocrites? Sexual Hypocrisy, the Self-Serving Bias, and Personality Style. Benjamin Warach, Lawrence Josephs, Bernard S. Gorman. Personality and Social Psychology Bulletin, March 5, 2019. https://doi.org/10.1177/0146167219833392

Abstract: This article examines moral hypocrisy and the self-serving bias (SSB) in the sexual infidelity context. We found evidence of self-serving attributions that occur between primary relationship partners following sexual betrayals. Specifically, we found that sexual infidelity perpetrators (a) blamed their primary dyadic partners (i.e., victims) for infidelities significantly more than those victims blamed themselves for such infidelities, (b) blamed the surrounding circumstances for infidelities significantly more than their victims did, and (c) rated the emotional impact of infidelities on their victims as significantly less than victims’ ratings of such impact. Moreover, we found that participants with prior experience as both sexual infidelity perpetrators and victims displayed “sexual hypocrisy” by judging others more harshly than themselves for sexually unfaithful behavior. Our findings demonstrate that personality variables associated with sexual infidelity (narcissism, sexual narcissism, avoidant attachment, and primary psychopathy) are also relevant to self-serving attributions in the sexual infidelity context.

Keywords: sexual infidelity, self-serving bias, moral hypocrisy, sexual hypocrisy

“I Would Never Fall for That”: The Use of an Illegitimate Authority ... Marked discrepancy between how students predicted they would respond and how they actually did; the mean obedience rate was 95.7%

“I Would Never Fall for That”: The Use of an Illegitimate Authority to Teach Social Psychological Principles. Sally D. Farley, Deborah H. Carson, Terrence J. Pope. Teaching of Psychology, Mar 5 2019. https://doi.org/10.1177/0098628319834200

Abstract: This activity explores attitudinal beliefs and behavioral responses of obedience to an illegitimate authority figure in an ambiguous situation. In Experiment 1, students either self-reported the likelihood that they would obey a request made by a stranger to surrender their cell phone or were asked directly and in person by a confederate to relinquish their cell phone. The exercise revealed a marked discrepancy between how students predicted they would respond and how they actually did respond to the request. In Experiment 2, student learning was measured in addition to obedience. Although students exposed to the exercise had similar gains in learning as those exposed to a control condition, the mean obedience rate was a compelling 95.7%. Furthermore, students self-reported a greater willingness to obey the commands of an authority figure after learning about the Milgram study than before, thereby acknowledging their vulnerability to authority. We discuss the role of Milgram’s study in the psychology curriculum and provide recommendations for how this exercise might assist understanding of myriad social psychological principles.

Keywords: Hofling, Milgram, exercise, authority, obedience

Tuesday, March 5, 2019

Is Empathy the Default Response to Suffering? A Meta-analytic Evaluation of Perspective-taking’s Effect on Empathic Concern

McAuliffe, William H., Evan C. Carter, Juliana Berhane, Alexander Snihur, and Michael E. McCullough. 2019. “Is Empathy the Default Response to Suffering? A Meta-analytic Evaluation of Perspective-taking’s Effect on Empathic Concern.” PsyArXiv. March 5. doi:10.31234/osf.io/bwxm9

Abstract: We conducted a series of meta-analytic tests on experiments in which participants read perspective-taking instructions—i.e., written instructions to imagine a distressed persons’ point of view (“imagine-self” and “imagine-other” instructions), or to inhibit such actions (“remain-objective” instructions)—and later reported how much empathic concern they experienced after learning about the distressed person. If people spontaneously empathize with others, then participants who receive remain-objective instructions should report less empathic concern than do participants who do not receive instructions; if people can deliberately increase how much empathic concern they experience, then imagine-self and imagine-other instructions should increase empathic concern relative to not receiving any instructions. Random-effects models revealed that medium-sized differences between imagine and remain-objective instructions were driven by remain-objective instructions. The results were robust to most corrections for bias. Publication status, in-group status, and the medium by which participants learned about the perspective-taking target did not emerge as robust moderators.

Multiple sclerosis and sugar-sweetened beverages: "and the results do not show that soda and sugar-sweetened beverages cause more severe disability"

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May someone explain to me this headline?:
SODA, SUGAR-SWEETENED BEVERAGES LINKED TO MORE SEVERE SYMPTOMS FOR PEOPLE WITH MS. American Academy of Neurology, Mar 05 2019.
https://www.aan.com/PressRoom/Home/PressRelease/2701.

Inside, it says:
While these results need to be confirmed by larger studies that follow people over a long period of time, and the results do not show that soda and sugar-sweetened beverages cause more severe disability, we do know that sodas have no nutritional value and people with MS may want to consider reducing or eliminating them from their diet,” Meier-Gerdingh said.

???



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The Politics of Beauty: The Effects of Partisan Bias on Physical Attractiveness

From 2016... The Politics of Beauty: The Effects of Partisan Bias on Physical Attractiveness. Stephen P. Nicholson, Chelsea M. Coe, Jason Emory,  Anna V Song. Political Behavior 38(4), April 2016. DOI: 10.1007/s11109-016-9339-7

Abstract: Does politics cause people to be perceived as more or less attractive? As a type of social identity, party identifiers often exhibit in-group bias, positively evaluating members of their own party and, especially under conditions of competition, negatively evaluating out-party members. The current experiment tests whether political in-party and out-party status affects perceptions of the physical attractiveness of target persons. In a nationally representative internet sample of U.S. adults during the 2012 presidential election, we presented participants with photos of individuals and varied information about their presidential candidate preference. Results indicate that partisans, regardless of gender, rate target individuals as less attractive if they hold a dissimilar candidate preference. Female partisans, however, were more likely to rate target persons as more physically attractive when they held a similar candidate preference whereas no such effect was found for male partisans.

Using data covering a wide range of municipal public-sector pension plans from 1962– 2014, I establish that unfunded pension benefits grow faster under Democratic-party mayors

Political Parties Do Matter in U.S. Cities ... For Their Unfunded Pensions. Christian Dippel. NBER Working Paper No. 25601, Feb 2019. https://www.nber.org/papers/w25601

Abstract: Using data covering a wide range of municipal public-sector pension plans from 1962– 2014, I establish that unfunded pension benefits grow faster under Democratic-party mayors. The result is borne out in a generalized difference-in-differences (DiD) specification in levels and in growth rates as well as in a regression discontinuity design (RDD) focusing on narrow mayoral races. There is some evidence that the partisan effect is concentrated in police and fire-fighter plans. Being on a council-manager system matters very little to these patterns. While Tiebout sorting has been the proposed explanation for previous findings that parties do not matter for a range of fiscal outcomes in U.S. cities, Tiebout sorting may actually accentuate fiscal profligacy in the case of unfunded pensions.

The majority of regular patrons were dissatisfied with current sound levels, with around three-quarters of participants reporting preferences below the levels typically experienced at music venues

Time to listen: Most regular patrons of music venues prefer lower volumes. Elizabeth F. Beach and Megan Gilliver. Front. Psychol., Mar 5 2019. doi: 10.3389/fpsyg.2019.00607

Abstract: High sound levels are a feature of nightclubs and live music venues, and therefore pose a risk to patrons’ hearing. As a result, these venues are often a focus area for hearing health promotion, and particular emphasis is placed on motivating patrons to take steps to reduce their noise exposure. In the current study, we approached this issue from a different angle. We asked whether sound levels in music venues accurately reflect the preferences of regular patrons, and examined their attitudes and preferences towards sound levels and protective listening behaviours. The study examined results from 993 regular patrons of nightclubs and live music venues, collected as part of an Australian online hearing health survey. Participants were asked about their participation at the two target venues, experiences of hearing difficulties, and risk perceptions. They were also asked about their preferences in relation to typical venue sound levels and beliefs about other attendees’ preferences. Results showed that while participants generally rated their hearing as good, the majority had experienced hearing difficulties following sound exposure at music venues. The majority of regular patrons were dissatisfied with current sound levels, with around three-quarters of participants reporting preferences below the levels typically experienced at music venues. Participants were generally aware of the risk posed by high sound levels and those who regarded themselves to be at greater risk from attending music venues were more likely to prefer lower sound levels. These findings have important consequences for the development of hearing health initiatives within entertainment venues. Rather than motivating patrons to change their behavior, encouraging venues to meet their patrons’ needs and preferences may be a more successful strategy. Venue operators may find that this approach has a positive impact not only on the hearing health of patrons, but also on the economic health of their venue. Ultimately, reducing the hearing risk in music venues may best be achieved not by telling people what to do, but by listening to what they actually want.

Keywords: live music, Nightclubs, Sound Levels, loudness preferences, Hearing Loss, Tinnitus, Leisure noise, music venue patrons

The meta-analysis provides additional evidence that extraversion is related to belief in free will

Extraversion and compatibilist intuitions: a ten-year retrospective and meta-analyses
Adam Feltz & Edward Cokely. Philosophical Psychology, Mar 4 2019. https://doi.org/10.1080/09515089.2019.1572692 

ABSTRACT: The past ten years have seen multiple attempts to estimate the relation between the global personality trait extraversion and compatibilist free will judgments. Here, we contribute to that line of research by conducting a meta-analysis of 17 published and eight unpublished studies (N = 2,811) estimating that relation. Overall, the mean effect size was modest but remarkably robust across materials, locations, and labs (z = .19, 95% CI .15-.24, p < .001). No significant publication bias was detected in the studies (t (23) = 1.88, p = .07). While there was no significant heterogeneity in the studies (Q (24) = 34.42, p = .08, I2 = 26.05), a moderator analysis suggested that the effect is strongest in cases that contain highly affective actions (e.g., murder) (z = .22, 95% CI .17-.28, p < .001) and weakest in cases that contain actions with low affect (e.g., asking whether free will is compatible with determinism) (z = .09, 95% CI -.05-.23, p = .22). The meta-analysis provides additional evidence that extraversion is related to compatibilist free will judgments and helps to identify opportunities to discover boundary conditions and more proximal causal mechanisms for the relation. The results of the meta-analysis also have implications for informed decision making.

KEYWORDS: Free will, compatibilism, determinism, experimental philosophy, meta-analysis, personality


The first systematic review and meta-analysis on laughter-inducing therapies: Overall quality of evidence was low; this research field has yet to reach maturity

Laughter-inducing therapies: Systematic review and meta-analysis. C. Natalie van der Wal, Robin N.Kok. Social Science & Medicine, https://doi.org/10.1016/j.socscimed.2019.02.018

Highlights
•  The first systematic review and meta-analysis on laughter-inducing therapies.
•  Overall quality of evidence was low; this research field has yet to reach maturity.
•  Non-humorous laughter attains higher effect sizes than humorous laughter.
•  Laughter-inducing therapies may improve depression, anxiety, and perceived stress.
•  Therapies seem feasible in terminal, immobile or cognitive impaired conditions.

Abstract
Rationale: Laughter-inducing therapies are being applied more regularly in the last decade, and the number of scientific reports of their beneficial effects is growing. Laughter-inducing therapies could be cost-effective treatments for different populations as a complementary or main therapy. A systematic review and meta-analysis has not yet been performed on these therapies, but is needed to examine their potential benefits. This research aims to broadly describe the field of laughter-inducing therapies, and to estimate their effect on mental and physical health for a broad range of populations and conditions.

Method: A systematic review of the field was undertaken, followed by a meta-analysis of RCTs and quasi-experimental studies. The systematic review included intervention studies, one-session therapies, lab studies and narrative reviews to provide a broad overview of the field. The meta-analysis included RCTs or quasi-experimental studies that assessed multi-session laughter or humor therapies compared to a control group, performed on people of any age, healthy or with a mental or physical condition. English and non-English articles were searched using PubMed, Web of Science, EBSCO and EMBASE. Search terms included laugh(ing), laughter, humo(u)r, program, therapy, yoga, exercise, intervention, method, unconditional, spontaneous, simulated, forced. Studies were classified as using humor (‘spontaneous’ laughter) or not using humor (‘simulated’ laughter).

Results: This systematic review and meta-analysis suggests that (1) ‘simulated’ (non-humorous) laughter is more effective than ‘spontaneous’ (humorous) laughter, and (2) laughter-inducing therapies can improve depression. However, overall study quality was low, with substantial risk of bias in all studies. With rising health care costs and the increasing elderly population, there is a potential for low-cost, simple interventions that can be administered by staff with minimal training. Laughter-inducing therapies show a promise as an addition to main therapies, but more methodologically rigorous research is needed to provide evidence for this promise.

Keywords: Laughter-inducing therapySpontaneous laughterSimulated laughterHumorPsychological and physical well-beingSystematic reviewMeta-analysis

Looking for Mr(s) Right: Decision bias can prevent us from finding the most attractive face

Looking for Mr(s) Right: Decision bias can prevent us from finding the most attractive face. Nicholas Furl, Bruno B. Averbeck, Ryan T.McKay. Cognitive Psychology, Volume 111, June 2019, Pages 1-14. https://doi.org/10.1016/j.cogpsych.2019.02.002

Highlights
• Many decisions involve searching option sequences and trying to stop on best option.
• Our participants were biased to search too long for attractive faces.
• This bias differs from other kinds of searches, where participants stop too early.
• Participants are risk-prone, only considering rare, highly-attractive faces.
• Participants could use probabilistic reasoning, as described by Bayesian models.

Abstract: In realistic and challenging decision contexts, people may show biases that prevent them from choosing their favored options. For example, astronomer Johannes Kepler famously interviewed several candidate fiancées sequentially, but was rejected when attempting to return to a previous candidate. Similarly, we examined human performance on searches for attractive faces through fixed-length sequences by adapting optimal stopping computational theory developed from behavioral ecology and economics. Although economics studies have repeatedly found that participants sample too few options before choosing the best-ranked number from a series, we instead found overlong searches with many sequences ending without choice. Participants employed irrationally high choice thresholds, compared to the more lax, realistic standards of a Bayesian ideal observer, which achieved better-ranked faces. We consider several computational accounts and find that participants most resemble a Bayesian model that decides based on altered attractiveness values. These values may produce starkly different biases in the facial attractiveness domain than in other decision domains.

Keywords: Decision makingBayesian modelingFacial attractivenessMate choiceOptimal stopping

Robots enchanting humans, particularly the phenomenon of robots being perceived by humans as “magical” enough to develop intimate relationships with them (caring robots, sex robots)

Robots Enchanting Humans. Maciej Musiał. Chapter in Enchanting Robots: Intimacy, Magic, and Technology, pp 11-62. March 01 2019. https://link.springer.com/chapter/10.1007/978-3-030-12579-0_2

Abstract: The chapter discusses the issue of robots enchanting humans, particularly the phenomenon of robots being perceived by humans as “magical” enough to develop intimate relationships with them. To examine this problem, this chapter explores the current debates in the field of robot ethics that address sex robots and care robots. It investigates both the arguments of those who are enthusiastic about such robots as well as the positions of skeptics, who consider intimate relationships with robots to be a serious danger. Finally, in reference to sociological studies about transformations of intimacy it is argued that robots enchant humans and are perceived as potential intimate partners because humans are becoming progressively disenchanted in the sense that they are increasingly considered to be non-unique and problematic, while robots are seen as possessing all positive characteristics of humans without any flaws typical of humans.

Keywords: Intimacy Intimate relationships Sex robots Care robots Objectification

The same bias that causes someone to take an exploitative loan may also imply that the loan benefits them by causing them to purchase a product or service that they should, but wouldn’t otherwise, buy

Hayashi, Andrew T., Consumer Law Myopia (February 14, 2019). Virginia Law and Economics Research Paper No. 2019-03. https://ssrn.com/abstract=3334677

Abstract: People make mistakes with debt, partly because the chance to buy now and pay later tempts them to do things that are not in their long-term interest. Lenders sell credit products that exploit this vulnerability. In this Article, I argue that critiques of these products, particularly those that draw insights from behavioral law and economics, have a blind spot: they ignore what the borrowed funds are used for. By evaluating financing transactions in isolation from the underlying purchase, the cost-benefit analysis of consumer financial regulation is truncated and misleading. I show that the same bias that causes someone to take an exploitative loan may also imply that the loan benefits them by causing them to purchase a product or service that they should, but wouldn’t otherwise, buy. I demonstrate the importance of this effect in a study of tax refund anticipation loans. I find that regulation curtailing these loans reduced the use of paid tax preparers and the takeup of the earned income tax credit, which is the second largest federal transfer to low-income households.

Keywords: behavioral law and economics, consumer law

Consumers with food deprivation display lower preference for sustainable food items; hunger operates outside rational awareness and alters gentleness-associations with sustainable products

Hungry bellies have no ears. How and why hunger inhibits sustainable consumption. Stefan Hoffmann et al. Ecological Economics, Volume 160, June 2019, Pages 96-104. https://doi.org/10.1016/j.ecolecon.2019.02.007

Highlights
•    Consumers with food deprivation display lower preference for sustainable food items.
•    Implicit Association Test shows that hunger operates outside rational awareness.
•    Hunger alters gentleness-associations with sustainable products.
•    Explicitly held judgments are not affected by food deprivation.

Abstract: While reports state that consumers are increasingly willing to consume more sustainably, no study has considered how the activation of very basic human needs, such as the state of hunger, affects sustainable food consumption. The authors expect that hungry consumers display a lower preference for sustainable food items and that this hunger-induced imprint on food consumption patterns must be traced back to the fact that the activation of very fundamental human needs contaminates stereotypical perceptions of sustainable products. More importantly, hunger primarily operates spontaneously, as well as automatically, and affects perceptions, which are difficult to control (and which sometimes go unnoticed). A laboratory experiment studied this premise by sampling 166 participants with 18 h of actual food deprivation, half of them having breakfast before and the other half after completing the experimental tasks. The participants who had breakfast show a stronger tendency to choose sustainable products, which can be traced back to implicit gentleness-associations concerning sustainable products in the Implicit Association Test (IAT). Albeit explicitly held beliefs also influence choices, these judgments are not affected by food deprivation. A field study then replicates the findings in a real-life setting.

Monday, March 4, 2019

Why Women Leave Their Husbands for Other Women

Why Women Leave Their Husbands for Other Women. Lauren Vinopal. Fatherly, Mar 04 2019. https://www.fatherly.com/health-science/women-bisexual-divorce/

Women are more likely to leave their husbands for other women because their sexual fluidity comes with fewer consequences.

Women are more likely than men to cheat on their spouses with a same-sex partner, studies suggest. It’s not that women are more likely to be homosexual or bisexual—it’s that women appear more willing than men to change their minds about what turns them on, throughout their lives. Men tend to choose a sexuality and stick with it, experts agree. Women are sexual wildcards.

“I think data are sufficient to suggest that more women are likely to change their reported sexual orientation depending on their circumstance, where men are more resistant to changing their identity from sexual behavior alone,” psychophysiologist and neuroscientist Nicole Prause, who studies women’s sexual responses, told Fatherly.

The phrase “sexual fluidity” was originally coined by psychologist Lisa Diamond in 2008. After following the same 100 women for a decade, she found that there were crucial differences between bisexuality and the sexual fluidity that otherwise heterosexual women experienced. Bisexuality is defined as being attracted to men and women. Many women, Diamond found, identified as gay or straight, but accepted the fact that they might change their minds at some point. When experts say that women are more likely to be sexually fluid, they mean that they’re more likely to make an exception to, or even update, their sexual identities.

Of course, this does not mean that women are more likely than men to cheat on their spouses and sexual fluidity is seldom the main cause of a relationship souring. As with any relationship problem, there are usually other, deeper relationship issues at play. But now, more than ever, married women are stepping away from problem heterosexual marriages, and into same-sex ones.

[...]

One hormonal explanation may be that women’s testosterone levels increase with age, and higher testosterone levels have also been linked with increased incidence of homosexuality and bisexuality in women. This might help explain why women may be more fluid in their thirties and forties, after having kids. Evolutionary psychologists have offered a number of theories as to why women may be more fluid as well, such as an adaptive way to decrease conflict in polygamous cultures. Another popular explanation is that, because saying yes to sex comes at a higher risk and reproductive cost to women, they tend to make sexual decisions more cautiously on a case by case basis, which could potentially allow for more deviation.

Still, it is likely that increased rates of sexual fluidity among women is primarily a social (rather than biological) phenomenon. Indeed, there is emerging evidence that men have the same potential as women to be sexually fluid, but that stigma prevents them from acting upon it. In most western societies, women still face fewer social costs for same-sex relationships than men. [...]

Psychological sex differences in humans are real, they can be large and even very large, and evidence suggests evolutionary origins for a broad range of sex differences

Archer, John  (2019) The reality and evolutionary significance of human psychological sex differences. Biological Reviews, https://doi.org/10.1111/brv.

Abstract: The aims of this article are: (1) to provide a quantitative overview of sex differences in human psychological attributes, and (2) to consider evidence for their possible evolutionary origins. Sex differences were identified from a systematic literature search of meta-analyses and large-sample studies. These were organized in terms of evolutionary significance as follows: (1) characteristics arising from inter-male competition (within-sex aggression; impulsiveness and sensation-seeking; fearfulness; visuospatial and object-location memory; object-centred orientations); (2) those concerning social relations that are likely to have arisen from women’s adaptations for small-group interactions and men’s for larger co-operative groups (person-centred orientation and social skills; language; depression and anxiety); (3) those arising from female choice (sexuality; mate choice; sexual conflict). There were sex differences in all categories, whose magnitudes ranged from (1) small (object location memory; negative emotions), to (2) medium (mental rotation; anxiety disorders; impulsivity; sex drive; interest in casual sex), to (3) large (social interests and abilities; sociosexuality), and (4) very large (escalated aggression; systemizing; sexual violence). Evolutionary explanations were evaluated according to whether: (1) similar differences occur in other mammals; (2) there is cross-cultural consistency; (3) the origin was early in life or at puberty; (4) there was evidence for hormonal influences; and (5), where possible, whether there was evidence for evolutionarily derived design features. The evidence was positive for most features in most categories, suggesting evolutionary origins for a broad range of sex differences. Attributes for which there was no sex difference are also noted. Within-sex variations are discussed as limitations to the emphasis on sex differences.