Across 58 published studies in 23 species, we find strong evidence that animals copy the mate choice of others

A meta-analysis of factors influencing the strength of mate-choice copying in animals. Alice D Davies, Zenobia Lewis, Liam R Dougherty. Behavioral Ecology, araa064, July 9 2020. https://doi.org/10.1093/beheco/araa064

Abstract: Mate-choice copying is a form of social learning in which an individual’s choice of mate is influenced by the apparent choices of other individuals of the same sex and has been observed in more than 20 species across a broad taxonomic range. Though fitness benefits of copying have proven difficult to measure, theory suggests that copying should not be beneficial for all species or contexts. However, the factors influencing the evolution and expression of copying have proven difficult to resolve. We systematically searched the literature for studies of mate-choice copying in nonhuman animals and, then, performed a phylogenetically controlled meta-analysis to explore which factors influence the expression of copying across species. Across 58 published studies in 23 species, we find strong evidence that animals copy the mate choice of others. The strength of copying was significantly influenced by taxonomic group; however, sample size limitations mean it is difficult to draw firm conclusions regarding copying in mammals and arthropods. The strength of copying was also influenced by experimental design: copying was stronger when choosers were tested before and after witnessing a conspecific’s mate choice compared to when choosers with social information were compared to choosers without. Importantly, we did not detect any difference in the strength of copying between males and females or in relation to the rate of multiple mating. Our search also highlights that more empirical work is needed to investigate copying in a broader range of species, especially those with differing mating systems and levels of reproductive investment.

DISCUSSION

We performed a meta-analysis of 158 effect sizes from 58 published studies of mate-choice copying in nonhuman animals. Overall, we find strong evidence that animals copy the mating preferences of others. The overall standardized mean difference was 0.57 (95% CI = 0.34–0.81), which is considered a medium effect (Cohen 1992). This converts to a mean odds ratio of 2.83 so that the observers in this sample are almost three times as likely to choose a partner or phenotype that they previously observed in a positive sexual interaction with a rival compared to individuals with no social information. This result suggests that social information can have a significant influence on animal mating preferences across a wide range of species. Further, the strength of copying observed is similar to that reported in the recent meta-analysis of female copying by Jones and DuVal (2019: a mean odds ratio of 2.71), of which our data set overlaps. We also detected significant variation in the degree of copying across species, which was partly explained by taxonomic group: copying was strongest for mammals and weakest for arthropods. The strength of copying was also influenced by the type of experiment used to test for copying: copying was stronger when studies compared mating behavior before and after the presentation of social information in contrast to studies in which separate control and social treatment groups were compared. Interestingly, we did not detect any difference in copying between males and females or in relation to the rate of multiple mating. We also detected little evidence for publication bias against nonsignificant results.

Whereas evidence suggests that mate-choice copying is taxonomically widespread, a small number of model species are overrepresented in our data set and in the literature more generally: of the 89 studies identified in our search, 20 focus on guppies, 9 on Japanese quail, and 9 on D. melanogaster. Despite this, species identity explained a small proportion of the variation in effect size in our analysis. This confirms that copying is not driven by a few influential species and that within-species variability in effect size is high. Phylogenetic history explained only a small amount of variation in effect sizes, indicating that any similarities between species are not due to them being closely related evolutionarily. This is unsurprising, given the large evolutionary distances between the species in the data set (with the exception of species in the Poeciliidae) and the evolutionary lability of behavioral traits (Blomberg et al. 2003). Nevertheless, we did detect differences in the degree of copying when we sorted the species in our data set into four broad taxonomic groups: mammals, birds, fishes, and arthropods (incorporating insects, arachnids, and crustaceans). The degree of copying was highest for mammals, followed by birds and fishes, and then lowest for arthropods. This finding could be explained by broad-scale differences in cognitive ability, ecological conditions, or social group size. However, these results should be interpreted with caution: first, because the number of effect sizes for mammals and arthropods was small and, second, because the small number of species tested across the entire data set means it is unclear how generalizable these results are. Importantly, we need more tests of copying in species groups other than those highlighted here. For example, to our knowledge, there have been no experimental tests of copying in amphibians, reptiles, or nonhuman primates.

We found that the type of experimental design significantly influenced the degree of copying. Copying was stronger for studies with a “before-and-after” design compared to studies with separate control and social treatment groups (no pretest). This is the opposite of what we predicted based on our hypothesis that no pretest studies may often underestimate preferences in the absence of social information. We note, however, that our categories of “before-and-after” and “no pretest” designs mostly align with the “random” and “unattractive” categories used by Jones and Duval (2019), which relate to whether the study used a reversal paradigm to test for copying (the unattractive category). The alignment comes from the fact that the reversal paradigm is a subset of the “before-and-after” test. Accordingly, Jones and DuVal (2019) found that copying was stronger when using a reversal paradigm, which is consistent with our result shown here. One potential explanation for the observed effect could be related to the fact that before-and-after designs test each individual twice, potentially in quick succession. This provides the opportunity for observers to gain experience that could influence their choice in a nonrandom way. For example, individuals may become choosier with successive encounters because they have more information on the quality of mates in the population, they perceive mate density to be higher, or because they are attempting to “trade-up” from previous mates (e.g., Pitcher et al. 2003).

There were several moderators which did not significantly influence the degree of copying. For example, copying was performed to a similar extent in animals born in the wild or in captivity. This, first, confirms that mate-choice copying is not an artifact of captivity—it is a real behavior that exists in wild populations. However, the recent meta-analysis by Jones and DuVal (2019) found that females copied more when tested in the wild compared to when tested in captivity. This discrepancy likely arises because our moderator focuses on observer history prior to, but not during, the behavioral tests and suggests that the environment during the test is more important for influencing copying behavior. Copying was not influenced by the mating rate of the species tested. This null result could be explained partly by the lack of data on species with low rates of multiple mating, and we suggest that more studies should be carried out on such species. Importantly, any conclusions relating to this moderator may also be further limited by the fact that species with low rates of multiple mating are taxonomically limited in our sample, occurring only in birds and arthropods. Nevertheless, mate-choice copying has been shown in at least two bird species that show some form of social monogamy and biparental care (zebra finches and Japanese quail), even though theory suggests that copying should not be favored because of the diminishing returns associated with sharing a mate that provides direct benefits or parental care (Vakirtzis and Roberts 2009). We also found no difference in the strength of generalized versus individual copying. These two forms of copying may require different cognitive abilities, but whether this leads to differences in the strength of copying is not clear. Crucially, the relative prevalence, and strength, of these two forms of copying has important evolutionary consequences. Both forms of copying can widen the gap between attractive and unattractive males (Leadbeater 2009), create frequency-dependent bias in mate choice (Santos et al. 2014) and support the invasion of new traits into a population (Santos et al. 2017). However, because generalized copying allows learned preferences to be applied to multiple mates, it can lead to the cultural transmission of preferences, and so has the potential to be a much stronger evolutionary force than individual copying.

Most surprisingly, we found no evidence that males copy less than females. This result is unexpected as males may be substantially increasing their exposure to sperm competition by copying the mate choices of their rivals (Simmons 2001; Vakirtzis and Roberts 2009). In support of this, there is widespread evidence that males often prefer to mate with virgin females if given the choice (Bonduriansky 2001; Simmons 2001). Again, this could be partly explained by the relatively small number of studies testing male copying. Another possibility is that when faced with previously mated females, males may ejaculate more sperm as a defense against combat sperm competition, instead of rejecting a mating opportunity (Simmons 2001; Kelly and Jennions 2011). The ability of males to strategically allocate sperm in this way has the potential to reduce the costs of copying a rival’s choice. Copying could also be beneficial to males if they can reduce the risk of being copied themselves, perhaps by mating or courting out of view of rival males (Simmons 2001; Brown et al. 2012; le Roux et al. 2013) or by mating with less-preferred females when rivals are present as a form of deception (also known as the “audience effect”: Plath et al. 2008; Castellano et al. 2016; Witte et al. 2018). Alternatively, male mate-choice copying may be likely when males face high costs of reproduction as appears to be the case for the fantail darter Etheostoma flabellare, the three-spined stickleback Gasterosteus aculeatus, and the broadnosed pipefish Syngnathus typhle (Witte et al. 2015). Indeed, mate-choice copying studies have often been performed using species with paternal care (fish and zebra finches) and, therefore, high male reproductive investment. It will, therefore, be useful to test for copying in species that exhibit a broader range of mating systems and reproductive strategies than that shown by the current available sample.

Several other aspects of experimental design did not influence the degree of mate-choice copying. For example, copying was observed regardless of the type of social information available to the observer (whether the demonstrator mated, courted, avoided, or affiliated with a partner), how the observer preference was measured, or whether the demonstrator was allowed to “choose” a target individual or was artificially placed with one. Nevertheless, variations in other aspects of experimental design do have the potential to contribute to some of the unexplained variability in effect sizes seen across studies. For example, for indirect measures of mate choice (Rosenthal 2017), the criteria used to determine mating preferences differ between studies. Vukomanovic and Rodd (2007) conducted mate-choice copying experiments with the sailfin molly P. latipinna using different criteria to investigate how this could influence the measurement of copying. Using the criteria of Dugatkin (1992), where females had to spend over 50% of their time within a 13-cm “preference zone” in front of the male, significant copying was detected. However, using the criteria of Lafleur et al. (1997), where females had to spend 15 consecutive seconds in a 2.5-cm preference zone, no copying was detected. This demonstrates that even when recording the same behaviors, results can differ depending on exactly which methodology is used.

Though several moderators did influence the strength of copying in our sample, most of the heterogeneity in effect size detected (both here and in Jones and DuVal 2019) remains unexplained. This suggests that there are other factors that influence the degree of copying, which we were unable to include in our meta-analysis. In many cases, this is because of the difficulty associated with obtaining good estimates across all species sampled. For example, a potentially important driver of copying, and mate choice in general, is the cost of mate sampling. However, we have very few estimates of the costs of mate sampling and mate choice in any species so that broad-scale comparisons are difficult (Rosenthal 2017). Interestingly, empirical studies that have attempted to indirectly measure this effect, by testing copying in high-cost environments, have failed to find any significant change in copying (Briggs et al. 1996; Dugatkin and Godin 1998). Another key driver of copying is expected to be the ability to assess mate quality, which again will be difficult to accurately estimate for all species. However, empirical tests have found some support for this effect: for example, copying is more likely when mates are more similar in guppies and mollies (Dugatkin 1996; Witte and Ryan 1998). Related to this, a valuable topic for future research would be the nature of memory in the context of mate-choice copying. How long are demonstrations remembered for? How easily are these memories forgotten or overwritten with conflicting experiences?

In summary, this meta-analysis of 58 experimental studies suggests that mate-choice copying is a widespread and robust phenomenon across the animal kingdom. Despite different methodological approaches, the average effect size is very similar to that found in the recent meta-analysis of mate-choice copying by Jones and DuVal (2019), of which our data set overlaps. We found evidence that the amount of copying differs significantly across taxonomic groups and between the two main types of experimental design found in the literature but no evidence that copying is influenced by sex or the rate of multiple mating. Importantly, our systematic review has also revealed areas where more empirical work is needed. Unfortunately, though mate-choice copying has been observed across a wide taxonomic range, most studies are still only performed on a few model species. In addition to uncovering the details of how mate-choice copying operates within a species, time should be taken to investigate how widespread the phenomenon is across the animal kingdom and which aspects of a species’ ecology or biology predispose the evolution of copying.

Despite the fact that the time-of-day manipulation successfully influenced participants’ self-reported alertness levels, the time-of-day did not affect guilt judgments or sensitivity to case information

David L. Dickinson & Andrew R. Smith & Robert McClelland, 2019. "An Examination of Circadian Impacts on Judgments," Working Papers 19-11, Department of Economics, Appalachian State University. https://ideas.repec.org/p/apl/wpaper/19-11.html

Abstract: Many people suffer from insufficient sleep and the adverse effects of sleep deprivation or chronic sleep restriction are well documented. Relatedly, recent research has shown that people’s judgments and decisions can be affected by circadian timing. We contributed to this literature by examining time-of-day impact on people’s judgments about hypothetical legal scenarios, hypothesizing that participants responding at a suboptimal time of day (3-5 AM) would give higher guilt ratings and be less sensitive to case information (e.g., evidence strength) than participants responding at a more optimal time of day (2-4 PM). Despite the fact that the time-of-day manipulation successfully influenced participants’ self-reported alertness levels, the time-of-day did not affect guilt judgments or sensitivity to case information. Exploratory analyses found that chronic daytime sleepiness coupled with suboptimal time-of-day impacted participants’ judgments. This adds to the broader literature on how extraneous factors may impact probability assessments, and these results suggest that circadian timing might differentially affect people depending on other contributing factors.

Key Words: Sleep deprivation; Circadian mismatch; Judgments; Bayesian choice

Eminent jurist: Though India has adhered to the [One China policy], New Delhi should find ways to violate it, if not in letter, then in spirit

Chanakya can trump Confucius, writes Abhishek Manu Singhvi. Hindustan Times, Jul 09, 2020. https://www.hindustantimes.com/analysis/chanakya-can-trump-confucius-writes-abhishek-manu-singhvi/story-EdTsV1TSmooZyzm3IHwLAJ.html
India needs to have a comprehensive diplomatic, strategic and economic plan to take on China


China is not only responsible for the spread of the Wuhan virus, but has used this crisis to fulfil its expansionist agenda, to inaugurate what its president defines as China’s “New Era” to its preamble. A major amendment to the Chinese constitution was passed unnoticed, adding “Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era” into its preamble. The Belt and Road Initiative (BRI) is the most ill-concealed example of imperialism. That China has reached thus far in its expansionism is a tribute to its focus, tenacity and persistence.

A country whose nationhood idea hardly existed before 1912 is now claiming both contiguous territories as also geographically far away ones. From Mongolia to Manchuria, from Tibet to Taiwan, the list is endless. The Communist regime is even ready to take on Russia, by claiming authority over Vladivostok. The current stand-off in eastern Ladakh is but a small blip in its bigger world view. Facing enemies on two fronts and fighting the pandemic makes it tough for India. This, however, is when the tough must get going.

On the diplomatic front, there is a need to rethink and reject India’s “One China Policy”. Why should India continue to recognise “One China” if it stabs India in the back and tries to undermine “One India”, by salami-slicing at different points? Though India has adhered to the policy, New Delhi should find ways to violate it, if not in letter, then in spirit. Let us establish diplomatic relations with Taiwan and support the freedom movement in Tibet. The democratic movement in Hong Kong is receiving massive worldwide support. We merely need to add our voice at diverse forums. There are ways of doing all this while retaining official plausible deniability, and, yet, not missing the slightest opportunity to needle, embarrass and shame China. Indeed, we need to go further to underline human rights violations in Xinjiang (East Turkestan) and give oblique support to the Uighur and Turkic communities in their struggle. In 2016, India denied a visa to the famous Uighur leader, Dolkun Isa, to attend a conference of communities persecuted by China in Dharamshala. This is the time to provide unequivocal support to the Uighurs.

Indian parliamentarians should join the Inter-Parliamentary Alliance on China, consisting of hundreds of legislators from eight countries and the European Union. The alliance has taken some prominent initiatives within a month of its creation. Yes, China will internationalise Jammu and Kashmir (J&K), but India’s restraint is doing nothing to stop it. Didn’t China attempt to block the attempt to designate Masood Azhar as a terrorist? Hasn’t it, in the past year, repeatedly taken up the issue of J&K at the United Nations? No. So, India has nothing to lose but its inhibitions.


Strategically, India must strengthen and streamline the working of global alliances against China. The global ambience has never been more conducive, given the anti-Chinese sentiment. Make the working of the Quad — India, the United States (US), Japan, Australia — active and ensure greater concrete cooperation qua the Indo-Pacific. There is urgent need to play a leadership role in the Democracy-10 alliance, comprising G7 plus India, Australia and South Korea. India should strengthen its diplomatic ties with Vietnam and the Philippines and provide them with resources. The US, especially President Donald Trump, is always an unpredictable ally, but at least till the November elections, Trump will do anything to critique China. It is we who must unabashedly know how far to leverage his electoral, anti-China instincts.

Economically, Chinese imports to India have been significantly declining, falling to $48.66 billion in FY 2019-20 from $63 billion in FY 2017-18. The major imports from China include electrical and electronic equipment, plastics, watches, toys, furniture, sports products, iron and steel, metals, chemicals, pharmaceuticals and fuel. We need a judicious mix of import substitution, discriminatorily skewed tariffs and steep anti-dumping duties, apart from bans in patent or gross cases. It is a misconception that these multi-pronged, shrewdly-designed measures will fall foul of the World Trade Organization (WTO). First, a specific level of protection for specific import categories is in accordance with WTO provisions. In the Australia-Canada salmon case of 2000, WTO held that “Australia was not in violation of Art. 5.5, as it found that although Australia was employing different levels of protection to different, but sufficiently comparable situations, the different treatment was scientifically justified, and not arbitrary or unjustifiable and the different treatment was thus not a disguised restriction on international trade.”

Second, India can use the logic of compliance with sovereign laws of the land. In the Argentina-Brazil poultry anti-dumping case of 2003, WTO ruled: “Argentina was not in violation of Art. 6.8 when it disregarded information submitted by a company that had not fulfilled procedural provisions of the domestic law...as information submitted by such companies was not considered appropriately submitted”. Since Taiwan manufactures many items that China produces, we must exponentially increase India’s diplomatic, economic and technological relations with it: Our trade has travelled from $66 million to $6 billion.

Benjamin Disraeli said, “What we call public opinion is generally public sentiment.” Never has any Indian government after 1962 got greater anti-China bipartisan support than now. We need only to lose our self-imposed chains. Chanakya can trump Confucius: “Do not reveal what you have thought upon doing, but by wise council keep it secret being determined to carry it into execution...Once you start working on something, don’t be afraid of failure and don’t abandon it.”

Abhishek Singhvi is former chairman, Parliamentary Standing Committee; former Additional Solicitor General, senior national spokesperson, Congress and an eminent jurist

The views expressed are personal

The consistently-married group was slightly higher in well-being at the end of life than the consistently-single and varied histories groups; the latter two groups did not differ in their well-being

Loved and lost or never loved at all? Lifelong marital histories and their links with subjective well-being. Mariah F. Purol ,Victor N. Keller, Jeewon Oh, William J. Chopik & Richard E. Lucas. The Journal of Positive Psychology, Jul 7 2020. https://doi.org/10.1080/17439760.2020.1791946

ABSTRACT: Marriage has been linked to higher well-being. However, previous research has generally examined marital status at one point in time or over a relatively short window of time. In order to determine if different marital histories have unique impacts on well-being in later life, we conducted a marital sequence analysis of 7,532 participants from the Panel Study of Income Dynamics (54.2% women; Mage  = 66.68, SD = 8.50; 68.7% White/Caucasian). Three different marital sequence types emerged: a ‘consistently-married’ group (79%), a ‘consistently-single’ group (8%), and a ‘varied histories’ group (13%), in which individuals had moved in and out of various relationships throughout life. The consistently-married group was slightly higher in well-being at the end of life than the consistently-single and varied histories groups; the latter two groups did not differ in their well-being. The results are discussed in the context of why marriage is linked to well-being across the lifespan.

KEYWORDS: Sequence analysis, lifespan approach, marital history, subjective well-being, life satisfaction

Positive self-evaluation is a fundamental human need; there is an overpowering effect of self-enhancement motivation in directing individuals’ attention & behavior relative to other self-evaluation motives

Anseel, Frederik, and Elena Martinescu. 2020. “Praise from a Self-enhancement Perspective: More, I Want More?.” PsyArXiv. July 9. doi:10.4324/9780429327667

Abstract: Positive self-evaluation is a fundamental human need, enabling individuals to face challenges or pursue new opportunities in their environment. In the past decades, several lines of research have provided support for the overpowering effect of self-enhancement motivation in directing individuals’ attention and behavior relative to other self-evaluation motives. In the current chapter, we briefly summarize the basics of self-enhancement theory, how it has helped understand the psychology of praise and how some long-standing theoretical debates have been solved. In the second part, we review new theoretical issues that have emerged in recent years, summarize new manifestations of self-enhancement in the study of praise and 'real-world' applications of these insights.

Requisite Skills and the Meaningful Measurement of Cognition Among the Lowly Educated or Non-Medicated Schizophrenics

Requisite Skills and the Meaningful Measurement of Cognition. Richard S. E. Keefe, Michael F. Green, Philip D. Harvey. JAMA Psychiatry. Published online July 8, 2020. doi:10.1001/jamapsychiatry.2020.1618

In 1931, the noted neuropsychologist Alexander Luria, along with his supervisor Lev Vygotsky, led an expedition from Moscow to Uzbekistan with an honorable objective: to understand cognition in a population with low educational levels.1 However, they concluded that the minimal educational background of the population could prevent these individuals from engaging in the basic elements of a cognitive evaluation and that existing cognitive tests were not valid for their study population, so they created specialized tests that would be more appropriate. The study by Stone et al2 shares features of this expedition 90 years ago. Some of our era’s leading scientists have conducted an equally honorable collaborative project in the rural province of Ningxia, China, to assess individuals with chronic schizophrenia who have never received antipsychotic medications. By examining this population, the authors aimed to address the problem of the exclusion of underserved individuals from research on serious mental illness and to examine the longitudinal cognitive trajectory of schizophrenia in its natural untreated condition. The authors found that, in their cross-sectional sample, the duration of untreated psychosis was associated with worse cognitive performance. They specifically reported the association between cognition and the duration of chronic untreated psychosis as having partial Spearman correlation coefficients of 0.35 for the Brief Assessment of Cognition in Schizophrenia, Symbol Coding subtest; 0.24 for the Neuropsychological Assessment Battery, Mazes subtest; and 0.02 for the Brief Visuospatial Memory Test–Revised. These 3 assessments are conceptualized in western cultures as tests of processing speed, reasoning and problem solving, and visual memory. As with the findings of Luria and Vygotsky, given the distinct population in the Stone et al2 study, it is important to consider whether the assessments were suitable to the investigators’ purpose. The most relevant considerations are the validity of the tests for this group of individuals with low educational levels and the consequences of factors that could be associated with the passage of time itself, such as aging and changes in educational quality and opportunity.

To assess cognition in this study sample, the authors chose the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognition Battery (MCCB), which has been used to understand cognitive treatment response in clinical trials of cognition among patients with schizophrenia3 and has been accepted as a criterion-standard measure by the US Food and Drug Administration. The MCCB has been translated into more than 20 languages and has demonstrated reliability and validity in a wide variety of populations with schizophrenia across the world. Stone et al2 properly used a culturally adapted version of the MCCB that had been validated and normed in China and compared the results of participants with chronic untreated schizophrenia with those of a cohort of individuals without mental illness who had similar ages and educational histories. However, as described in standards published by the American Psychological Association,4 one of the important assumptions when administering tests such as the MCCB is that all participants have sufficient experience with the basic elements of testing to understand the intent of the test and perform the test procedures. Based on the educational level of the participants in this study, it is likely that these assumptions were not met, and the study’s primary findings may be associated with changes in education over time.

Any cross-sectional study of the association between longitudinal variables and cognition must recognize that performance on static tests of cognitive ability has been reported to improve (approximately 0.2 SDs per decade) over subsequent generations.5 There are many possible reasons for this improvement, which is called the Flynn effect6; these reasons include improvements in education, knowledge, health, nutrition, poverty, and environmental stimulation, among others.7 While the Flynn effect may be reversing in some western countries,6 it can be substantial in a rapidly evolving culture such as China, especially in the midst of an educational revolution. The median educational level of the participants in the Stone et al2 study was 3 years, and the median age of the participants was 52 years, with a range of 19 to 81 years. The study participants attended school between 1942 and 2004. Over the course of those 62 years, 2 rapid advances in education occurred that outpaced population growth. During the first period, from 1957 to 1960, the number of primary students attending school increased from 55 million to more than 90 million, and the number of middle school students doubled; during the second period, from 1966 to 1976, the number of middle school students increased from less than 15 million to more than 65 million.8 These increases in educational availability and quality were likely even more substantial in underdeveloped regions like Ningxia. Thus, given that the disease onset for most individuals with schizophrenia occurs during a narrow window in late adolescence, the older participants in this study would have been raised in a less advanced educational system. Early education focuses on the basic tenets of reading, writing, and arithmetic. Testing people who lack these fundamental skills creates challenges for the evaluation of cognition.

How, specifically, does the absence of relevant experience create challenges for the validity of a cognitive assessment battery? As an obvious example, consider a processing speed test with quickly moving stimuli that requires respondents to type letters on a smart phone. If test performance were compared between an individual aged 80 years who had no experience with the technology and an individual aged 25 years who had 15 years of experience with the technology, performance differences would likely be associated with the respondent’s experience with that technology, which was substantially different. Few, if any, investigators would consider the test results a valid measure of the participants’ cognition.

To those who received education in societies in which advanced education is the norm, a pencil would not be considered an advanced technology; however, those with limited experience in the use of a pencil will likely have difficulty completing tests that require drawing figures from memory or writing numbers quickly, and such adept use of a pencil is required for 4 of the 10 tests in the MCCB. Previous research on performance-based tests in China reported that, with regard to test performance, the consequences of low educational level were greater than those of a schizophrenia diagnosis, and the most difficult task for test respondents was writing their names using a pencil.9 Measuring the association between the duration of illness and cognition in a cross-sectional study is problematic when older participants have limited experience with the tools required for performance.

Revising the traditional instructions of a test by including additional practice trials and explanations, as done in the Stone et al2 study, may be insufficient. Just as children who are not exposed to human voices during early developmental periods are likely to struggle with language through adulthood, children who do not master fundamental skills, such as writing, during early education are likely to have the remainder of their lives shaped by the absence of those skills, and they may never be able to acquire the skill levels of those who received the requisite training.

The results of the Stone et al2 study illustrate the importance of requisite skills for cognitive assessment. The tests that were associated with duration of illness shared a common feature: all 3 of them required the use of a pencil. Only 1 of the 7 tests that were not associated with illness duration involved pencil use. Those tests mostly involved verbal interaction, which is, of course, a part of everyday life among people with lower and higher educational levels alike, so formal education for that skill was not necessary.

Leading anthropologists have asserted that the neuroanatomy and cognitive capacity of humans as a species have not changed in 30 000 years.10 However, our methods for assessing cognitive ability have changed substantially based on the extent and quality of the education we have received, which has allowed us to perform well on those same assessments, and methods will continue to change as the technologies we use to perform assessments advance. Conducting studies of cognition among people, near and far, who live in regions with underdeveloped educational systems is an important endeavor, but these studies may require special considerations for assessment and the development of specific tests that allow measurement of cognition that is independent of the confounding factor of inexperience with the requisite tools. Cognitive assessments may otherwise remain confounded by variability because of cultural advantages that provide early experience with the requisite tools for only a portion of the population.

From 2015... Reductionist evidence in science debate by laypersons is viewed as more explanatory & conclusive than comparable evidence from macrolevel processes; the preference for reductionist information does not go away with education

From 2015... The Influence of Reductionist Information on Perceptions of Scientific Validity. Rebecca Rhodes. PhD Thesis, Michigan Univ., Psychology, 2015. https://deepblue.lib.umich.edu/bitstream/handle/2027.42/111352/rerhodes_1.pdf?sequence=1&isAllowed=y

ABSTRACT
The ability to reason scientifically about evidence is an important skill for many everyday decisions, ranging from whom to choose in the next presidential election to whether or not to immunize your child. Evidence for the importance of scientific reasoning can be found in continued attempts to improve the teaching of reasoning skills within the educational system. However, in order to develop effective strategies for reasoning about scientific evidence, it is important to understand lay conceptions about what it means for something to be “scientific”. In the present work, I examine the influence that reductionist evidence – that is, evidence that comes from micro-level processes, such as biological or neurological processes – has on perceptions of scientific validity. Across eight experiments, I demonstrate that reductionist evidence tends to be viewed as more explanatory and more conclusive than comparable evidence from macrolevel processes, such as psychological processes. Interestingly, the preference for reductionist information does not go away with education. In fact, people with greater scientific literacy are even more likely to assume that reductionist information is superior to macro-level information. I interpret this finding as evidence that the preference for reductionist information is not irrational, but instead an expected consequence of traditional science curricula. I demonstrate several important implications of reductionist preference. For example, this preference increases the likelihood of making causal inferences from the results of research studies that suggest micro-level – as opposed to macro-level – mechanisms, and it can decrease the size of the sample one needs to feel confident in accepting conclusions from these studies. I relate these findings to current pervasive issues in the scientific community, such as publication biases and the prevalence of underpowered studies utilizing reductionist approaches. I also discuss educational strategies that could encourage holistic thinking about science – specifically, emphasizing science as a tool for thinking strategically about everyday phenomena, regardless of the level of analysis, rather than a collection of discrete facts obtained by the use of technology and equipment.

Blame Crime on Name? People with Bad Names Are More Likely to Commit Crime in Continental China

Bao, Han-Wu-Shuang, Jianxiong Wang, and Huajian Cai. 2020. “Blame Crime on Name? People with Bad Names Are More Likely to Commit Crime.” PsyArXiv. July 9. doi:10.31234/osf.io/txhqg

Abstract: Prior evidence has revealed the interpersonal and intrapersonal costs of bearing “bad” names. The current research examined whether bad names predicted a more serious social outcome: criminal behavior. We found name-crime links based on a large dataset of 981,289 Chinese criminals (as compared to the whole Chinese population and a national representative sample of 1,000,000 non-criminal controls). People whose names were unpopular, negative, or implied lower warmth/morality were more likely to commit property and violent crime, whereas people whose names implied higher competence/assertiveness were more likely to commit violent and economic crime. Critically, lower warmth/morality of name still robustly predicted crime when controlling for demographic confounds and addressing alternative explanations. Furthermore, possessing a less warm/moral name predicted the motive for intentionally committing crime. These findings demonstrate the ethical costs of bearing bad/immoral names and enrich the understanding of how social-cognitive dimensions (warmth–competence) are associated with human behavior.


          “As his name is, so is he; Nabal is his name, and folly is with him.”
                            —Bible (1 Samuel 25:25)

Bad names may invite trouble. As the Bible says, people with a “bad” name may also possess a “bad” trait. Substantial evidence has revealed that bearing a bad (e.g., unpopular, undesirable) name predicted worse interpersonal outcomes (e.g., being unfavorably treated by others; Gebauer, Leary, & Neberich, 2012) and worse intrapersonal outcomes (e.g., poorer mental health; Twenge & Manis, 1998). Some preliminary evidence has even shown that juveniles with a less popular name have a higher tendency toward delinquent or problematic (Kalist & Lee, 2009). In this research, we focused on a possible link between bad names and criminal behavior—a more serious social outcome that hazards both other people and the whole society. Specifically, we investigated the name-crime links comprehensively across seven categories of crime and four dimensions of name. Examining the name-crime links will uncover the ethical costs of bearing bad names beyond its well-documented costs on interpersonal and intrapersonal outcomes.

Baboons (Papio anubis) living in larger social groups have bigger brains

Baboons (Papio anubis) living in larger social groups have bigger brains. Adrien Meguerditchian et al. Evolution and Human Behavior, Jul 9 2020. https://doi.org/10.1016/j.evolhumbehav.2020.06.010

Abstract: The evolutionary origin of Primates' exceptionally large brains is still highly debated. Two competing explanations have received much support: the ecological hypothesis and the social brain hypothesis (SBH). We tested the validity of the SBH in (n = 82) baboons (Papio anubis) belonging to the same research centre but housed in groups with size ranging from 2 to 63 individuals. We found that baboons living in larger social groups had larger brains. This effect was driven mainly by white matter volume and to a lesser extent by grey matter volume but not by the cerebrospinal fluid. In comparison, the size of the enclosure, an ecological variable, had no such effect. In contrast to the current re-emphasis on potential ecological drivers of primate brain evolution, the present study provides renewed support for the social brain hypothesis and suggests that the social brain plastically responds to group size. Many factors may well influence brain size, yet accumulating evidence demonstrates that the complexity of social life is an important determinant of brain size in primates.

Keywords: Social brainGroup sizeBrain sizeBaboon

Helping was facilitated in rats that had previously observed other rats’ helping and were then tested individually; the influence of bystanders on helping behavior in rats seems close to human helping

The bystander effect in rats. View ORCID ProfileJohn L. Havlik et al. Science Advances Jul 8 2020:Vol. 6, no. 28, eabb4205. DOI: 10.1126/sciadv.abb4205

Abstract: To investigate whether the classic bystander effect is unique to humans, the effect of bystanders on rat helping was studied. In the presence of rats rendered incompetent to help through pharmacological treatment, rats were less likely to help due to a reduction in reinforcement rather than to a lack of initial interest. Only incompetent helpers of a strain familiar to the helper rat exerted a detrimental effect on helping; rats helped at near control levels in the presence of incompetent helpers from an unfamiliar strain. Duos and trios of potential helper rats helped at superadditive rates, demonstrating that rats act nonindependently with helping facilitated by the presence of competent-to-help bystanders. Furthermore, helping was facilitated in rats that had previously observed other rats’ helping and were then tested individually. In sum, the influence of bystanders on helping behavior in rats features characteristics that closely resemble those observed in humans.

DISCUSSION

Here, we demonstrate bidirectional effects of bystanders on rat helping. The effect of rat bystanders depends on their capacity to help, with helping antagonized by incompetent helpers and facilitated by additional potential helpers. Recent evidence that naïve human bystanders facilitate or, at the very least, have no negative effect upon helping (9, 15) suggests that human helping may also be bidirectional.

Two incompetent helper rats antagonized helping more than did one. Similarly, helping is progressively more suppressed as the number of human bystanders increases (3). Another similarity between the rat and human versions of the bystander effect is that subjects are only influenced by bystanders of the same in-group (16). These similarities raise the possibility that similar circuits support the classic bystander effect in rats and humans. If this is the case, then either rats have greater cognitive and cultural capacities than currently appreciated or human helping operates independently of rational reasoning and cultural influences. Evidence that the building blocks for helping are fundamental circuits involved in parental care and affiliative interactions are shared across mammals (17) supports the latter possibility.

Incompetent helpers did not prevent or retard the initiation of helping. The first day of opening was the same for rats tested with one additional rat and for control rats and was even earlier for rats tested with two additional rats. It is likely that additional rats, regardless of their competency to help, hasten the initiation of opening by socially buffering potential helpers. Social buffering refers to the improved recovery from stressors afforded by the presence of conspecifics (18, 19). Of particular relevance here, conspecifics reduce the autonomic and behavioral expression of anxiety in response to novel environments (18). In the trapped rat paradigm, social buffering likely reduces the stress of the testing conditions, facilitating proximity to the centrally located restrainer door and thereby increasing opportunities for door-opening. After the first door-opening, however, social buffering can no longer account for the disparate effects on opening elicited by the presence of additional rats of different types. Additional rats that are incompetent to help exert a negative effect on reinforcement, whereas those that are potential helpers appear to facilitate reinforcement, as revealed by the reduction in helping shown by rats tested alone following group testing.

The show of indifference by incompetent helper rats is distinct from, and far more detrimental to, motivating helping than the absence of additional rats in control conditions. In groups, bystanders influence a rat’s interpretation of his own behavior, whereas, when solo, a rat’s own internal assessment of his actions rules. For a rat that has only experienced solo testing, this assessment is enough. Yet, when solo testing follows group testing, the self-reward pales in comparison to the recalled group reinforcement. It is possible then that just as rats tested solo after having the group experience failed to reinforce their behavior, rats tested solo following testing with incompetent helpers may show a positive rebound in reinforcement and helping.

The influence of bystanders promotes conformity, the matching of one’s behavior to that of a group. Conformity need not be limited to helping. Rats who did not eat an unpalatable food when alone ate it in the presence of a “demonstrator rat” who was eating the unpalatable food (20). Thus, the effect of bystanders may be more inclusively imagined as one that promotes conformity in all manner of observable behaviors.

It was alleged that neuroscience evidence bring bias because of its over-persuasiveness for people without neuroscience training; but in severe criminal cases, neuroscientific evidence is not more persuasive than behavioral one

Yin, Ji-Xing, Yuepei Xu, and Chuan-Peng Hu. 2020. “Neuroscience Evidence Is Not More Persuasive Than Behavioral Evidence for Both Adults and Juveniles: A Preregistered Study.” PsyArXiv. July 8. doi:10.31234/osf.io/bqprd

Abstract: In last two decades, developmental neuroscience results had been cited in high-profile legal cases in the United States and other countries. However, it’s unknown whether neuroscience evidence bring bias because of its over-persuasiveness for people without training in neuroscience. Previous studies suggested that neuroscience results were over-persuasive, this effect was termed as “neuroscience bias,” but the evidence was not conclusive because of failed replication attempts. Moreover, few studies directly examined the effect developmental neuroscience in juvenile cases. To address this issue, we conducted two mock jury studies with a three (evidence type: behavioral evidence, neuroscience evidence without brain images, and neuroscience evidence with brain images) by two (offenders’ age: juvenile vs. adult) between-subject design. In a pilot study (n = 94) and pre-registered study (n = 324), participants first read a vignette, which described an offender murdered a victim and his lawyer introduced scientific evidence when defending for the offender. Participants were required to make a series of judgments, including death penalty and criminal responsibility of defendant. The results revealed a main effect for offenders’ age, but no effect for evidence type or interaction between evidence type and offenders’ age. An exploratory conditional random forest analysis again revealed that evidence type was not important in predicting participants’ judgment. Instead, other self-reported variables are more important, such as the “just deserts” view of criminal punishment and the perceived possibility the offender would re-enter society. These results suggest that, in the severe criminal cases, the neuroscientific evidence is not more persuasive than behavioral evidence, regardless the neuroscientific results are from adults or juveniles.

Noninvasive acoustic manipulation of objects in a living pigs using a phased array: These beams were shown to levitate & steer solid objects (3-mm-diameter glass spheres) along preprogrammed paths

Noninvasive acoustic manipulation of objects in a living body. Mohamed A. Ghanem, Adam D. Maxwell, Yak-Nam Wang, Bryan W. Cunitz, Vera A. Khokhlova, Oleg A. Sapozhnikov, and  View ORCID ProfileMichael R. Bailey. Proceedings of the National Academy of Sciences, July 6, 2020. https://doi.org/10.1073/pnas.2001779117

Significance: The significance of this work is the development of a technique and technology to use a steerable beam from one source to safely lift and reposition a stone in a living body. The work has direct application to expelling kidney stones or manipulating an ingestible camera. Our work provides a framework for other medical applications, as well as nonmedical uses that require noninvasively moving sizable, dense objects in a free field or within a container.

Abstract: In certain medical applications, transmitting an ultrasound beam through the skin to manipulate a solid object within the human body would be beneficial. Such applications include, for example, controlling an ingestible camera or expelling a kidney stone. In this paper, ultrasound beams of specific shapes were designed by numerical modeling and produced using a phased array. These beams were shown to levitate and electronically steer solid objects (3-mm-diameter glass spheres), along preprogrammed paths, in a water bath, and in the urinary bladders of live pigs. Deviation from the intended path was on average <10%. No injury was found on the bladder wall or intervening tissue.

Keywords: acoustic tweezersacoustic radiation forcekidney stones

Why chimpanzees carry dead infants: an empirical assessment of existing hypotheses

Why chimpanzees carry dead infants: an empirical assessment of existing hypotheses. Elizabeth V. Lonsdorf, Michael L. Wilson, Emily Boehm, Josephine Delaney-Soesman, Tessa Grebey, Carson Murray, Kaitlin Wellens and Anne E. Pusey. Royal Society Open Science, July 1 2020. https://doi.org/10.1098/rsos.200931

Abstract: The study of non-human primate thanatology has expanded dramatically in recent years as scientists seek to understand the evolutionary roots of human death concepts and practices. However, observations of how conspecifics respond to dead individuals are rare and highly variable. Mothers of several species of primate have been reported to carry and continue to interact with dead infants. Such interactions have been proposed to be related to maternal condition, attachment, environmental conditions or reflect a lack of awareness that the infant has died. Here, we tested these hypotheses using a dataset of cases of infant corpse carrying by chimpanzees in Gombe National Park, Tanzania (n = 33), the largest dataset of such cases in chimpanzees. We found that mothers carried infant corpses at high rates, despite behavioural evidence that they recognize that death has occurred. Median duration of carriage was 1.83 days (interquartile range = 1.03–3.59). Using an information theoretic approach, we found no support for any of the leading hypotheses for duration of continued carriage. We interpret these data in the context of recent discussions regarding what non-human primates understand about death.

4. Discussion

In this contribution, we presented the largest systematic and quantitative study of variation in infant corpse carrying in wild chimpanzees. We found that chimpanzees carry infant corpses at high rates, despite behavioural evidence that they recognize that death has occurred. Moreover, none of the variables we examined to test existing hypotheses for the duration of ICC were significant.

Recent discussions surrounding the phenomenon of infant corpse carrying have recommended reporting the rate of corpse carrying [18] and what factors contribute to variability in rates [16]. We found that in every recorded case in which a mother was able to access her infant's body, she carried it. The only exceptions to this pattern were when the infant was killed by infanticide and the mother never regained access, and when an infant corpse was recovered in the field and the mother was not seen (with or without the corpse) in the interim. It is possible that the disappearances represented cases in which infants were not carried, but given that we cannot see every chimpanzee every day, it is also possible that they were all carried. Even if we assume that all of the 41 individuals that disappeared were not carried, and include the two cases in which corpses were recovered without ever being seen with their mother, the carrying rate would be 50/93 or 54%. What is clear is that rate of carrying we report here, between 54% and 100%, is substantially higher than that reported in Japanese macaques in which 15% of all corpses are carried and 28.7% of very young infants (less than or equal to 30 days old) are carried [18]. However, complete information regarding what happened to macaque infants that were not carried (i.e. whether corpses were observed but abandoned immediately or whether the infant simply disappeared/was subject to predation, etc.) was not reported. Such information would allow us to more fully understand the differences in carrying rates we report here. Comparable rate data are not yet available for other primate populations, and should be a focus of ongoing data collection.

We documented 33 cases of dead infant carrying, ranging in length from 30 min to over 15 days. On average, infant corpses were carried for a little over 3 days, and only two were seen to be carried over 10 days. Both of these carriers resumed cycling and mating while still carrying the corpse. In 24% of instances, the primary carrier was a non-mother but there was no difference in the duration of carriage between mothers and non-mothers. Interestingly, one of the relatively prolonged cases was performed by a non-mother who abducted a live infant and then carried it after it died. The mean carrying duration we found for Gombe was shorter than previously reported for wild chimpanzees. A recent meta-analysis of cases in anthropoid primates [17] reported a mean duration for chimpanzees of 32.94 days, as well as the largest within-species variance among the other species examined, from 2 to 114 days. These authors included only chimpanzee cases extracted from previously published reports (n = 9), so it is possible that the published literature is biased towards extremely long cases. However, a compilation of 14 cases from Mahale [27] also reports a larger range of durations, from 30 min to approximately 126 days. An interesting possibility is that there may be site-specific cultural differences in responses to death [2,21] as there are with several other behaviours [51]. Alternatively, differences in ranging patterns may affect duration of carriage such that larger day ranges constrain duration of carriage, as suggested by Carter et al. [52] for chacma baboons (Papio ursinus).

Several proximate explanations have been put forth to explain either the likelihood or duration of ICC. We examined infant age at death to test the post-parturient condition hypothesis and the maternal-bond strength hypothesis, but none of our candidate models that contained infant age at death provided a better fit to our data than the null model (table 3). Moreover, we documented several instances of carrying by non-mothers as well as two cases of prolonged carrying in which the carriers resumed cycling and mating while still carrying the corpse (as also seen in geladas [23]). The only notable age-related pattern we found was that no infants over 3 years of age were observed being carried. However, there were only nine individuals between the ages of 3 and 5 years of age in the full dataset, five of which disappeared (see electronic supplementary material, table S2). Of the remaining four, one was orphaned, one was killed by chimpanzees, one was killed by humans, and one died of illness. Thus, only the infant that died of illness could have been carried, but there were 6 days between sightings of this mother with and without the infant, so carrying cannot be determined. One possibility is that at 3 years of age, which is when most offspring cease riding on their mothers [50], corpses are simply too heavy and/or awkward to be carried for lengthy periods of time. A similar age effect was reported in Japanese macaques, in which carrying rates increased with age up until 30 days, but then decreased [18]. In sum, the small number of deaths above age three and the uncertainty around them prevent determination of whether there is an upper age limit for an infant to be carried, but the combined evidence does not support the post-parturient condition hypothesis of infant carrying. Bond strength probably plays a role in who carries a corpse given that mothers, adoptive mothers and siblings exhibited the most carrying (table 4), but it does not appear to predict duration of carriage in a consistent way.

The slow decomposition hypothesis [23] posits that prolonged infant carrying is facilitated by dry climates and/or in the dry parts of the year. According to our model comparison, the model including season was the second-highest-weighted model (table 3), although this model performed no better than the null model. In fact, while our two longest cases (table 2) occurred during the dry season, carrying duration tended to be longer in the wet season (though this parameter estimate included 0 in the 95% CI). Cases of prolonged carrying at Bossou occurred during the dry season [21], but prolonged carries in Mahale happened throughout the year [27]. In sum, we found no clear support for the hypothesis that carrying duration varied according to within-site environmental conditions.

The unawareness of death hypothesis concerns what mothers may or may not understand about death [24,25]. One prediction arising from this hypothesis is that younger and/or first-time mothers carry dead infants for longer in order to gather more information and be certain the infant is dead. None of our candidate models that included either firstborn status or mother's age at death performed significantly better than the null model. In fact, aside from one outlier (APb1), mothers tended to carry firstborn offspring for shorter durations than later born offspring (though this parameter estimate included 0 in the 95% CI). Given that we only have nine firstborn offspring in the dataset of observed corpses, more cases are needed to confirm this pattern. In the above-mentioned anthropoid primate meta-analysis [17], younger females exhibited shorter durations of carrying (regardless of firstborn status) in contrast to prediction. However, because datasets from across 18 different species were combined, mother's age was partitioned into two categories, younger versus older (according to median life span for the species). That difference in methodology, coupled with the smaller sample of nine chimpanzees in that study, may account for our different findings. These authors also found that infants that died of sickness or were stillborn were carried for longer than those that died of infanticide or unnatural causes (such as electrocution) and suggested that more violent/obvious causes of death resulted in faster detection of death and abandonment of corpses. By contrast, we found that candidate models including cause of death provided no better fit than the null model.

Our examination of the specific types of behaviour directed at the corpse suggests that mothers/primary carriers rapidly recognized a change of state in the infant, given that atypical carrying postures were exhibited soon after death. In fact, these postures more closely resembled those used for objects than live infants [53,54] and would be uncomfortable or harmful for a live infant, suggesting that mothers persisted in infant corpse carrying for hours or days after recognizing a change in state. There are also multiple sensory death cues: failure to respond to tactile stimulation, olfactory cues of putrefaction, and the presence of flies. While we do not have consistent quantitative measures of distance for our cases, observers often described a process in which the mother gradually increased her distance from the corpse, as was reported in [29]. As the post-mortem period progressed, siblings and others were permitted to interact with the corpse in a manner similar to object play, or roughly handle the corpse. In very rare cases, mothers exhibited rough handling or ate parts of the corpse themselves. These qualitative reports and our model comparison results do not support the unawareness of death hypothesis.

With regards to the broader question of whether there is evidence of a human-like death concept in chimpanzees, our data provide additional evidence that chimpanzees understand at least two of the four subcomponents reviewed in [2]: non-functionality, given the changes in behaviour described above, and irreversibility, given the eventual abandonment of the corpse. Whether or not chimpanzees understand death as universal is not possible to examine with our data, and indeed, is difficult to explore without a common language. The causality component is the last to be acquired by human children and its importance is debated given its reliance on knowledge of biological processes that have only come about through modern science and medicine (A Gonçalves 2019, personal communication). Das et al. [17] argued that anthropoid primates comprehend causality, because infants that died of unnatural and externally observable causes were carried for shorter periods than those that died of natural causes. However, we did not find that cause of death explained the variation in duration of infant carrying in our larger, single-species sample.

Evaluating our findings according to the three-level model of death awareness proposed by Gonçalves & Carvahlo [3], our data provide support for the first two and suggest that chimpanzees quickly distinguish between animate and inanimate and also integrate sensory and contextual cues to discriminate between living and dead. The third level of death awareness encompasses the four subcomponents of a human-like death concept described above, and we have provided additional evidence in accordance with [2] for chimpanzees' understanding of non-functionality and irreversibility. Evidence for the subcomponents of universality and causality will probably need to come from rigorous and ethical cognitive experiments conducted in captive settings [19].

Given that we found no evidence for the main existing hypotheses for ICC, the question remains as to why chimpanzee mothers, if they have distinguished between alive and dead, continue to carry their infant corpses for multiple days after death and often exhibit caretaking behaviours such as grooming. This behaviour could be interpreted as lack of awareness that death has occurred, but the behavioural changes we described above suggest otherwise. An intriguing possibility is that infant corpse carrying represents a primate analogue of human grief [17,55]. However, grief has been difficult to systematically define and operationalize; even in humans, grief is recognized as a ‘highly individualized and dynamic process’ [56, p. 119]. Evidence in non-verbal animals must come from behaviour, and an increasing number of species have been reported to exhibit behaviours similar to humans. These include prolonged association with the corpse [8,57–59], decreased appetite [12,17,57,60], and social isolation and/or avoidance [17,22,57]. How non-human animal emotions are defined, measured and whether they differ in degree or kind from human emotions is an active area of scientific debate (see [61,62]). Responses to death may be a particularly fruitful area of focus for the study of primate emotions.

Much work remains to be done to achieve a more complete understanding of non-human animal responses to death. We echo the calls of our colleagues [3,16] for more detailed descriptions of cases using standardized terminology and variables, and collection of physiological data such as stress metabolites. Detailed analyses of changes in maternal activities budgets, such as reduced feeding and socializing, as well as others' consolation behaviours towards mothers, will help to provide a more complete picture of a species' understanding of death. These data are extraordinarily difficult to collect and accumulate given the rarity of observed deaths in the wild, which highlights the importance of long-term studies for understanding of the complexity of animal behaviour. While many questions remain, observations reported here and elsewhere challenge Heidegger's [1] assertion that ‘Animals cannot do this'.

Rolf Degen summarizes: Psychopaths have more social ties to others who have no contact with each other, which may give them greater potential to manipulate

Are Psychopathic Traits Associated with Core Social Networks? An Exploratory Study in University Students. Kylie S. Reale et al. Social Psychology Quarterly, July 7, 2020. https://doi.org/10.1177/0190272520902105

Abstract: In a sample of 480 university students, we examined associations between self-ratings of psychopathic traits, made using the Comprehensive Assessment of Psychopathic Personality (CAPP), the Psychopathic Personality Inventory: Short Form (PPI: SF), and self-ratings of the structure of their core social networks (i.e., best friends, intimates). Results indicated that higher self-ratings of domains (CAPP) and subscales (PPI: SF) related to interpersonal dominance, manipulation, poor attachment, and emotional regulation were associated with less connected core networks. We interpret the dominance and manipulation domain and subscale findings as preliminary evidence of a deliberate strategy to provide a more influential position within one’s social network. As for the associations with the attachment and emotional regulation domain and subscale findings, we suggest this could be reflective of deficits or a lack of desire both in establishing and maintaining long-term relationships.

Keywords: CAPP, interpersonal relationships, PPI, SNA, social networks

Intranasal Oxytocin (InOT): Tested interactive InOT effects were highly heterogeneous; for most published interactions, no replication was attempted; when attempted, replications were largely unsuccessful

How Can Intranasal Oxytocin Research Be Trusted? A Systematic Review of the Interactive Effects of Intranasal Oxytocin on Psychosocial Outcomes. A. Mierop et al. Perspectives on Psychological Science, July 7, 2020. https://doi.org/10.1177/1745691620921525

Abstract: Over the past two decades, research about the role of oxytocin (OT) in human behavior has grown exponentially. However, a unified theory of OT effects has yet to be developed. Relatedly, growing concerns about the robustness of conclusions drawn in the field have been raised. The current article contributes to this debate by reporting on and discussing key conclusions from a systematic review of published studies addressing the interactive effects of intranasal OT (IN-OT) administration on psychosocial outcomes in a healthy population. The review indicates that (a) tested interactive IN-OT effects were highly heterogeneous; (b) for most published interactions, no replication was attempted; (c) when attempted, replications were largely unsuccessful; (d) significance was unrelated to sample size; (e) statistical power was critically low and unrelated to the rate of significant results; and (f) research practices were characteristic of an exploratory approach. This concerning state of affairs makes it virtually impossible to tease apart true from false interactive IN-OT effects. We provide constructive directions on the basis of this observation and positive predictive value simulations for future research that should help extract true effects from noise and move the IN-OT field forward.

Keywords: neuroendocrinology, oxytocin, social cognition, positive predictive value