Saturday, February 9, 2019

Is the Capacity for Vocal Learning in Vertebrates Rooted in Fish Schooling Behavior?

Is the Capacity for Vocal Learning in Vertebrates Rooted in Fish Schooling Behavior? Matz Larsson, Benjamin W. Abbott. Evolutionary Biology, December 2018, Volume 45, Issue 4, pp 359–373. https://link.springer.com/article/10.1007/s11692-018-9457-8

Abstract: The capacity to learn and reproduce vocal sounds has evolved in phylogenetically distant tetrapod lineages. Vocal learners in all these lineages express similar neural circuitry and genetic factors when perceiving, processing, and reproducing vocalization, suggesting that brain pathways for vocal learning evolved within strong constraints from a common ancestor, potentially fish. We hypothesize that the auditory-motor circuits and genes involved in entrainment have their origins in fish schooling behavior and respiratory-motor coupling. In this acoustic advantages hypothesis, aural costs and benefits played a key role in shaping a wide variety of traits, which could readily be exapted for entrainment and vocal learning, including social grouping, group movement, and respiratory-motor coupling. Specifically, incidental sounds of locomotion and respiration (ISLR) may have reinforced synchronization by communicating important spatial and temporal information between school-members and extending windows of silence to improve situational awareness. This process would be mutually reinforcing. Neurons in the telencephalon, which were initially involved in linking ISLR with forelimbs, could have switched functions to serve vocal machinery (e.g. mouth, beak, tongue, larynx, syrinx). While previous vocal learning hypotheses invoke transmission of neurons from visual tasks (gestures) to the auditory channel, this hypothesis involves the auditory channel from the onset. Acoustic benefits of locomotor-respiratory coordination in fish may have selected for genetic factors and brain circuitry capable of synchronizing respiratory and limb movements, predisposing tetrapod lines to synchronized movement, vocalization, and vocal learning. We discuss how the capacity to entrain is manifest in fish, amphibians, birds, and mammals, and propose predictions to test our acoustic advantages hypothesis.

Monozygotic Twins Seem To Have Higher Genetic Quality (significantly more physically attractive & healthier) than DZ Twins and Singletons; MZ twins may be a quality-maximizing feature of sexual reproduction

Do Monozygotic Twins Have Higher Genetic Quality than Dizygotic Twins and Singletons? Hints from Attractiveness Ratings and Self-Reported Health. Satoshi Kanazawa, Nancy L. Segal. Evolutionary Biology, https://link.springer.com/article/10.1007/s11692-019-09470-0

Abstract: Evolutionary theories generally concur that sexual reproduction and genetic recombination evolved to maximize genetic variability. Thus, the existence of monozygotic (MZ) twins, which do not take advantage of genetic recombination for each offspring, poses a puzzle. Evolutionary logic of inclusive fitness suggests that parents with high-quality genes may be more likely to produce MZ twins. Analyses of data from the National Longitudinal Study of Adolescent to Adult Health show that MZ twins were significantly more physically attractive and healthier than dizygotic (DZ) twins and singletons. These results suggest that MZ twins may possess higher-quality genes than DZ twins and singletons, and support one of the first evolutionary theories of MZ twinning that specifies its ultimate functions.

Keywords: Twin research Monozygotic twin conception Add Health

Little is known about the operation of male mate choice in systems with perceived high costs to male choosiness, like Rana sylvatica; matings with preferred females produced fewer and lower-quality offspring

Fitness costs of mating with preferred females in a scramble mating system. Lindsey Swierk, Tracy Langkilde. Behavioral Ecology, arz001, https://doi.org/10.1093/beheco/arz001

Abstract: Little is known about the operation of male mate choice in systems with perceived high costs to male choosiness. Scramble mating systems are one type of system in which male choice is often considered too costly to be selected. However, in many scramble mating systems, there are also potentially high rewards of male choosiness, as females vary dramatically in reproductive output and males typically mate once per season and/or per lifetime. Using scramble mating wood frogs (Rana sylvatica), we tested whether males gain fitness benefits by mating with preferred females. We conducted choice trials (1 male presented simultaneously with 2 females) and permitted males to mate with their preferred or nonpreferred female. Offspring of preferred and nonpreferred females were reared in the laboratory and field, and we quantified various fitness-relevant parameters, including survivorship and growth rates. Across multiple parameters measured, matings with preferred females produced fewer and lower-quality offspring than did those with nonpreferred females. Our results are inconsistent with the idea that mate choice confers benefits on the choosing sex. We instead propose that, in scramble systems, males will be more likely to amplex females that are easier to capture, which may correlate with lower quality but increases male likelihood of successfully mating. Such male choice may not favor increased fitness when the operational sex ratio is less biased toward males in scramble mating systems but is, instead, a bet-hedging tactic benefitting males when available females are limited.

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Our data suggest that an untested parameter of male wood frog mate choice may also play a role in determining its rela-tive costs and benefits. In recent decades, mate choice based on genetic compatibility has been demonstrated to be an important and widely observed component of mate choice (see Brown 1997; Tregenza and Wedell 2000; Mays and Hill 2004). In particular, mate choice based on dissimilarity of major histocompatibility complex (MHC) genes has been observed in humans (Wedekind et al. 1995) and other species (e.g., Gowaty et al. 2003; Agbali et al. 2010; Rymešová et al. 2017; for review see Kamiya et al. 2014); benefits of choosing a mate with dissimilar MHC genes include provisioning offspring with a greater variety of cell-surface proteins that enable the immune system to identify and fight pathogens and parasites (Bernatchez and Landry 2003; Piertney and Oliver 2006; Ruff et al. 2012). If male mate choice in wood frogs also has an MHC-compatibility component (or similar), then it could be pre-dicted that, when faced with challenges to the immune system, offspring of preferred females would have a fitness advantage over the offspring of nonpreferred females. When taken as a whole, our data support this idea. In the lab, in the absence of immune chal-lenges, offspring of preferred females had lower survivorship than the offspring of nonpreferred females (Figure 3a), possibly due to reasons associated with female catchability, as proposed above. However, in the presence of numerous immune challenges in the field, this difference in offspring survivorship disappears (Figure 4a). A MHC-related fitness cost to mating with nonpreferred mates could be responsible for closing the gap between preferred and nonpreferred offspring field survivorship. While admittedly far from conclusive, these results imply that multiple types of mate choice may exist in this scramble system and could warrant future study. 

Friday, February 8, 2019

Alext Tabarrok: First in-depth, independent evaluation of one MVP project & it doesn't look great: The project did some good but the big push failed & the good could have been done at lower cost

Barnett, C., Masset, E. Dogbe, T., Jupp, D., Korboe, D., Acharya, A., Nelson, K., Eager, R. and Hilton, T. (2018) 'Impact Evaluation of the SADA Millennium Villages Project in Northern Ghana: Endline Summary Report', Brighton: Itad in association with IDS, LSHTM and PDA Ghana. http://opendocs.ids.ac.uk/opendocs/handle/123456789/14060

Abstract: The Millennium Villages Project (MVP) aims to demonstrate how the Millennium Development Goals (MDGs) could be achieved locally through an integrated approach to development. While the MDGs have now been superseded by the Sustainable Development Goals (SDGs, 2016–30), there remains a consistent thread to the MDGs around issues such as eradicating poverty, preventing avoidable deaths and improving education. Furthermore, the interconnected nature of the SDGs means the MVP model also has relevance for those seeking to address extreme poverty by taking an integrated approach to sustainable development. This report summarises the findings from what we believe to be the first independent impact evaluation of the MVP approach. It is hoped that the evidence and analysis will be of relevance to a wide range of actors in international development.

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Comments by A Tabarrok at The Big Push Failed, Oct 16 2018, https://marginalrevolution.com/marginalrevolution/2018/10/big-push-failed.html

"The initial MVP evaluation claimed great success but simply compared some development indicators before and after in the treated villages without comparing to trends elsewhere. In 2010 such a study was completely out of step with contemporary practices in impact evaluation. Red flag! Clemens and Demombynes showed that comparing to trends elsewhere significantly moderated the impact. A second MVP paper was published in the Lancet but then was quickly retracted when Bump, Clemens, Demombynes and Haddad demonstrated that it had  significant errors. Clemens and Demombynes wrote a summary piece on the controversy then in an astounding and under-reported scandal the MVP tried to stifle Clemens and Demombynes. The MVP, with Jeff Sachs at the head, also sicced their lawyers on Nina Munk and her book, The Idealist: Jeffrey Sachs and the Quest to End Poverty. More red flags.

Yet, despite all of this controversy and bad behavior, the MVP project continued to move ahead and in 2012, the UK Department for International Development (DFID) funded US $11 million into an MVP in Northern Ghana that ran until December 2016. Under the auspices of the DFID, we now finally have the first in-depth, independent evaluation of one MVP project and it doesn’t look great. The project did some good but the big push failed and the good that was done could have been done at lower cost."

Check the post, it has lots of links.

Conservatives seem more fear-motivated, disgust-sensitive, & happy; liberals might have greater overall negative emotional biases towards politicians who are ideologically dissimilar

Contempt of Congress: Do Liberals and Conservatives Harbor Equivalent Negative Emotional Biases Towards Ideologically Congruent vs. Incongruent Politicians at the Level of Individual Emotions? Russell L. Steiger, Christine Reyna, Geoffrey Wetherell, Gabrielle Iverson. Journal of Social and Political Psychology,  Vol 7, No 1 (2019). https://jspp.psychopen.eu/article/view/822

Abstract: Prior research suggests that conservatives are more fear-motivated, disgust-sensitive, and happy than liberals. Yet when it comes to political targets (e.g., politicians), both liberals and conservatives can get very emotional. We examined whether the ideological differences in emotion seen in past research apply to emotions towards specific ideologically similar vs. dissimilar targets, or whether these emotions are instead equivalent between liberals and conservatives. Across two studies, liberals and conservatives rated their anger, contempt, disgust, fear, and happiness towards Democratic and Republican congresspersons. We compared participants’ levels of each emotion towards their respective ideologically dissimilar and ideologically similar congresspersons. Liberals and conservatives both experienced stronger negative emotions towards ideologically dissimilar congresspersons than they did towards ideologically similar ones. Neither liberals nor conservatives differed in negative emotions towards politicians overall (i.e., on average). However, there were ideological differences in emotional bias. In Study 1, liberals exhibited a greater contempt bias (i.e., a larger gap in contempt ratings between ideologically similar and ideologically dissimilar politicians) than conservatives did. In Study 2, liberals exhibited greater contempt, anger, disgust, and happiness biases than conservatives did. The need to consider context in the study of ideological differences in emotion is discussed.

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Although there are well-documented findings suggesting that conservatives are more prone to experiencing fear, disgust, and happiness than liberals are, these ideological differences in emotion did not come into play in the context of emotions towards ideologically dissimilar versus ideologically similar politicians. These findings suggest that emotions towards politicians may represent a special case that overrides these general ideological differences in emotion. Surprisingly however, our findings also indicated that liberals might have greater overall negative emotional biases towards politicians who are ideologically dissimilar, and that this difference may be especially pronounced regarding contempt. This finding may be a function of political power dynamics (greater emotional bias towards those who controlled congress at the time), or may reflect an ideological difference in emotion that has yet to be revealed—a liberal orientation towards contempt.

Mice use olfaction to asses risk in the environment from predators & food; ethanol elicited clear avoidance in laboratory mice, as fox faeces did; ethanol could be a cue for fruit ripening (over-ripe, unhealthy fruits)

Ethanol and a chemical from fox faeces modulate exploratory behaviour in laboratory mice. Carlos Grau et al. Applied Animal Behaviour Science, https://doi.org/10.1016/j.applanim.2019.02.003

Highlights
•    Mice use olfaction to asses risk in the environment from predators and food
•    Ethanol, a plant-based chemical cue elicited clear avoidance in laboratory mice
•    Fox faeces and TMT (predator stimuli) elicited avoidance with some differences to ethanol

Abstract: Mice are macrosmatic animals that use olfaction as their main source of information to increase fitness; they process predator cues to assess risk, and plants and fruit cues to find nutritional resources and assess their quality or toxicity. In this study, we examined the effects of ethanol as an olfactory stimulus related to fruit rotting, against 2,4,5-trimethylthiazoline (TMT, a fox faeces compound), its native origin, the fox faeces and a negative control on avoidance, locomotor activity, and stress related behaviour, measured by the production of faecal boli. Our results showed that mice clearly avoided ethanol (P=<0.0001) and decreased their locomotor activity (P = 0.0076) when ethanol was present. The molecule 2,4,5-trimethylthiazoline (TMT), was the most avoided (P=<0.0001) and showed the lowest locomotor activity (P = 0.0004). Both treatments, ethanol (P = 0.0348) and TMT (P = 0.0084) increased the number of faecal boli.

The clear avoidance and behavioural effects of ethanol in mice have direct implications in laboratory animal research, where it is used widely. This avoidance effect could elicit stressful situations and modify behavioural and physiological responses in mice housed in research facilities. In addition, this avoidance could be used as a non-lethal, inexpensive and non-toxic tool in rodent pest management. To explain these results, we suggest ethanol as a probable cue for fruit ripening, in the wild, this chemical cue could convey primordial information about the ripening state of fruits, allowing animals to avoid over-ripe, unhealthy fruits.

But check, from 2012: Sexual Deprivation Increases Ethanol Intake in Drosophila. G. Shohat-Ophir et al. Science Mar 16 2012: Vol. 335, Issue 6074, pp. 1351-1355. https://www.bipartisanalliance.com/2019/02/sexual-deprivation-increases-ethanol.html

In this, we are closer to a fly than to a mouse...

Anxious attachment (hypervigilant detection of and reactivity to social inconsistency and unreliability) heightens pattern deviancy (distortions of repeated forms or models) aversion, contributing to prejudice

Anxious Attachment as an Antecedent of People's Aversion Towards Pattern Deviancy. Anton Gollwitzer, Margaret S. Clark. European Journal of Social Psychology, Dec 2018, https://doi.org/10.1002/ejsp.2565

Abstract: Research suggests that people's aversion towards pattern deviancy – distortions of repeated forms or models – contributes to social phenomena, such as prejudice. Yet, the factors motivating pattern deviancy aversion remain unclear. Potentially, anxious attachment, as it entails hypervigilant detection of and reactivity to social inconsistency and unreliability, heightens pattern deviancy aversion. In Studies 1 (N = 137) and 2 (N = 102), anxious but not avoidant attachment predicted aversion towards broken patterns of geometric shapes. In Studies 3 (N = 310) and 4 (N = 470), experimentally inducing anxious versus avoidant and secure attachment (Study 3), and versus a neutral prime (Study 4), heightened pattern deviancy aversion. Controlling for participants’ aversion towards unbroken patterns, novel objects, and negative stimuli did not change these results. Our findings demonstrate that anxious attachment is one antecedent of pattern deviancy aversion, and suggest that pattern deviancy aversion may underlie links between anxious attachment and certain social phenomena.

Anxious Attachment as an Antecedent of Pattern Deviancy Aversion

We hypothesize that anxious attachment may activatea domain-general response towards patterns in a per-son’s environment, specifically, in the form of an aversion towards broken patterns. In other words, wepropose that the fear of social unreliability and inconsistency entailed in anxious attachment (e.g., Bartz &Lydon, 2008) extends to a domain-general aversion towards inconsistencies. In support of this possibility, anxiously attached individuals lack a secure base from which to explore irregularities in their environment (Ainsworth et al., 1978; Bowlby, 1973). And further, some evidence suggests that anxiously attached indi-viduals seek out consistency in their surroundings outside of the social domain. For instance, anxious attachment is related to engaging in compulsive ritualsto reduce stress (American Psychiatric Association,2000; Doron, Sar-El, Mikulincer, & Talmor, 2012).In addition, shared correlates of anxious attachment and pattern deviancy aversion support our hypothesis.For instance, anxious attachment has been linked to heightened prejudice (e.g., Di Pentima & Toni, 2009; Mikulincer, 1997; Mikulincer & Shaver, 2001), andaversion towards pattern deviancy also relates to prejudice (Gollwitzer et al., 2017). Further, anxious attachment (compared to secure attachment) relatesto increased seeking of meaning in life (Bodner, Berg-man, & Cohen-Fridel, 2014), and Heintzelman et al.(2013) found participants to report a higher meaningin life after viewing patterned as opposed to random non-social stimuli. Researchers have also found participants from Asian cultures and with Asian backgrounds to exhibit higher levels of anxious attachment than those from Western cultures (e.g., Wang & Mallinckrodt, 2006; Wei, Russell, Mallinckrodt, & Zakalik, 2004), and members of East Asian cultures exhibit a greater dislike of non-social pattern deviancy than do European Americans (Gollwitzer et al., 2017; Kim & Markus, 1999). Additionally, anxious attachment is associated with neuroticism (Shaver & Brennan, 1992), a construct that is related to pattern deviancy aversion as well (Gollwitzer et al., 2017).

Finally, anxious attachment and aversion towards broken patterns both relate to heightened moral concern with regard to harm and purity violations (Gollwitzer,Martel, Bargh, & Chang, 2019; Koleva, Selterman, Iyer, Ditto, & Graham, 2014). Aside from these overlapping relationships, anxiously attached individuals fear inconsistencies and unreliability in the social domain, and these are exactly the qualities that pattern deviancy aversion captures more generally.

Whereas we expected anxious attachment to predict pattern deviancy aversion, we did not expect avoidant attachment to predict such aversion. Avoidant individuals have models of other people as unworthy of trust (Mikulincer & Shaver, 2003) and consistently act in accord with this conclusion—they simply avoid intimate social relationships (e.g., Beck & Clark, 2009). Unlike anxious attachment, avoidant attachment is neither associated with seeking reliability and consistency in close relationships, nor with fearing unreliability and inconsistency, and thus should not relate to pattern deviancy aversion.

A general aversion towards novel stimuli could potentially account for an effect of anxious attachmenton pattern deviancy aversion. Bowlby (1973) theoretically conceptualized anxious people as averse to novel stimuli, and some researchers have linked anxious attachment to an aversion towards novel, unfamiliar stimuli (Ainsworth et al., 1978; Arend, Gove, &Sroufe, 1979). Importantly, however, novel stimuli do not always break the surrounding consistencies. For instance, when novel stimuli (e.g., exotic fruits) are categorized into their own category (e.g., the category, exotic fruit; Murphy, 2004), rather than compared top revious examples, they should not be evaluated as pattern deviant. To account for novelty aversion, we included a measure of aversion towards novel stimuli that are not necessarily pattern deviant in Studies 1 through 4.

Aside from novelty aversion, we also controlled for participants’ aversion towards negative stimuli. We did so to control for the possibility that anxious attachment predicts pattern deviancy aversion simply because anxious attachment induces a general aversion towards negative stimuli (pattern deviant stimuli are generally evaluated negatively; Gollwitzer et al., 2017). Though we are unaware of any research linking anxious attachment to such negativity aversion, we wished to control for this possibility nonetheless. To do so, we included a measure of aversion towards negative but not necessarily pattern deviant stimuli in Studies 3 and 4 (aversion towards bad weather).

People tend to derogate their ideological opponents. But how does social status affect this tendency?

Taking the High Ground: The Impact of Social Status on the Derogation of Ideological Opponents. Aiden Gregg, Nikhila Mahadevan, Constantine Sedikides. Social Cognition 36(1), November 2017, DOI: 10.1521/soco.2018.36.1.43

Abstract: People tend to derogate their ideological opponents. But how does social status affect this tendency? We tested a prediction derived from hierometer theory that people with higher status would derogate ideological opponents less (i.e., evaluate them more charitably). We further predicted that greater rhetoric handling prowess (RHP: feeling more confident and less intimidated while arguing) would mediate the effect. Study 1 established a link between higher status and lesser opponent derogation correlationally. Study 2 did so experimentally. Using a scale to assess RHP developed and validated in Study 3, Study 4 established that RHP statistically mediated the correlational link between status and derogation. In Study 5, experimentally manipulating status affected RHP as predicted. However, in Study 6, experimentally manipulating RHP did not affect opponent derogation as predicted. Thus, our findings were substantially, but not entirely, consistent with our theoretically-derived predictions. Implications for hierometer theory, and related theoretical approaches, are considered.

People primarily justify eating meat using one of four rationalizations: they believe it is natural, necessary, normal, and/or nice; each of these is associated with a specific psychological profile

Psychological profiles of people who justify eating meat as natural, necessary, normal, or nice. Christopher J. Hopwood, Wiebke Bleidorn. Food Quality and Preference, https://doi.org/10.1016/j.foodqual.2019.02.004

Highlights
•    People primarily justify eating meat using one of four rationalizations: they believe it is natural, necessary, normal, and/or nice.
•    Each of these rationalizations is associated with a specific psychological profile of personality traits and values.
•    These profiles provide information about individual differences in food choice and may be used to promote behavior change.

Abstract: Research suggests that people tend to use one of four rationalizations to justify eating meat despite its empirically established negative consequences for both personal and societal well-being: the beliefs that meat is natural, necessary, normal, or nice. The goal of this study was to better understand what kind of people would tend to use these different rationalizations in terms of their personality traits, values, and motivations for plant-based eating. Results suggest specific psychological profiles for each of the four meat-eating rationalizations. These profiles may be useful for behavior change advocacy and for furthering the basic science of individual differences underlying food preferences and choices. Suggestions for future research that builds upon these initial findings are highlighted.

Check also Eating meat does not make you mean: Why vegetarians don't have the moral high ground. Rolf Degen, 2014  https://plus.google.com/101046916407340625977/posts/gaNZUm9rGW5

Thursday, February 7, 2019

Limits to Fitness Benefits of Prolonged Post-reproductive Lifespan in Women: Having a maternal grandmother improves grandchild survival, co-residence with old paternal grandmothers decreases grandchild survival

Limits to Fitness Benefits of Prolonged Post-reproductive Lifespan in Women. Simon N. Chapman et al. Current Biology, https://doi.org/10.1016/j.cub.2018.12.052

Highlights
•    Women’s hazard of death increases when grandmothering opportunities decline
•    Having a maternal grandmother improves grandchild survival
•    Co-residence with old paternal grandmothers decreases grandchild survival
•    Grandmothering favors post-reproductive longevity only up to a point

Summary: Recent advances in medicine and life-expectancy gains have fueled multidisciplinary research into the limits of human lifespan [1, 2, 3]. Ultimately, how long humans can live for may depend on selection favoring extended longevity in our evolutionary past [4]. Human females have an unusually extended post-reproductive lifespan, which has been explained by the fitness benefits provided from helping to raise grandchildren following menopause [5, 6]. However, formal tests of whether such grandmothering benefits wane with grandmother age and explain the observed length of post-reproductive lifespan are missing. This is critical for understanding prevailing selection pressures on longevity but to date has been overlooked as a possible mechanism driving the evolution of lifespan. Here, we use extensive data from pre-industrial humans to show that fitness gains from grandmothering are dependent on grandmother age, affecting selection on the length of post-reproductive lifespan. We find both opportunities and ability to help grandchildren declined with age, while the hazard of death of women increased greatly in their late 60s and 70s compared to menopausal ages, together implying waning selection on subsequent longevity. The presence of maternal grandmothers aged 50–75 increased grandchild survival after weaning, confirming the fitness advantage of post-reproductive lifespan. However, co-residence with paternal grandmothers aged 75+ was detrimental to grandchild survival, with those grandmothers close to death and presumably in poorer health particularly associated with lower grandchild survival. The age limitations of gaining inclusive fitness from grandmothering suggests that grandmothering can select for post-reproductive longevity only up to a certain point.


Preliminary support for the cuckoldry-risk hypothesis: Men pursuing a relatively slow life history strategy produced higher quality ejaculates, implying resource allocation decisions for greater parenting effort

Barbaro, N., Shackelford, T. K., Holub, A. M., Jeffery, A. J., Lopes, G. S., & Zeigler-Hill, V. (2018). Life history correlates of human (Homo sapiens) ejaculate quality. Journal of Comparative Psychology, http://dx.doi.org/10.1037/com0000161

Abstract: Life history strategies reflect resource allocation decisions, which manifest as physiological, psychological, and behavioral traits. We investigated whether human ejaculate quality is associated with indicators of relatively fast (greater resource allocation to mating effort) or slow (greater resource allocation to parenting effort) life history strategies in a test of two competing hypotheses: (a) The phenotype-linked fertility hypothesis, which predicts that men pursuing a relatively fast life history strategy will produce higher quality ejaculates, and (b) the cuckoldry-risk hypothesis, which predicts that men pursuing a relatively slow life history strategy will produce higher quality ejaculates. Men (n = 41) completed a self-report measure assessing life history strategy and provided two masturbatory ejaculate samples. Results provide preliminary support for the cuckoldry-risk hypothesis: Men pursuing a relatively slow life history strategy produced higher quality ejaculates. Ejaculate quality may therefore reflect resource allocation decisions for greater parenting effort, as opposed to greater mating effort. The findings contribute informative data on correlations between physiological and phenotypic indicators of human life history strategies.

Consciousness rests on the brain’s ability to sustain rich brain dynamics (including signal coordination) & pave the way for determining specific & generalizable fingerprints of conscious & unconscious states

Human consciousness is supported by dynamic complex patterns of brain signal coordination. A. Demertzi et al. Science Advances Feb 06 2019: Vol. 5, no. 2, eaat7603
DOI: 10.1126/sciadv.aat7603

Abstract: Adopting the framework of brain dynamics as a cornerstone of human consciousness, we determined whether dynamic signal coordination provides specific and generalizable patterns pertaining to conscious and unconscious states after brain damage. A dynamic pattern of coordinated and anticoordinated functional magnetic resonance imaging signals characterized healthy individuals and minimally conscious patients. The brains of unresponsive patients showed primarily a pattern of low interareal phase coherence mainly mediated by structural connectivity, and had smaller chances to transition between patterns. The complex pattern was further corroborated in patients with covert cognition, who could perform neuroimaging mental imagery tasks, validating this pattern’s implication in consciousness. Anesthesia increased the probability of the less complex pattern to equal levels, validating its implication in unconsciousness. Our results establish that consciousness rests on the brain’s ability to sustain rich brain dynamics and pave the way for determining specific and generalizable fingerprints of conscious and unconscious states.

Check also Chasing the Rainbow: The Non-conscious Nature of Being. David A. Oakley and Peter W. Halligan. Front. Psychol., November 14 2017. https://www.bipartisanalliance.com/2018/01/despite-compelling-subjective.html

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INTRODUCTION 
Consciousness is seemingly lost and recovered every day, from themoment we fall asleep until we wake up. Consciousness can also betransiently abolished by pharmacological agents or, more permanently,by brain injury. Each of these departures from conscious wakefulnessbrings about different changes in brain function, behavior, and neuro-chemistry. Yet, they all share a common feature: lack of reported sub-jectiveexperience(1).Finding reliable markers indicating the presence or absence of con-sciousness represents an outstanding open problem for science (2).We postulate that consciousness has specific characteristics that arebased on the temporal dynamics of ongoing brain activity and its co-ordination over distant cortical regions. Our hypothesis stems fromthe common stance of various contemporary theories which proposethat consciousness relates to a dynamic process of self-sustained,coordinated brain-scale activity assisting the tuning to a constantlyevolving environment, rather than in static descriptions of brainfunction (35). In that respect, neural signals combine, dissolve, re-configure, and recombine over time, allowing perception, emotion,and cognition to happen (6).The first biological evidence for a constantly active brain camefrom electroencephalographic recordings showing electrical oscilla-tions even when the participant was not performing any particulartask. More recently, brain dynamics have been characterized by thepresence of complex activity patterns, which cannot be completelyattributed to background noise (7). Experiments with functional mag-netic resonance imaging (fMRI) during normal wakefulness haveshown that the brain spontaneouslygenerates a dynamic series of con-stantly changing activity and connectivity between brain regions (810).This activity presents long-range temporal correlations in the sensethat signal changes exert long-term influence on future dynamics (11).This translates to a complex temporal organization of the long-rangecoupling between brain regions, with temporally correlated series oftransitions between discrete functional connectivity patterns (6). Thespatiotemporal complexity of brain dynamics contributes toward ef-ficient exchanges between neuronal populations (8), suggesting thatthe neural correlates of consciousness could be found in temporallyevolving dynamic processes, as postulated by influential theoreticalaccounts (35).In terms of states of consciousness, spontaneous fMRI dynamicconnectivity has been investigated in different sleep stages (11,12)and pharmacologically induced anesthesia in humans (13,14)andanimals (15,16). These studies indicate that, during physiologicallyreversible unconscious states, cortical long-range correlations are
disrupted in both space and time, anticorrelated cortical statesdisappear, and the dynamic explorations are limited to specific patternsthat are dominated by rigid functional configurations tied to the anatom-ical connectivity. Conversely, conscious wakefulness is characterizednot only by global integration, evidenced by strong long-distance inter-actions between brain regions, butalso by a dynamic exploration of arich and flexible repertoire of functional brain configurations departingfrom the anatomical constraints (15). Another important characteristicobserved predominantly during conscious wakefulness is the appear-ance of anticorrelations between the activity of different brain regions.This observation is in line with the prediction of the Global NeuronalWorkspace theory stating that different streams of information in thebrain compete for the global percolation (ignition) of a widespreadnetwork of regions, a phenomenon associated with conscious access.In terms of the fMRI blood oxygen leveldependent (BOLD) signal,this could manifest in the mutual inhibition of activity at different cor-tical regions, leading to anticorrelated dynamics (5).Although dynamic connectivity has been investigated in physio-logical and pharmacological unresponsiveness, currently, the altera-tions in brain connectivity dynamics associated with pathologicalunconsciousness after severe brain injury remain unknown. The studyof unresponsive brain-lesioned patients with preserved levels of vig-ilance offers unique insights into the necessary and potentially suf-ficient conditions for the capacity of sustaining conscious content. Sofar, the inference of consciousness in patients has rested on the use ofactive mental imagery neuroimaging paradigms (17) and by assess-ing the complexity of evoked (18) and spontaneous brain activity(19). Patients who successfully perform these active paradigms canno longer be considered unconscious and are thought to suffer fromcognitive-motor dissociation (20). Given that nonresponsiveness canbe associated with a variety of brain lesions, varying levels of vigilance,and covert cognition, we highlight the need to determine a commonset of features capable of accounting for the capacity to sustain con-scious experience. Given the above theoretical considerations, whichagree in the characterization of consciousness as a global, temporallyevolving process, we aimed at determining whether the dynamics ofbrain-wide coordination could provide such a set of common featuresin the form of transient patterns of connectivity that successfully gen-eralize between different forms of nonresponsiveness in patients withbrain injury.


DISCUSSION 
We studied the brains dynamic organization during consciouswakefulness and after severe brain injury leading to disorders of con-sciousness, with the aim of determining patterns of signal coordinationspecifically associated with conscious and unconscious states. Weidentified a pattern of positive and negative long-distance coordination,high modularity, with low similarity to the anatomical connectivity,
potentially relevant for the support of conscious cognition (pattern 1).We also identified a pattern of low interregional dynamic coordina-tion, low efficiency, with high similarity to anatomical connectivity,potentially specific to reduced or absent conscious processing (pattern4). With respect to pattern 1, momentary neural coalitions have beenpreviously shown to constitute a basis for complex cognitive function,with signals fluctuating between states of high and low connectivityand with more integrated states enabling faster and more accurate
performance during cognitive tasks (23). With respect to pattern 4,studies in physiological and pharmacological unconsciousnessshowed a breakdown of long-range interareal positive and negativeconnections. For example, during sleep, the presence of negative dy-namic connections disappear (11). Our results are in line with previ-ous findings in animals. As in the present study, the brain activity ofanesthetized nonhuman primates resided most frequently in a patternof low connectivity resembling the anatomy, which was sustained forlonger periods of time in comparison to more complex patterns (15).In addition, we demonstrated that network properties, such as mod-ularity, integration, distance relationship, and efficiency, increasedwith the participantsconscious state. The latter result is in line withthe hypothesis that high-efficiency patterns carry higher metaboliccosts (24), which are restricted underpathologicalunconsciousconditions (25).Our findings also align with theoretical considerations on dynamicconnectivity, suggesting that alternating patterns of correlations andanticorrelations may constitute a fundamental property of informationprocessing in the brain (26). Differentmodels of consciousness proposethat intermittent epochs of global synchronization grant segregated
and parallel network elements access to a global workspace, integratingthem serially and allowing effortful conscious cognition (27). There-fore, the transient exploration of this global workspace could permitthe brain to efficiently balance both segregated and integrated neuraldynamics and to encode globally broadcasted and therefore reportableconscious contents (3). In the absence of transient epochs of global syn-chronization, the transmission of information is expected to be rela-tively ineffective (6).With respect to patterns 2 and 3, these were not predominantlypreferred by any group in terms of occurrence probabilities and dura-tion and hence could represent transitional states (28). Pattern 3 showedthe overall positive interareal coherence. For pattern 2, the significanceof the overall negative coherence with regions of the visual networkcan only be speculated. For the moment, we suggest that it indicatesthe presence of a local coordination pattern reflecting the anatomicalorganization of the visual cortex (29).Whether the identified dynamic coordination patterns entail thepresence/absence of mental contents or cognitive function is difficultto assume without probing moment-to-moment changes in thecontents of conscious experience. Although a link has been shownbetween intrinsic connectivity networks and various behavioral tasks(30), it has been suggested that BOLD correlations need not necessar-ily reflect moment-to-moment changes in cognitive content. Instead,they may predominantly reflect processes necessary for maintainingthe stability of the brains functional organization (31). Also, the BOLDsignal is nonstationary (32), and some of its spontaneous fluctuationsmay not be a faithful reflection of functionally relevant brain dynamicsor the underlying nonstationarities of neural activity and coordination(10). We also acknowledge that the identification of these dynamicconfigurations required time-resolved analyses of fMRI time seriesin the scale of few seconds. It can be argued that conscious cognitionand the relevant features of our environment develop on a faster timescale of hundreds of milliseconds (3). However, the BOLD signal hasbeen shown to correlate with infraslow neurophysiological oscilla-tions, i.e., the slow cortical potential (33). The slow cortical potentialis important for large-scale information integration, hence suggest-ing that the flow of the conscious experience could be supported byprocesses at slower time scales (34). Future experiments should ad-dress a potential relationship between conscious experience, the slowcortical potential, and functional network reconfigurations measuredas with fMRI.Regardless of the implicated time scales, our analyses did not aim attracking the moment-to-moment contents of conscious experience,but at identifying brain-wide dynamic networks supporting differentglobal states of consciousness. We consider that the four-pattern modelcan account for modes of conscious and unconscious informationprocessing. Our interpretation is sustained by the additional testsfor the validity and replicability of the main results. We found thatthe complex dynamic pattern 1 presented low probabilities of appear-ing in patients under propofol anesthesia (whether they were commu-nicating or not at baseline) and that it was most likely to appear inpatients with covert cognition (i.e., patients in UWS who successfullyperformed mental imagery neuroimaging tasks). Both findings sug-gest its implication in conscious states. We also found that the pat-tern of low interareal coordination (pattern 4) uniformly presentedhigher probabilities of appearing in all anesthetized patients, regardlessof clinical diagnosis, and it was most likely to manifest in unresponsivepatients who did not perform the mental imagery neuroimaging task,supporting its relationship to absent or reduced conscious cognition.Pattern 4 remained visited by healthy controls even under typicalwakeful conditions. In the absence of experience sampling duringdata acquisition, the interpretation of this finding can only be specu-lative. On the one hand, it could be that healthy controls entered tran-sient microsleep states as a result of fluctuating levels of vigilance, afrequently observed phenomenon during resting-state experiments(35). Our experimental setup did not include simultaneous poly-somnography recordings to directly test this hypothesis. However,we derived different fMRI-based proxies to assess the presence ofmicrosleeps. First, we examined head movements time locked to theoccurrence of all coordination patterns and found no substantial as-sociations between the two variables, as could be expected if pattern 4was related to lapses in vigilance. Second, we performed a whole-braingeneral linear model (GLM) analysis, with the coordination patterntime series as regressors. We did not observe significant positive/negative BOLD signal changes associated with the onset of the differentcoordination patterns; in particular, the presence of coordination pat-tern 4 did not result in BOLD signal changes typical of microsleeps.Last, the likelihood of pattern 4 occurring over time did not positivelycorrelate with the elapsed scan time, as has been shown to occur forpatterns associated with lapses in vigilance (35,36). Once we rule outtransient loss of vigilance as the cause of the intrusion of pattern 4 inconscious wakefulness, we can speculate that the flow of consciouscognition may be separated by periods of absent or reduced effortfulinformation processing, as recently it was hypothesized that betweentwo successive self-reports, a subject may present states of reducedawareness (37). Behaviorally, this could take the form ofmindblanksduring which participants are not engaged in cognitivedemanding processes, although they remain vigilant (38). This inter-pretation is parsimonious with the observation that participantswere instructed to rest inside the scanner, without engaging in anyeffortful cognitive task. The potential role of transient lapses of aware-ness in the stream of conscious contents during healthy wakefulnessshould be addressed by future experiments.Together, our results suggest that, following loss of consciousness,coordinated brain activity is largely restricted to a positive pattern ofinterareal coherence dominated by the anatomical connections be-tween brain regions. In contrast, conscious states are characterizedby a higher prevalence of a complex configuration of interareal coor-dination that, while still constrained by brain anatomy, also deviatesfrom it and presents both positive and negative long-distance inter-actions. It did not escape us that such a complex interareal coor-dination pattern sporadically appeared in the group of unresponsivepatients. The real-time detection of this pattern and its reinforcementthough externally induced manipulations could represent a promis-ing avenue for the noninvasive restoration of consciousness. We con-clude that these patterns of transient brain signal coordination arecharacteristic of conscious and unconscious brain states, warrantingfuture research concerning their relationship to ongoing consciouscontent, and the possibility of modifying their prevalence by externalperturbations, both in healthy and pathological individuals, as well asacross species.

Professor Jack Ponton's New Paper: Grid Scale Electricity Storage Can’t Save Renewables

Professor Jack Ponton's New Paper: Grid Scale Electricity Storage Can’t Save Renewables. Global Warming Policy Foundation, Feb 7 2019, https://www.thegwpf.org/new-paper-grid-scale-electricity-storage-cant-save-renewables

Engineer pours cold water on battery and hydrogen technologies

A new briefing paper from the Global Warming Policy Foundation (GWPF) dismisses the idea that grid-scale electricity storage can help bring about a UK renewables revolution.

According to the paper’s author, Professor Jack Ponton, an emeritus professor of engineering from the University of Edinburgh, current approaches are either technically inadequate or commercially unviable.

Many commentators have suggested that intermittent power from wind turbines could simply be balanced with batteries or pumped hydro storage, but as Professor Ponton explains, this approach is unlikely to be viable.

“You need storage to deal with lulls in wind generation that can last for several days, so the amount required would be impracticably large. And because this would only be required intermittently, its capital cost could probably never be recovered”.

Professor Ponton also thinks that another potential saviour of the renewables revolution – hydrogen storage – has been unjustifiably hyped:

“A major problem with hydrogen is its low volumetric energy density. The only practical way of storing the large volumes required would be in underground caverns or depleted gasfields. We are already short of this type of storage for winter supplies of natural gas.”

Professor Ponton concludes that a lack of suitable storage technologies means that intermittent renewables cannot replace dispatchable coal, gas and nuclear power and so a sensible energy policy cannot be based on them.

“Wind and solar power are not available on demand and there are no technologies to make them so. Refusing to face these inconvenient facts poses a serious threat to our energy security”.

>>> Grid-Scale Storage: Can it solve the intermittency problem? https://www.thegwpf.org/content/uploads/2019/02/GridStorageWeb-1.pdf

Prevalence & correlates of medical cannabis patients' use of cannabis for recreational purposes: More than half of medical cannabis users used it recreationally, which is much more misuse than for other medications

Prevalence and correlates of medical cannabis patients' use of cannabis for recreational purposes. Meghan E.Morean, Izzy R.Lederman. Addictive Behaviors, https://doi.org/10.1016/j.addbeh.2019.02.003

Highlights
•    Patients (55.5%) legally using medical cannabis (MC) reported recreational use (RC).
•    RC use was associated with living in a state where RC is legal and being female.
•    RC use was associated with using MC to treat pain and mental health conditions.
•    RC use was associated with using MC products with high THC concentrations.
•    Using MC products with high CBD concentrations protected against RC use.

Abstract
Background: Rates of legal medical cannabis (MC) use are increasing, but little is known about the prevalence and correlates of recreational cannabis (RC) use among medical users (MC/R).

Methods: 348 MC users who resided in a state in which MC is legal and had medical authorization to use MC legally completed an anonymous survey in Spring 2017 (64.1% female, 82.8% White, mean age 33.03[±10.37] years). Rates of endorsing MC/R and the following potential correlates of MC/R were examined: the legal status of RC in participants' states of residence, sex, age, race, primary medical condition, MC product(s) used, MC expectancies, features of MC sought out (e.g., high tetrahydrocannabinol [THC] content), and negative cannabis use consequences.

Results: 55.5% of MC users engaged in MC/R. MC/R was associated with residing in a state in which RC is legal, being female, using MC for pain or mental health conditions, vaping MC concentrates, holding positive expectancies for combustible MC, and seeking out MC products with high THC concentrations. Preferring MC products with high cannabidiol (CBD) concentrations protected against MC/R.

Conclusions: More than half of MC users endorsed MC/R, which is considerably higher than rates of misuse observed for other prescription medications. Findings raise concerns about circumvention of RC laws in states where RC remains illegal and could be used to inform MC regulatory efforts (e.g., reducing THC content, increasing CBD content). Findings also suggest that prevention/intervention efforts to reduce MC/R are needed, especially among high-risk populations of MC users (e.g., women, pain patients, psychiatric patients).

Numerical cognition in honeybees enables addition and subtraction

Numerical cognition in honeybees enables addition and subtraction. Scarlett R. Howard et al. Science Advances Feb 06 2019: Vol. 5, no. 2, eaav0961. DOI: 10.1126/sciadv.aav0961

Abstract: Many animals understand numbers at a basic level for use in essential tasks such as foraging, shoaling, and resource management. However, complex arithmetic operations, such as addition and subtraction, using symbols and/or labeling have only been demonstrated in a limited number of nonhuman vertebrates. We show that honeybees, with a miniature brain, can learn to use blue and yellow as symbolic representations for addition or subtraction. In a free-flying environment, individual bees used this information to solve unfamiliar problems involving adding or subtracting one element from a group of elements. This display of numerosity requires bees to acquire long-term rules and use short-term working memory. Given that honeybees and humans are separated by over 400 million years of evolution, our findings suggest that advanced numerical cognition may be more accessible to nonhuman animals than previously suspected.

Paul Romer suggestions for the World Bank: outsource the bank’s research; for good reasons, the bank’s shareholders have chosen to protect its diplomatic function, at the expense of its research

Paul Romer, Nobel Prize in Economics, suggestions for the World Bank. https://paulromer.net/ft_oped/

First, outsource the bank’s research upon which it depends for identifying problems and proposing solutions. Diplomacy and science cannot both thrive under the same roof. One consequence of the bank’s commitment to diplomacy is its necessary embrace of the helpful ambiguity that makes it possible for multilateral institutions to allow “Chinese Taipei” compete in the Olympic Games without “Taiwan, China” having a seat in the UN. Dispassionate examination makes clear that what the bank does to maintain conformity on the diplomatic front is not compatible with scientific research.

All that matter in science are the facts. When complex political sensitivities are allowed to influence research by stifling open disagreement, it ceases to be scientific. For good reasons, the bank’s shareholders have chosen to protect its diplomatic function, at the expense of its research.

Outsourcing research would be a better, more efficient way for the bank to establish the facts needed to do its job. This would also be an investment in the universities that make the discoveries that drive human progress.

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My question: What about the IMF?

An exogenously-induced optimism engenders greater dishonesty than pessimism; dishonesty is positively correlated with self-reported optimism and mood upswings

Optimism, pessimism, mood swings and dishonest behavior. Erez Siniver, Gideon Yaniv. Journal of Economic Psychology, https://doi.org/10.1016/j.joep.2019.01.007

Highlights
•    The effects of optimism, pessimism and mood swings on dishonesty are examined.
•    An exogenously-induced optimism engenders greater dishonesty than pessimism.
•    Dishonesty is positively correlated with self-reported optimism and mood upswings.
•    Optimism in coping with a mental challenge does not trigger a sense of entitlement.

Abstract: The present paper reports the results of two experimental studies designed to examine the effects of optimism, pessimism, and mood swings on dishonest behavior. In Study 1, optimistic and pessimistic moods were exogenously induced to two classes of economics students who subsequently performed the die-under-the-cup task. Subjects experiencing an optimistic mood were found to exhibit greater dishonesty than those experiencing a pessimistic mood. In Study 2, economics students were asked, before and after taking a much-feared exam, to indicate on an optimism/pessimism mood scale how they felt about their success in it, subsequently performing the die-under-the-cup task. Dishonesty was found to be positively (negatively) correlated with post-exam optimism (pessimism) as well as with mood upswings (downswings) occurring between the post and pre-exam points of time. A side study ruled out the possibility that post-exam optimism induced a sense of entitlement which could have driven greater dishonesty.

Wednesday, February 6, 2019

Association of Fetal Growth With General and Specific Mental Health Conditions

Association of Fetal Growth With General and Specific Mental Health Conditions. Erik Pettersson, Henrik Larsson, Brian D’Onofrio, et al. JAMA Psychiatry, doi:10.1001/jamapsychiatry.2018.4342

Key Points

Question  Do the associations between fetal growth and later mental health conditions remain after controlling for familial confounding factors and psychiatric comorbidity?

Findings  This register-based study including more than 1 million participants and using a within-sibling pair design found that higher birth weight (statistically adjusted for gestational age) significantly lowered the risk for attention-deficit/hyperactivity disorder, autism, obsessive-compulsive disorder, and depression. Furthermore, an increase in birth weight by 1 kg significantly decreased a general factor of psychopathology by 0.047 SDs and a specific neurodevelopmental factor by 0.159 SDs.

Meaning  After controlling for familial factors and psychiatric comorbidity, fetal growth was most strongly associated with specific neurodevelopmental disorders.
Abstract

Importance  It is unclear if the associations between fetal growth and later mental health conditions remain after controlling for familial factors and psychiatric comorbidity.

Objective  To examine the associations between fetal growth and general and specific mental health conditions, controlling for familial factors.

Design, Setting, and Participants  This register-based study conducted in Sweden analyzed 546 894 pairs of full siblings born between January 1, 1973, and December 31, 1998. Sibling pairs were followed up through December 31, 2013. First, population-based and within-sibling pair associations (which controlled for time-invariant familial confounders) between fetal growth and the outcomes were estimated. Second, exploratory factor analysis was applied to the outcomes to derive 1 general factor and 4 specific and independent factors. Third, the general and specific factors were regressed on fetal growth. Statistical analysis was performed from March 27, 2017, to October 27, 2018.

Main Outcome and Measures  The outcomes were 11 psychiatric diagnoses (depression, anxiety, obsessive-compulsive disorder, posttraumatic stress disorder, bipolar disorder, alcohol abuse, drug use, attention-deficit/hyperactivity disorder, autism, schizophrenia, and schizoaffective disorder) and court convictions of violent crimes. Birth weight (in kilograms) statistically adjusted for gestational age was the exposure.

Results  The mean (SD) age of the 1 093 788 participants was 27.2 (6.8) years (range, 15.1-40.9 years) and 51.5% were male. Nine outcomes were significantly associated with birth weight in the population at large: depression (odds ratio [OR], 0.96; 95% CI, 0.95-0.98), anxiety (OR, 0.94; 95% CI, 0.92-0.95), posttraumatic stress disorder (OR, 0.91; 95% CI, 0.89-0.93), bipolar disorder (OR, 0.94; 95% CI, 0.89-1.00), alcohol abuse (OR, 0.89; 95% CI, 0.87-0.91), drug use (OR, 0.83; 95% CI, 0.80-0.85), violent crimes (OR, 0.85; 95% CI, 0.83-0.86), attention-deficit/hyperactivity disorder (OR, 0.88; 95% CI, 0.86-0.90), and autism (OR, 0.95; 95% CI, 0.92-0.97). Only depression (OR, 0.95; 95% CI 0.92-0.98), obsessive-compulsive disorder (OR, 0.93; 95% CI, 0.87-0.99), attention-deficit/hyperactivity disorder (OR, 0.86; 95% CI, 0.82-0.89), and autism (OR, 0.72; 95% CI, 0.69-0.76) remained significantly associated within sibling pairs. An exploratory factor analysis indicated that 1 general and 4 specific factors (capturing anxiety, externalizing, neurodevelopmental, and psychotic conditions) fit the outcomes well. Across almost all sensitivity analyses, an increase in birth weight by 1 kg significantly reduced the general (β, −0.047; 95% CI, −0.071 to −0.023) and the specific neurodevelopmental factors (β, −0.159; 95% CI, −0.190 to −0.128) within sibling pairs.

Conclusions and Relevance  Controlling for familial confounders, reduced fetal growth was associated with a small but significant increase in the general factor of psychopathology and a moderate increase in a specific neurodevelopmental factor.

A gamma-ray determination of the Universe’s star formation history

A gamma-ray determination of the Universe’s star formation history. The Fermi-LAT Collaboration. Science Nov 30 2018:Vol. 362, Issue 6418, pp. 1031-1034. DOI: 10.1126/science.aat8123

Gamma rays reveal the Universe's history

How many stars have formed in the Universe, and when did they do so? These fundamental questions are difficult to answer because there are systematic uncertainties in converting the light we observe into the total mass of stars in galaxies. The Fermi-LAT Collaboration addressed these questions by exploiting the way that gamma rays from distant blazars propagate through intergalactic space, which depends on the total amount of light emitted by all galaxies. The collaboration found that star formation peaked about 3 billion years after the Big Bang (see the Perspective by Prandini). Although this is similar to previous estimates from optical and infrared observations, the results provide valuable confirmation because they should be affected by different systematic effects.

Abstract: The light emitted by all galaxies over the history of the Universe produces the extragalactic background light (EBL) at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for gamma rays via photon-photon interactions, leaving an imprint in the spectra of distant gamma-ray sources. We measured this attenuation using 739 active galaxies and one gamma-ray burst detected by the Fermi Large Area Telescope. This allowed us to reconstruct the evolution of the EBL and determine the star formation history of the Universe over 90% of cosmic time. Our star formation history is consistent with independent measurements from galaxy surveys, peaking at redshift z ~ 2. Upper limits of the EBL at the epoch of reionization suggest a turnover in the abundance of faint galaxies at z ~ 6.

Macro‐Level Research on the Effect of Firearms Prevalence on Suicide Rates: The new analysis finds no significant effect

Macro‐Level Research on the Effect of Firearms Prevalence on Suicide Rates: A Systematic Review and New Evidence. Gary Kleck. Social Science Quarterly, https://doi.org/10.1111/ssqu.12602

Abstract
Objective: To systematically review the methods and findings of previous macro‐level research on the effect of firearms prevalence on suicide rates, and carry out a better state‐level analysis.

Methods: A cross‐sectional model of suicide rates is estimated with weighted least squares, using direct survey measures of gun prevalence.

Results and Conclusion: Prior macro‐level research is afflicted by the use of small samples of large heterogeneous units, invalid measures of gun prevalence, and few controls for confounders. The methodologically soundest prior research indicates that gun prevalence affects rates of gun suicides, but not total suicides. The new analysis likewise finds no significant effect of gun prevalence on total suicide rates.

From 2018, Sleep to be social: The critical role of sleep and memory for social interaction

Diekelmann, S., Paulus, F., & Krach, S. (2018). Sleep to be social: The critical role of sleep and memory for social interaction. Behavioral and Brain Sciences, 41, E10. doi:10.1017/S0140525X17001327

Abstract: Humans are highly social animals who critically need to remember information from social episodes in order to successfully navigate future social interactions. We propose that such episodic memories about social encounters are processed during sleep, following the learning experience, with sleep abstracting and consolidating social gist knowledge (e.g., beliefs, first impressions, or stereotypes) about others that supports relationships and interpersonal communication.