Group longevity as a function of its size in agricultural societies -- groups of 50, 150 and 500 people are near optimal

Optimising human community sizes. R.I.M. Dunbar, R. Sosis. Evolution and Human Behavior, https://doi.org/10.1016/j.evolhumbehav.2017.11.001

Abstract: We examine community longevity as a function of group size in three historical, small scale agricultural samples. Community sizes of 50, 150 and 500 are disproportionately more common than other sizes; they also have greater longevity. These values mirror the natural layerings in hunter-gatherer societies and contemporary personal networks. In addition, a religious ideology seems to play an important role in allowing larger communities to maintain greater cohesion for longer than a strictly secular ideology does. The differences in optimal community size may reflect the demands of different ecologies, economies and social contexts, but, as yet, we have no explanation as to why these numbers seem to function socially so much more effectively than other values.

Keywords: Small scale societies; Fractal layering; Hutterites; C19th utopian communities; Kibbutz

“There was 100% better treatment as a wife under Boko Haram. There was more gifts, better food, and a lot of sex that I always enjoyed.”

Rescued and deradicalised women are returning to Boko Haram. Why? By Hilary Matfess
http://africanarguments.org/2017/11/01/rescued-and-deradicalised-women-are-returning-to-boko-haram-why/
Girls and women who join Boko Haram simply tend to see it as the best option available to them.
African Arguments, November 1, 2017

[Photo: It is not uncommon to hear of girls and women escaping IDP camps to return to their Boko Haram husbands. Credit: UD.]

This June, reports emerged that Aisha, the wife of Boko Haram commander, had fled her home in Maiduguri. The 25-year-old reportedly escaped the city to rejoin her husband Mamman Nur and other insurgents in the Sambisa Forest.

Stories of girls and young women leaving camps for internally-displaced persons to return to the notoriously brutal Boko Haram are not uncommon in north-eastern Nigeria. But Aisha’s story is particularly troubling. She had only recently completed a targeted, nine-month long deradicalisation programme.

If Aisha returned to Boko Haram despite all the resources dedicated to her deradicalisation and rehabilitation, what does the future hold for the scores of other women who receive significantly less support?


Why women join Boko Haram

The roughly 70-person deradicalisation programme in which Aisha participated was a mixture of psychosocial support and religious education. The provision of care to women who have been traumatised is certainly valuable, but the framing of this support as a deradicalisation programme mischaracterises the motivations of women who join Boko Haram.

In my conversations with women who joined the Islamist militant group of their own volition, many cite the opportunities that being a member of the insurgency provides. Aisha, who benefitted particularly thanks to her husband’s senior role as a commander, told Reuters in February that she was given slaves who “washed, cooked, and babysat for her”. “Even the men respected me because I was Mamman Nur’s wife,” she boasted.

However, even women who were not wives of elite fighters reported that joining the group conveyed tangible benefits. One woman I spoke to said: “There was 100% better treatment as a wife under Boko Haram. There was more gifts, better food, and a lot of sex that I always enjoyed.”

Another girl who married into the insurgency told me she particularly enjoyed the sect’s mandatory, near-daily Quranic education. “I was happy because I was meeting with my friends and getting learning,” she said, contrasting this with her much more intermittent access to schooling outside the group.

As detailed in my new book Women and the War on Boko Haram, women also often joined the insurgency because of the material improvement it can bring. Many women said they were drawn to Boko Haram because brideprices are paid directly to women rather than their family and because purdah – the practice of wife seclusion that’s associated with the socio-economic elite in northern Nigeria – is practiced widely.

These benefits contrast with typical experiences outside the insurgency. Only 4% of girls in northern Nigeria complete secondary school, while a UK government report estimates that 80% of women in eight northern states are unable to read. Early marriage is prevalent, access to health care is meagre, and the maternal mortality rate in the region is five times the global average.


Coming home

Women who are rescued or removed from Boko Haram return to the material deprivation and socio-political marginalisation that drove them to the group in the first place. But in addition, they may also come to face new forms of discrimination.

According to Dr Fatima Akilu, founder of the Neem Foundation, which provides psychosocial support, women who return home face the “possibility of violence”. Women may successfully go through the deradicalisation programme, she says, but then struggle in the community because of intense stigmatisation.

This accounts for both women who joined Boko Haram voluntarily and those abducted against their will. A UNICEF and International Alert report found that some community leaders are reticent to accept abducted women back into the community as “their ideas and ways of life may now be different and may not be good for the community”.

Despite widespread recognition of the problems of reintegration, there has yet to be a broad, community-oriented sensitisation programme to help girls return home. Furthermore, deradicalisation programmes generally do not focus on the sorts of livelihood development or skills acquisition that could help these single women support themselves and their children.

This mistrust and economic insecurity puts women who return at high risk of exploitation and gender-based violence.

[Full text and reference information in the link above]
Hilary Matfess’ book Women and the War on Boko Haram Wives, Weapons, Witnesses is out on 3 November 2017.

The scientific practices of experimental psychologists have improved dramatically

Psychology's Renaissance. Leif D. Nelson, Joseph P. Simmons, and Uri Simonsohn. Annual Review of Psychology, forthcoming. https://doi.org/10.1146/annurev-psych-122216-011836

Abstract: In 2010–2012, a few largely coincidental events led experimental psychologists to realize that their approach to collecting, analyzing, and reporting data made it too easy to publish false-positive findings. This sparked a period of methodological reflection that we review here and call Psychology’s Renaissance. We begin by describing how psychologists’ concerns with publication bias shifted from worrying about file-drawered studies to worrying about p-hacked analyses. We then review the methodological changes that psychologists have proposed and, in some cases, embraced. In describing how the renaissance has unfolded, we attempt to describe different points of view fairly but not neutrally, so as to identify the most promising paths forward. In so doing, we champion disclosure and preregistration, express skepticism about most statistical solutions to publication bias, take positions on the analysis and interpretation of replication failures, and contend that meta-analytical thinking increases the prevalence of false positives. Our general thesis is that the scientific practices of experimental psychologists have improved dramatically.

Keywords: p-hacking, publication bias, renaissance, methodology, false positives, preregistration

---
Psychologists have long been aware of two seemingly contradictory problems with the published literature. On the one hand, the overwhelming majority of published findings are statistically significant (Fanelli 2012, Greenwald 1975, Sterling 1959). On the other hand, the overwhelming majority of published studies are underpowered and, thus, theoretically unlikely to obtain results that are statistically significant (Chase & Chase 1976, Cohen 1962, Sedlmeier & Gigerenzer 1989). The sample sizes of experiments meant that most studies should have been failing, but the published record suggested almost uniform success.

There is an old, popular, and simple explanation for this paradox. Experiments that work are sent to a journal, whereas experiments that fail are sent to the file drawer (Rosenthal 1979). We believe that this “file-drawer explanation” is incorrect. Most failed studies are not missing. They are published in our journals, masquerading as successes.

The file-drawer explanation becomes transparently implausible once its assumptions are made explicit. It assumes that researchers conduct a study and perform one (predetermined) statistical analysis. If the analysis is significant, then they publish it. If it is not significant, then the researcher gives up and starts over. This is not a realistic depiction of researcher behavior. Researchers would not so quickly give up on their chances for publication, nor would they abandon the beliefs that led them to run the study, just because the first analysis they ran was not statistically significant. They would instead explore the data further, examining, for example, whether outliers were interfering with the effect, whether the effect was significant within a subset of participants or trials, or whether it emerged when the dependent variable was coded differently. Pre-2011 researchers did occasionally file-drawer a study, although they did not do so when the study failed, but rather when p-hacking did. Thus, whereas our file drawers are sprinkled with failed studies that we did not publish, they are overflowing with failed analyses of the studies that we did publish.

Masturbation to Orgasm Stimulates the Release of the Endocannabinoid 2-Arachidonoylglycerol

Fuss J, Bindila L, Wiedemann K, et al. Masturbation to Orgasm Stimulates the Release of the Endocannabinoid 2-Arachidonoylglycerol in Humans. J Sex Med 2017;14:1372–1379. https://doi.org/10.1016/j.jsxm.2017.09.016

Abstract

Background: Endocannabinoids are critical for rewarding behaviors such as eating, physical exercise, and social interaction. The role of endocannabinoids in mammalian sexual behavior has been suggested because of the influence of cannabinoid receptor agonists and antagonists on rodent sexual activity. However, the involvement of endocannabinoids in human sexual behavior has not been studied.

Aim: To investigate plasma endocannabinoid levels before and after masturbation in healthy male and female volunteers.

Outcomes: Plasma levels of the endocannabinoids 2-arachidonoylglycerol (2-AG), anandamide, the endocannabinoid-like lipids oleoyl ethanolamide and palmitoyl ethanolamide, arachidonic acid, and cortisol before and after masturbation to orgasm.

Methods: In study 1, endocannabinoid and cortisol levels were measured before and after masturbation to orgasm. In study 2, masturbation to orgasm was compared with a control condition using a single-blinded, randomized, 2-session crossover design.

Results: In study 1, masturbation to orgasm significantly increased plasma levels of the endocannabinoid 2-AG, whereas anandamide, oleoyl ethanolamide, palmitoyl ethanolamide, arachidonic acid, and cortisol levels were not altered. In study 2, only masturbation to orgasm, not the control condition, led to a significant increase in 2-AG levels. Interestingly, we also found a significant increase of oleoyl ethanolamide after masturbation to orgasm in study 2.

Clinical Translation: Endocannabinoids might play an important role in the sexual response cycle, leading to possible implications for the understanding and treatment of sexual dysfunctions.

Strengths and Limitations: We found an increase of 2-AG through masturbation to orgasm in 2 studies including a single-blinded randomized design. The exact role of endocannabinoid release as part of the sexual response cycle and the biological significance of the finding should be studied further. Cannabis and other drug use and the attainment of orgasm were self-reported in the present study.

Conclusion: Our data indicate that the endocannabinoid 2-AG is involved in the human sexual response cycle and we hypothesize that 2-AG release plays a role in the rewarding consequences of sexual arousal and orgasm.

Key Words: 2-Arachidonoylglycerol (2-AG); Anandamide (AEA); Oleoyl Ethanolamide (OEA); Masturbation; Orgasm; Sexuality; Reward; Cortisol

Adolescents with autism spectrum disorder exhibited more accurate metaperceptions than did typically developing adolescents

Metaperception in Adolescents With and Without Autism Spectrum Disorder. Lauren V. Usher et al. Journal of Autism and Developmental Disorders, https://link.springer.com/article/10.1007/s10803-017-3356-1

Abstract: This study compared how adolescents with and without autism spectrum disorder (ASD) evaluated unfamiliar peers (i.e., perceptions), as well as how adolescents believed they were evaluated by peers (i.e., metaperceptions). The Perceptions and Metaperceptions Questionnaire was designed to quantify perceptions and metaperceptions following a live interaction. For all adolescents, more positive perceptions of the peer were associated with more positive metaperceptions. Adolescents with ASD exhibited more accurate metaperceptions than did typically developing adolescents. More positive perceptions and metaperceptions were associated with higher levels of observed social competence across groups. Findings extend our understanding of typically and atypically developing adolescents’ impressions of unfamiliar peers and their ability to discern what peers think of them.

Across the first year, most infants have approximately 2.5 times more social interactions with women than men

Differential Trajectories in the Development of Attractiveness Biases Toward Female and Male Targets. Jennifer L. Rennels and Kirsty M. Kulhanek. In "Perception of Beauty", book edited by Martha Peaslee Levine, ISBN 978-953-51-3582-1, Print ISBN 978-953-51-3581-4, Published: October 25, 2017 under CC BY 3.0 license.  DOI: 10.5772/intechopen.69342

Abstract: Across the first year, most infants have approximately 2.5 times more social interactions with women than men. There is evidence that because of this differential experience, infants develop a cognitive representation for human faces that is weighted toward female-like and attractive. Subsequently, attractiveness is more salient when infants process female relative to male faces. These early asymmetries in facial experience and the greater saliency of attractiveness for female and male targets persist into early childhood, which contributes to attractiveness influencing children’s categorization and judgments of females more strongly than for males. During middle childhood, children’s facial representations become more differentiated, which might explain increases in children’s attractiveness biases for male targets during this developmental period. By adolescence, mating interests seem to combine with these developing facial representations to influence attractiveness preferences. This chapter reviews asymmetries in the saliency of attractiveness for female and male targets from infancy to adolescence and focuses on how cognitive facial representations likely guide how attractiveness influences children’s processing of female and male targets.

Keywords: development, face processing, attractiveness bias, sex differences, stereotyped attitudes

Has the rising placebo response impacted antidepressant clinical trial outcome? Data from the US FDA 1987‐2013

Has the rising placebo response impacted antidepressant clinical trial outcome? Data from the US Food and Drug Administration 1987‐2013. Arif Khan et al. World Psychiatry. 2017 September 21; 16(3): 328. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5428172/

Abstract: More than fifteen years ago, it was noted that the failure rate of antidepressant clinical trials was high, and such negative outcomes were thought to be related to the increasing magnitude of placebo response. However, there is considerable debate regarding this phenomenon and its relationship to outcomes in more recent antidepressant clinical trials. To investigate this, we accessed the US Food and Drug Administration (FDA) reviews for sixteen antidepressants (85 trials, 115 trial arms, 23,109 patients) approved between 1987 and 2013. We calculated the magnitude of placebo and antidepressant responses, antidepressant‐placebo differences, as well as the effect sizes and success rates, and compared these measures over time. Exploratory analysis investigated potential changes in trial design and conduct over time. As expected, the magnitude of placebo response has steadily grown in the past 30 years, increasing since 2000 by 6.4% (r=0.46, p less than 0.001). Contrary to expectations, a similar increase has occurred in the magnitude of antidepressant response (6.0%, r=0.37, p less than 0.001). Thus, the effect sizes (0.30 vs. 0.29, p=0.42) and the magnitude of antidepressant‐placebo differences (10.5% vs. 10.3%, p=0.37) have remained statistically equivalent. Furthermore, the frequency of positive trial arms has gone up in the past 15 years (from 47.8% to 63.8%), but this difference in frequency has not reached statistical significance. Trial design features that were previously associated with a possible lower magnitude of placebo response were not implemented, and their relationship to the magnitude of placebo response could not be replicated. Of the 34 recent trials, two implemented enhanced interview techniques, but both of them were unsuccessful. The results of this study suggest that the relationship between the magnitude of placebo response and the outcome of antidepressant clinical trials is weak at best. These data further indicate that antidepressant‐placebo differences are about the same for all of the sixteen antidepressants approved by the FDA in the past thirty years.

Keywords: Antidepressants, clinical trials, placebo response, antidepressant‐placebo difference, effect size, success rate, enhanced interview techniques

The Impact of Variation in Twin Relatedness on Estimates of Heritability and Environmental Influences

The Impact of Variation in Twin Relatedness on Estimates of Heritability and Environmental Influences. Chang Liu, Peter C. M. Molenaar, and Jenae M. Neiderhiser. Behavior Genetics, https://link.springer.com/article/10.1007/s10519-017-9875-x

Abstract: By taking advantage of the natural variation in genetic relatedness among identical (monozygotic: MZ) and fraternal (dizygotic: DZ) twins, twin studies are able to estimate genetic and environmental contributions to complex human behaviors. Recently concerns have been raised about the accuracy of twin studies in light of findings of genetic and epigenetic changes in twins. One of the concerns raised is that MZ twins are not 100% genetically and epigenetically similar because they show variations in their genomes and epigenomes leading to inaccurate estimates of heritability. This article presents findings from a simulation study that examined the degree of bias in estimates of heritability and environmentality when the genetic and epigenetic similarity of MZ twins differs from 1.00 and when the genetic and epigenetic similarity of DZ twins differs from 0.50. The findings suggest that in the standard biometric model when MZ or DZ twin similarity differs from 1.00 or 0.50, respectively, the variance that should be attributed to genetic influences is instead attributed to nonshared environmental influences, thus deflating the estimates of genetic influences and inflating the estimates of nonshared environmental influences. Although estimates of genetic and nonshared environmental influences from the standard biometric model were found to deviate from “true” values, the bias was usually smaller than 10% points indicating that the interpretations of findings from previous twin studies are mostly correct.

Sex Differences in the Prevalence and Correlates of Handgun Carrying Among Adolescents in the USA

Sex Differences in the Prevalence and Correlates of Handgun Carrying Among Adolescents in the United States. Michael G. Vaughn et al. Youth Violence and Juvenile Justice, https://doi.org/10.1177/1541204017739072

Abstract: Handgun carrying is associated with a wide range of delinquent behaviors, but very little is known about sex differences in this behavior and current trends in handgun carrying in the United States. Using data from the 2002 to 2015 National Study of Drug Use and Health surveys, we found that the prevalence of handgun carrying among girls nearly doubled from 0.9% to 1.7% with most of this increase seen among non-Hispanic White and Hispanic girls. Although boys are more likely to carry handguns, approximately 20% of the total handgun carrying by adolescents in the United States occurs among girls. Both male and female adolescents who have carried a handgun in the past year evince a behavioral profile that is characterized by substance use, versatile delinquency, elevated risk propensity, and substantial school and family problems. However, adjusted odds ratios are consistently higher for females, suggesting that girls who engage in handgun carrying represent an important subgroup of potentially pernicious offenders that should be targeted for primary and tertiary prevention and juvenile justice system oversight.

Evidence of the Effect of Confirmation-Reports on Dishonesty

Duncan, D. and Li, D. (2017), Liar Liar: Experimental Evidence of the Effect of Confirmation-Reports on Dishonesty. Southern Economic Journal. doi:10.1002/soej.12244

Abstract: We identify the effect of confirmation-reports on dishonesty using data from an experiment where subjects are asked to roll a die and report its outcome using either a self-report or confirmation-report mechanism. We find that relative to self-reports, confirmation-reports have a positive effect on the share of subjects who report honestly. The effect on the magnitude of lies told depends greatly on the accuracy of the prefilled information on the confirmation-report. We argue that these results are driven by changes in the intrinsic costs of lying induced by the confirmation report.

---
Obviously, men lie more than women in both conditions.

Prenatal androgens apparently have large effects on interests and engagement in gendered activities; moderate effects on spatial abilities; and relatively small or no effects on gender identity, gender cognitions, and gendered peer involvement

Berenbaum, S. A. (2017), Beyond Pink and Blue: The Complexity of Early Androgen Effects on Gender Development. Child Dev Perspect. doi:10.1111/cdep.12261

Abstract: Why do girls and women differ from boys and men? Gender development is typically considered to result from socialization, but sex hormones present during sensitive periods of development, particularly prenatal androgens, play an important role. Data from natural experiments, especially from females with congenital adrenal hyperplasia, show the complexity of the effects of androgens on behavior: Prenatal androgens apparently have large effects on interests and engagement in gendered activities; moderate effects on spatial abilities; and relatively small or no effects on gender identity, gender cognitions, and gendered peer involvement. These differential effects provide an opportunity to move beyond identifying sources of variation in behavior to understanding developmental processes. These processes include links among gendered characteristics, psychological and neural mechanisms underlying development, and the joint effects of biological predispositions and social experiences.

People are reluctant to be dishonest to interaction partners with dilating pupils, which are perceived positively

Pupil to pupil: The effect of a partner's pupil size on (dis)honest behavior. Jolien A. van Breen, Carsten K.W. De Dreu, Mariska E. Kret. Journal of Experimental Social Psychology, Volume 74, January 2018, Pages 231–245. https://doi.org/10.1016/j.jesp.2017.09.009

Highlights
•    People are reluctant to be dishonest to interaction partners with dilating pupils.
•    Findings suggest that partners with dilating pupils are perceived more positively, resulting in more pro-social treatment.
•    The pro-social effects of dilating pupils were most evident in competitive contexts.
•    Pupil mimicry was restricted to non-competitive contexts.
•    The effect of observed pupil dilation on dishonesty does not rely on the occurrence of pupil mimicry between partners.

Abstract: Being observed by others fosters honest behavior. In this study, we examine a very subtle eye signal that may affect participants' tendency to behave honestly: observed pupil size. For this, we use an experimental task that is known to evoke dishonest behavior. Specifically, participants made private predictions for a coin toss and earned a bonus by reporting correct predictions. Before reporting the (in)correctness of their predictions, participants viewed videos of partners with dilating or constricting pupils. As dilating pupils are generally perceived positively, we expected that dishonesty would be reduced when participants look into the eyes of a partner with dilating pupils, especially when their own pupil size mimics the observed pupil size. In line with this prediction, Experiments 1 and 2 showed that, when earning a bonus meant harming the interaction partner, dishonesty occurred less frequently when the partner's pupils dilated rather than constricted. That is, when the interests of the self and the other conflict, participants use the pupil of the partner as a social cue to inform their behavior. However, pupil mimicry was not observed. In Experiment 3, we examined pupil mimicry and dishonesty in a context where there was no temptation to hurt the partner. Here, pupil mimicry between partners was observed, but there were no effects of the partner's pupil on dishonesty. Thus, when dishonesty harms the interaction partner, participants use pupillary cues from their partner to inform their behavior. Pupil mimicry, however, is bound to non-competitive contexts only.

Keywords: Pupil size; Pupil mimicry; Dishonesty; Interpersonal interaction; Competition

Mate choice could be random in female rats (Rattus norvegicus)

Mate choice could be random in female rats (Rattus norvegicus). Olivia Le Moëne, Eelke M. Snoeren. Physiology & Behavior, https://doi.org/10.1016/j.physbeh.2017.10.031

Highlights
•    Female rats prefer the male visited first in a multiple partners paradigm.
•    This mate selection is not based on the male rats, but on the location of the male.
•    It suggests that mate choice in female rats is random.

Abstract: Female mate choice is often investigated in terms of reproductive success in order to understand how male characteristics contribute to sexual attractiveness. Previous studies have found that females rats prefer mating with their first encounter rather than males visited subsequently, suggesting that the rewarding value of this first encounter is enough to reinforce mating with the first partner. Using a multiple chambers paradigm, we allowed female rats to copulate freely with three males placed each in a different chamber. Then, we switched the males' position, and let the female interact with them freely again within the same session. We tested whether female mate choice was relying rather on a preferred male rat or on a preferred mating location. The results showed that females spent most time with the male in the chamber of 1st entry in the beginning, but as soon as male rats switched chambers, the female rat continued to copulate with the new male in the same chamber of 1st entry, instead of mating with her previously preferred male rat. This suggests that the male preference is an artefact of location preference. Therefore, female mate choice seems to be rather random than the consequence of an individual choice based on male characteristics. This finding, although contradictory with the intuitive feeling that mate choice is a crucial feature in sexual and reproductive behavior, is supported by several recent observations. In the coming years, behavioral neuroscience should bring light to the brain processes at work in random mate choice.

Keywords: Female rats; Multiple partner; Sexual behavior; Mate choice; Location

---
The procedures were similar to those previously described [1]. At the start of the experiment, a (sexually experienced, hormonally primed) female rat was placed in the
middle chamber of the multiple chambers set-up. The subject was allowed to move freely and habituate to the chambers for 5 minutes. Then, for another 5 minutes, the female was placed in the middle chamber, while three (sexually experienced) male rats were positioned in the three surrounding small chambers. During this time, the openings were blocked with a wire mesh allowing the female subject to see, smell and hear the male rats without any possibility of physical contact (habituation phase). The number of times the female rat sniffed the opening of each of the male chambers was determined, as an indicator of olfactory preference [10, 11].

After the habituation phase, the openings were unblocked and the female rat was allowed to move freely between the chambers for another 15 minutes (copulation phase A). During this period, the following behaviors were scored for each male: order in which the males were visited, latency to first visit, number of visits, time spent in the chambers, number of sniff episodes to the openings of the chambers, and the number of mounts, intromissions and ejaculations per male. In addition, the number of paracopulatory behaviors the female performed in the chamber of each male were counted.

After the copulation phase A, the male rats were quickly randomly placed in a different chamber and the test continued for another 15 minutes (copulation phase B). During this period, the same parameters were scored as during copulation phase A. All sessions were conducted with chambers containing “dirty bedding” that consisted of the smell of several male and female rats. This was done to limit the (potential) effects of bedding odors after the switch.