Monday, May 14, 2018

Sex differences in human brain pain pathways are present from birth: More sensitiviy in girls

The distribution of pain activity across the human neonatal brain is sex dependent. Madeleine Verriotis et al. NeuroImage,

•    Noxious stimulation causes widespread pain related potentials in the neonatal brain.
•    This widespread pain response is more likely to occur in female babies.
•    Brain responses to touch do not differ between male and female babies.
•    Sex differences in human brain pain pathways are present from birth.

Abstract: In adults, there are differences between male and female structural and functional brain connectivity, specifically for those regions involved in pain processing. This may partly explain the observed sex differences in pain sensitivity, tolerance, and inhibitory control, and in the development of chronic pain. However, it is not known if these differences exist from birth. Cortical activity in response to a painful stimulus can be observed in the human neonatal brain, but this nociceptive activity continues to develop in the postnatal period and is qualitatively different from that of adults, partly due to the considerable cortical maturation during this time. This research aimed to investigate the effects of sex and prematurity on the magnitude and spatial distribution pattern of the long-latency nociceptive event-related potential (nERP) using electroencephalography (EEG). We measured the cortical response time-locked to a clinically required heel lance in 81 neonates born between 29 and 42 weeks gestational age (median postnatal age 4 days). The results show that heel lance results in a spatially widespread nERP response in the majority of newborns. Importantly, a widespread pattern is significantly more likely to occur in females, irrespective of gestational age at birth. This effect is not observed for short latency somatosensory waveforms in the same infants, indicating that it is selective for the nociceptive component of the response. These results suggest the early onset of a greater anatomical and functional connectivity reported in the adult female brain, and indicate the presence of pain-related sex differences from birth.

Keywords: Pain; EEG; Nociception; Sex; Neonatal; Brain

Male Sexlessness is Rising, But Not for the Reasons Incels Claim

Male Sexlessness is Rising, But Not for the Reasons Incels Claim. Lyman Stone. Institute of Family Studies, May 2018.

A recent terrorist attack in Toronto, which left 10 people dead, has brought global attention to the “incel” movement, which stands for “involuntarily celibate.” The term refers to a growing number of people, particularly young men, who feel shut out of any possibility for romance, and have formed a community based around mourning their celibacy, supporting each other, and, in some cases, stoking a culture of impotent bitterness and rage at the wider world. In a few cases, this rage has spilled over in the form of terrorist attacks by “incels.” While the incels’ misogyny deserves to be called out and condemned, their ideas are unlikely to just go away. As such, the question must be posed: is the incel account of modern sexual life correct or not?

Incel communities tend to believe a few key facts about modern mating practices. First, they tend to believe women have become very sexually promiscuous over time, and indeed that virtually all women are highly promiscuous. The nickname incels use for an attractive, sexually available woman is “Stacy.” Second, they believe a small number of males dominate the market for romance, and that their dominance is growing. They call these alpha-males “Chads.” Finally, they tend to argue that the market for sex is winner-take-all, with a few “Chads” conquering all the “Stacies.” The allegedly handsome and masculine Chads are helped along by social media, Tinder, and an allegedly vacuous and appearance-focused dating scene, such that modern society gives Chads excessive amounts of sex while leaving a growing number of males with no sexual partner at all. These left out men are the incels.

This view is basically wrong. But it turns out to be wrong in an interesting and informative way.

How Much Sex Are People Having?

First of all, we may wonder about the actual trends in sexual behavior. Using data from the General Social Survey (GSS), it’s possible to estimate about how often people of different groups have sex. For this article, I will focus on individuals aged 22-35 who have never been married, and particularly males within that group.

Most groups of people age 22-35 have broadly similar amounts of sex; probably something like 60-100 sexual encounters per year. Never-married people have the least sex, about 60-80 encounters per year, while ever-married people have more sex, about 70-110 encounters per year, on average. Historically, never-married men have reported higher sexual frequency than never-married women. However, in the 2014 and 2016 GSS samples, that changed: never-married men now report slightly lower sexual frequency than never-married women. This is mostly because men are reporting less sex, not that women are reporting more sex. Female sexual frequency is essentially unchanged since 2000. In other words, a key piece of the incel story about rising female promiscuity just isn’t there.

But sexual frequency may be dominated by “Chads” and “Stacies.” What we really want to know is what share of these men and women have not had any sex. The graph below shows what share of these young men and women had not had sex at all in the last 12 months, by their sex and marital status. .

[Full text and charts at the link above.]

Putting the “Sex” into “Sexuality”: Understanding Online Pornography using an Evolutionary Framework

Putting the “Sex” into “Sexuality”: Understanding Online Pornography using an Evolutionary Framework. Catherine Salmon, Maryanne L. Fisher. EvoS Journal, 2018, NEEPS XI, pp. 1-15. -1-.

ABSTRACT: One encounters an obvious problem when using an evolutionary framework to understand online pornography. On the one hand, theories of sex specificity in mating strategies and evolved human nature lead to the prediction that there are commonalities and universals in the content people would seek in online pornography. That is, due to the fact that men have faced a distinct set of issues over the duration of human evolution, research suggests general tendencies in mate preferences, and presumably in the types of pornography that men therefore consume. Likewise, women have dealt with sex-specific challenges during human evolutionary history, resulting in patterns of mate preferences that are reflected in the types of online pornography they consume. Consequently, although the sexes likely differ in the content they prefer, there also should be a rather limited range of material that addresses male and female evolved heritages. Looking online, however, we can immediately ascertain that this limited focus is not the case, and hence, the dilemma. There is a wide range of pornographic material available online, to the extent that we are left with no option but to agree with Rule 34: "If it exists, there is porn of it." This problem demands a solution; how can there be evolved tendencies and yet such diversity in the content of online pornography? We review who the consumers of online pornography are, how frequently they consume it, and the type of content that is most commonly consumed. Our goal is to address the issue of common sexual interests and the diversity of online pornography. We discuss not just sex-specific content but also the variety of interests that are seen within online pornography and erotic literature.

KEYWORDS: Mate Preferences, Pornography, Internet, Sex Differences, Sexual Selection

A model of the dynamics of household vegetarian and vegan rates in the U.K.: A persistent vegetarian campaign has a significantly positive effect on the rate of vegan consumption

A model of the dynamics of household vegetarian and vegan rates in the U.K. James Waters. Appetite,

Abstract: Although there are many studies of determinants of vegetarianism and veganism, there have been no previous studies of how their rates in a population jointly change over time. In this paper, we present a flexible model of vegetarian and vegan dietary choices, and derive the joint dynamics of rates of consumption. We fit our model to a pseudo-panel with 23 years of U.K. household data, and find that while vegetarian rates are largely determined by current household characteristics, vegan rates are additionally influenced by their own lagged value. We solve for equilibrium rates of vegetarianism and veganism, show that rates of consumption return to their equilibrium levels following a temporary event which changes those rates, and estimate the effects of campaigns to promote non-meat diets. We find that a persistent vegetarian campaign has a significantly positive effect on the rate of vegan consumption, in answer to an active debate among vegan campaigners.

Keywords: Vegetarianism; Veganism; Food choice; Dietary change; Social influence; Animal advocacy

Strange... See this (Rolf Degen): 84 percent of all vegetarians return to meat

The Goldilocks Placebo Effect: Placebo Effects Are Stronger When People Select a Treatment from an Optimal Number of Choices

The Goldilocks Placebo Effect: Placebo Effects Are Stronger When People Select a Treatment from an Optimal Number of Choices. Rebecca J. Hafner, Mathew P. White and Simon J. Handley. The American Journal of Psychology, Vol. 131, No. 2 (Summer 2018), pp. 175-184.

Abstract: People are often more satisfied with a choice (e.g., chocolates, pens) when the number of options in the choice set is “just right” (e.g., 10–12), neither too few (e.g., 2–4) nor too many (e.g., 30–40). We investigated this “Goldilocks effect” in the context of a placebo treatment. Participants reporting nonspecific complaints (e.g., headaches) chose one of Bach's 38 Flower Essences from a choice set of 2 (low choice), 12 (optimal choice), or 38 (full choice) options to use for a 2-week period. Replicating earlier findings in the novel context of a health-related choice, participants were initially more satisfied with the essence they selected when presented with 12 versus either 2 or 38 options. More importantly, self-reported symptoms were significantly lower 2 weeks later in the optimal (12) versus nonoptimal choice conditions (2 and 38). Because there is no known active ingredient in Bach's Flower Essences, we refer to this as the Goldilocks placebo effect. Supporting a counterfactual thinking account of the Goldilocks effect, and despite significantly fewer symptoms after 2 weeks, those in the optimal choice set condition were no longer significantly more satisfied with their choice at the end of testing. Implications for medical practice, especially patient choice, are discussed.

How Many Atheists Are There? Indirect estimate is 26%

How Many Atheists Are There? Will M. Gervais, Maxine B. Najle. Social Psychological and Personality Science,

Abstract: One crucible for theories of religion is their ability to predict and explain the patterns of belief and disbelief. Yet, religious nonbelief is often heavily stigmatized, potentially leading many atheists to refrain from outing themselves even in anonymous polls. We used the unmatched count technique and Bayesian estimation to indirectly estimate atheist prevalence in two nationally representative samples of 2,000 U.S. adults apiece. Widely cited telephone polls (e.g., Gallup, Pew) suggest U.S. atheist prevalence of only 3–11%. In contrast, our most credible indirect estimate is 26% (albeit with considerable estimate and method uncertainty). Our data and model predict that atheist prevalence exceeds 11% with greater than .99 probability and exceeds 20% with roughly .8 probability. Prevalence estimates of 11% were even less credible than estimates of 40%, and all intermediate estimates were more credible. Some popular theoretical approaches to religious cognition may require heavy revision to accommodate actual levels of religious disbelief.

Keywords: religion, atheism, social desirability, stigma, Bayesian estimation