Homosexuality as a discrete class.

Norris et al. contribute to previous work engaging the question of whether homosexuality has a taxonic structure of categories of individuals with distinct orientation, or whether sexual orientation lies on the sort of continuum suggested by Kinsey and others. Because individuals who report nonheterosexual identities, behavior, and attractions are more likely than heterosexual individuals to meet criteria for a psychiatric disorder their study utilized a National Epidemiologic Survey on Alcohol and Related Conditions. The survey was conducted through personal interviews with one randomly selected adult in each household. Their abstract:

Previous research on the latent structure of sexual orientation has returned conflicting results, with some studies finding a dimensional structure (i.e., ranging quantitatively along a spectrum) and others a taxonic structure (i.e., categories of individuals with distinct orientations). The current study used a sample (N = 33,525) from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). A series of taxometric analyses were conducted using three indicators of sexual orientation: identity, behavior, and attraction. These analyses, performed separately for women and men, revealed low-base-rate same-sex-oriented taxa for men (base rate = 3.0% of those sampled) and women (base rate = 2.7%). Generally, taxon membership conferred an increased risk for psychiatric and substance-use disorders. Although taxa were present for men and women, women demonstrated greater sexual fluidity, such that any level of same-sex sexuality conferred taxon membership for men but not for women.

Another installment on anti-aging chemistry - pterostilbene

I thought I would report on my recent meandering into recent work on the putative anti-aging compounds Resveratrol and Pterostilbene, which are found in some fruits, nuts, and vegetables. (I reported my experience with resveratrol in a 2008 MindBlog post.) The meandering started with a glance at Weintraub's piece on health benefits of red wine versus grape juice. She quoted M.I.T. anti-aging researcher Leonard Guarente, who started the company Elysium, which sells Pterostilbene, a resveratrol cousin that is more easily absorbed after oral ingestion:

Poulose et al. have recently reviewed articles on the effects of pterostilbene and resveratrol on brain health and chemistry (motivated readers can obtain a PDF from me, see also the article by Mitteldorf and the website examine.com).

Even after the neutral to negative experience with resveratrol that I reported in the MindBlog post mentioned above, I've just ordered a bit of pterostilbene to see if I experience some of the cognitive effects claimed.  I'll report on the experience.

How to be bad together - Punishing pro-social behavior.

I pass on part of a brief essay by Gloria Origgi noting the work of Gächter and Herrmann, who examined positive and negative reciprocity in different groups selected within Switzerland and Russia.:

There is a vast literature showing how direct and indirect reciprocity are important tools for dealing with human cooperation. Many experiments have shown that people use “altruistic punishment” to sustain cooperation, that is, they are willingly to pay without receiving anything back just in order to sanction those who don’t cooperate, and hence promote pro-social behavior.

Yet, Gächter and Herrmann showed in their surprising paper that in some cultures, when people were tested in cooperative games (such as the “public good game”), the people who cooperated were punished, rather than the free-riders.

In some societies, people prefer to act anti-socially and they take actions to make sure that the others do the same! This means that cooperation in societies is not always for the good: you can find cartels of anti-social people who don’t care at all for the common good and prefer to cooperate for keeping a status quo that suits them even if the collective outcome is a mediocre result.

As an Italian with first-hand experience in living in a country where, if you behave well, you are socially and legally sanctioned, this news was exciting, even inspiring … perhaps cooperation is not an inherent virtue of the human species. Perhaps, in many circumstances, we prefer to stay with those who share our selfishness and weaknesses and to avoid pro-social altruistic individuals. Perhaps it's not abnormal to live outside a circle of empathy.

So what’s the scientific “news that stays news”: Cooperation for the collective worse is as widespread as cooperation for a better society!

Purity, Disgust and Donald Trump

Following the thread of the past few posts (on the partisan divide and empathy), I want to pass on this must-read article by Thomas Edsall, who summarizes work of academic researchers probing the role of purity/disgust, order/chaos, anger and fear, in the electorate. Here is a great graphic from the article:

Our strongest prejudice - partisan hostility

Jonathan Haidt points to the fascinating work by political scientists Shanto Iyengar and Sean Westwood, titled “Fear and Loathing Across Party Lines: New Evidence on Group Polarization.”, who found - in four studies designed to reveal prejudice based on race, gender, religion, or political party or ideology - that cross-partisan prejudice was the largest. For white participants who identified with a party, the cross-partisan effect was about 50 percent larger than the cross-race effect. Haidt points out that This is extremely bad news for America because:

...rising cross-partisan hostility means that Americans increasingly see the other side not just as wrong but as evil, as a threat to the very existence of the nation, according to Pew Research. Americans can expect rising polarization, nastiness, paralysis, and governmental dysfunction for a long time to come...This is extremely bad news for science and universities because universities are usually associated with the left...we can expect increasing hostility from Republican legislators toward universities and the things they desire, including research funding and freedom from federal and state control...This is a warning for the rest of the world because some of the trends that have driven America to this point are occurring in many other countries, including: rising education and individualism (which make people more ideological), rising immigration and ethnic diversity (which reduces social capital and trust), and stagnant economic growth (which puts people into a zero-sum mindset).

The situation is made worse by the "motive attribution asymmetry" that I have referenced in a previous post. Both sides of a political divide attribute their own aggressive behavior to love, but the opposite side's to hatred. Millions of Americans believe that their side is basically benevolent while the other side is evil and out to get them.

How learning shapes the empathic brain.

From Hein et al.:

Abstract

Deficits in empathy enhance conflicts and human suffering. Thus, it is crucial to understand how empathy can be learned and how learning experiences shape empathy-related processes in the human brain. As a model of empathy deficits, we used the well-established suppression of empathy-related brain responses for the suffering of out-groups and tested whether and how out-group empathy is boosted by a learning intervention. During this intervention, participants received costly help equally often from an out-group member (experimental group) or an in-group member (control group). We show that receiving help from an out-group member elicits a classical learning signal (prediction error) in the anterior insular cortex. This signal in turn predicts a subsequent increase of empathy for a different out-group member (generalization). The enhancement of empathy-related insula responses by the neural prediction error signal was mediated by an establishment of positive emotions toward the out-group member. Finally, we show that surprisingly few positive learning experiences are sufficient to increase empathy. Our results specify the neural and psychological mechanisms through which learning interacts with empathy, and thus provide a neurobiological account for the plasticity of empathic reactions.

Virtual reality going mainstream will enhance our understanding of consciousness.

These clips from Thomas Metzinger are fascinating:

2016 will be the year in which VR finally breaks through at the mass consumer level. What is more, users will soon be enabled to toggle between virtual, augmented, and substitutional reality, experiencing virtual elements intermixed with their “actual” physical environment or an omnidirectional video feed giving them the illusion of being in a different location in space and/or time, while insight may not always be preserved. Oculus Rift, Zeiss VR One, Sony PlayStation VR, HTC Vive, Samsung’s Galaxy Gear VR or Microsoft’s HoloLens are just the very beginning...

The real news, however, may be that the general public will gradually acquire a new and intuitive understanding of what their very own conscious experience really is and what it always has been. VR is the representation of possible worlds and possible selves, with the aim of making them appear as real as possible—ideally, by creating a subjective sense of “presence” in the user. Interestingly, some of our best theories of the human mind and conscious experience describe it in a very similar way: Leading theoretical neurobiologists like Karl Friston and eminent philosophers like Jakob Hohwy and Andy Clark describe it as the constant creation of internal models of the world, virtual neural representations of reality which express probability density functions and work by continuously generating hypotheses about the hidden causes of sensory input, minimizing their prediction error. In 1995, Finnish philosopher Antti Revonsuo already pointed out how conscious experience exactly is a virtual model of the world, a dynamic internal simulation, which in standard situations cannot be experienced as a virtual model because it is phenomenally transparent—we “look through it” as if we were in direct and immediate contact with reality. What is historically new, and what creates not only novel psychological risks but also entirely new ethical and legal dimensions, is that one virtual reality gets ever more deeply embedded into another virtual reality: The conscious mind of human beings, which has evolved under very specific conditions and over millions of years, now gets causally coupled and informationally woven into technical systems for representing possible realities. Increasingly, consciousness is not only culturally and socially embedded, but also shaped by a specific technological niche that, over time, quickly acquires rapid, autonomous dynamics and ever new properties. This creates a complex convolution, a nested form of information flow in which the biological mind and its technological niche influence each other in ways we are just beginning to understand.

How our brains change during the day.

I am reminded what a rigid daily schedule my body keeps and expects every time I vary my routine slightly (changing a meal time, exercise, happy hour, bedtime)...my body doesn't like it, feels off kilter. Travel of the sort I've been doing over the past month is a huge disrupter. I'm also clear that any demanding and analytical thinking I might want to do should happen before noontime, because by 4 p.m. (a low blood sugar time for the body), my mind has become very lazy.

McClung and collaborators have done the fascinating experiment of looking at gene expression during the day in brain areas important in learning, memory, and emotion, in 146 young and old brains, finding differences on aging. The brains were from subjects who had died suddenly, as in a car accident. They built on the work of Akil and collaborators who earlier had shown the activity of ~1000 genes varies in a daily pattern that allows the time of death to be predicted within an hour. That pattern was disrupted in people with major depressive disorders. From McClung's group:  

Significance

Circadian rhythms are important in nearly all processes in the brain. Changes in rhythms that come with aging are associated with sleep problems, problems with cognition, and nighttime agitation in elderly people. In this manuscript, we identified transcripts genome-wide that have a circadian rhythm in expression in human prefrontal cortex. Moreover, we describe how these rhythms are changed during normal human aging. Interestingly, we also identified a set of previously unidentified transcripts that become rhythmic only in older individuals. This may represent a compensatory clock that becomes active with the loss of canonical clock function. These studies can help us to develop therapies in the future for older people who suffer from cognitive problems associated with a loss of normal rhythmicity.

Abstract

With aging, significant changes in circadian rhythms occur, including a shift in phase toward a “morning” chronotype and a loss of rhythmicity in circulating hormones. However, the effects of aging on molecular rhythms in the human brain have remained elusive. Here, we used a previously described time-of-death analysis to identify transcripts throughout the genome that have a significant circadian rhythm in expression in the human prefrontal cortex [Brodmann’s area 11 (BA11) and BA47]. Expression levels were determined by microarray analysis in 146 individuals. Rhythmicity in expression was found in ∼10% of detected transcripts (P less than 0.05). Using a metaanalysis across the two brain areas, we identified a core set of 235 genes (q less than 0.05) with significant circadian rhythms of expression. These 235 genes showed 92% concordance in the phase of expression between the two areas. In addition to the canonical core circadian genes, a number of other genes were found to exhibit rhythmic expression in the brain. Notably, we identified more than 1,000 genes (1,186 in BA11; 1,591 in BA47) that exhibited age-dependent rhythmicity or alterations in rhythmicity patterns with aging. Interestingly, a set of transcripts gained rhythmicity in older individuals, which may represent a compensatory mechanism due to a loss of canonical clock function. Thus, we confirm that rhythmic gene expression can be reliably measured in human brain and identified for the first time (to our knowledge) significant changes in molecular rhythms with aging that may contribute to altered cognition, sleep, and mood in later life.

Nature's warning system.

A colleague in my Chaos and Complexity discussion group at the Univ. of Wisconsin passed on this Atlantic article in which my Zoology colleague Steve Carpenter is extensively quoted, which is well worth reading. Complex systems, like ecological food webs, the brain, and the climate, give off characteristic signals when a disastrous transformation is around the corner.

Higher inequality correlates with less generous rich people.

From Côté et. al.:

Research on social class and generosity suggests that higher-income individuals are less generous than poorer individuals. We propose that this pattern emerges only under conditions of high economic inequality, contexts that can foster a sense of entitlement among higher-income individuals that, in turn, reduces their generosity. Analyzing results of a unique nationally representative survey that included a real-stakes giving opportunity (n = 1,498), we found that in the most unequal US states, higher-income respondents were less generous than lower-income respondents. In the least unequal states, however, higher-income individuals were more generous. To better establish causality, we next conducted an experiment (n = 704) in which apparent levels of economic inequality in participants’ home states were portrayed as either relatively high or low. Participants were then presented with a giving opportunity. Higher-income participants were less generous than lower-income participants when inequality was portrayed as relatively high, but there was no association between income and generosity when inequality was portrayed as relatively low. This research finds that the tendency for higher-income individuals to be less generous pertains only when inequality is high, challenging the view that higher-income individuals are necessarily more selfish, and suggesting a previously undocumented way in which inequitable resource distributions undermine collective welfare... Our findings offer a more complete understanding of the association between income and generosity and have implications for contemporary debates about the social impact of unequal resource distributions.

A positive tonic: Human Progress Quantified

Edge.org has just posted responses to its 2016 question of the year "What do you consider the most interesting recent [scientific] news? What makes it important?" Over the next period of time I'm going to be posting edited clips from some of these responses, starting today with Steven Pinker's contribution on human progress:

Human intuition is a notoriously poor guide to reality...Fortunately, as the bugs in human cognition have become common knowledge, the workaround—objective data—has become more prevalent...Sports have been revolutionized by Moneyball, policy by Nudge, punditry by 538.com, forecasting by tournaments and prediction markets, philanthropy by effective altruism, the healing arts by evidence-based medicine.

The most interesting news is that the quantification of life has been extended to the biggest question of all: Have we made progress... in improving the human condition?...Most people agree that life is better than death, health better than disease, prosperity better than poverty, knowledge better than ignorance, peace better than war, safety better than violence, freedom better than coercion. That gives us a set of yardsticks by which we can measure whether progress has actually occurred. The interesting news is that the answer is mostly "yes."... the rate of homicides and war deaths had plummeted over time...People are living longer and healthier lives, not just in the developed world but globally. A dozen infectious and parasitic diseases are extinct or moribund. Vastly more children are going to school and learning to read. Extreme poverty has fallen worldwide from 85 to 10 percent. Despite local setbacks, the world is more democratic than ever. Women are better educated, marrying later, earning more, and in more positions of power and influence. Racial prejudice and hate crimes have decreased since data were first recorded. The world is even getting smarter: In every country, IQ has been increasing by three points a decade.

"Ecomodernists" such as Stewart Brand, Jesse Ausubel, and Ruth DeFries have shown that many indicators of environmental health have improved over the last half-century, and that there are long-term historical processes, such as the decarbonization of energy, the dematerialization of consumption, and the minimization of farmland that can be further encouraged...for all the ways in which the world today falls short of utopia, the norms and institutions of modernity have put us on a good track. We should work on improving them further, rather than burning them down in the conviction that nothing could be worse than our current decadence and in the vague hope that something better might rise from their ashes...quantified human progress emboldens us to seek more of it...The empowering feature of a graph is that it invites one to identify the forces that are pushing a curve up or down, and then to apply them to push it further in the same direction.

Boosting our brain plasticity.

Wow, this study by Forsyth et al. makes me want to run out and buy a bottle of D-cycloserine, which they show enhances experience-dependent learning, i.e. brain plasticity, in healthy adult humans. (Actually, it's expensive, and experimenting with it by yourself is not a good idea.)

 Significance

Experience-dependent plasticity is the capacity of the brain to undergo changes following environmental input and use, and is a primary means through which the adult brain enables new behavior. In the current study, we provide evidence that enhancing signaling at the glutamate N-methyl-D-aspartate receptor (NMDAR) can enhance the mechanism underlying many forms of experience-dependent plasticity (i.e., long-term potentiation of synaptic currents) and also enhance experience-dependent learning in healthy adult humans. This suggests exciting possibilities for manipulating plasticity in adults and has implications for treating neurological and neuropsychiatric disorders in which experience-dependent plasticity is impaired.

Abstract

Experience-dependent plasticity is a fundamental property of the brain. It is critical for everyday function, is impaired in a range of neurological and psychiatric disorders, and frequently depends on long-term potentiation (LTP). Preclinical studies suggest that augmenting N-methyl-D-aspartate receptor (NMDAR) signaling may promote experience-dependent plasticity; however, a lack of noninvasive methods has limited our ability to test this idea in humans until recently. We examined the effects of enhancing NMDAR signaling using D-cycloserine (DCS) on a recently developed LTP EEG paradigm that uses high-frequency visual stimulation (HFvS) to induce neural potentiation in visual cortex neurons, as well as on three cognitive tasks: a weather prediction task (WPT), an information integration task (IIT), and a n-back task. The WPT and IIT are learning tasks that require practice with feedback to reach optimal performance. The n-back assesses working memory. Healthy adults were randomized to receive DCS (100 mg; n = 32) or placebo (n = 33); groups were similar in IQ and demographic characteristics. Participants who received DCS showed enhanced potentiation of neural responses following repetitive HFvS, as well as enhanced performance on the WPT and IIT. Groups did not differ on the n-back. Augmenting NMDAR signaling using DCS therefore enhanced activity-dependent plasticity in human adults, as demonstrated by lasting enhancement of neural potentiation following repetitive HFvS and accelerated acquisition of two learning tasks. Results highlight the utility of considering cellular mechanisms underlying distinct cognitive functions when investigating potential cognitive enhancers.

Negative evaluation of counterstereotypical people by conservatives maintains their sense of certainty

Yet another study on differences in the psychology of conservative and liberal individuals:

People frequently use physical appearance stereotypes to categorize individuals when their group membership is not directly observable. Recent research indicates that political conservatives tend to use such stereotypes more than liberals do because they express a greater desire for certainty and order. In the present research, we found that conservatives were also more likely to negatively evaluate and distribute fewer economic resources to people who deviate from the stereotypes of their group. This occurred for people belonging to both preexisting and novel groups, regardless of whether the stereotypes were real or experimentally fabricated. Critically, conservatives only negatively evaluated counterstereotypical people when the stereotypes were functional—that is, when they expected that they would need to use the stereotypes at a later point to categorize individuals into groups. Moreover, increasing liberals’ desire for certainty led them to negatively evaluate counterstereotypical people just like conservatives did. Thus, conservatives are not only more likely to use stereotypes than are liberals, but are especially likely to negatively evaluate counterstereotypical people to organize the social world with greater certainty.

Dorsal and Ventral Right Brain Pathways for Prosody

Sammler et al. show that analysis of the emotional content, or vocal tone, of our speech is processed in dorsal and ventral streams of the right hemisphere much as phonology, syntax, and semantics are processed by dorsal and ventral streams of the left hemisphere:

Our vocal tone—the prosody—contributes a lot to the meaning of speech beyond the actual words. Indeed, the hesitant tone of a “yes” may be more telling than its affirmative lexical meaning. The human brain contains dorsal and ventral processing streams in the left hemisphere that underlie core linguistic abilities such as phonology, syntax, and semantics. Whether or not prosody — a reportedly right-hemispheric faculty — involves analogous processing streams is a matter of debate. Functional connectivity studies on prosody leave no doubt about the existence of such streams, but opinions diverge on whether information travels along dorsal or ventral pathways. Here we show, with a novel paradigm using audio morphing combined with multimodal neuroimaging and brain stimulation, that prosody perception takes dual routes along dorsal and ventral pathways in the right hemisphere. In experiment 1, categorization of speech stimuli that gradually varied in their prosodic pitch contour (between statement and question) involved (1) an auditory ventral pathway along the superior temporal lobe and (2) auditory-motor dorsal pathways connecting posterior temporal and inferior frontal/premotor areas. In experiment 2, inhibitory stimulation of right premotor cortex as a key node of the dorsal stream decreased participants’ performance in prosody categorization, arguing for a motor involvement in prosody perception. These data draw a dual-stream picture of prosodic processing that parallels the established left-hemispheric multi-stream architecture of language, but with relative rightward asymmetry.

Brain mitochondria function links anxiety with social subordination.

Hollis et al. make the fascinating observation that position in the social hierarchy of rats (dominant versus submissive) can be enhanced or diminished by stimulating or inhibiting energy metabolism of mitochondria in the nucleus accumbens, a brain region that regulates motivation and depression. It is interesting that several of the human dietary supplements that can be purchased from websites promoting brain rejuvenation contain stimulators of mitochondrial function. (I have noted one of these in a previous post.)

Dominance hierarchies are integral aspects of social groups, yet whether personality traits may predispose individuals to a particular rank remains unclear. Here we show that trait anxiety directly influences social dominance in male outbred rats and identify an important mediating role for mitochondrial function in the nucleus accumbens. High-anxious animals that are prone to become subordinate during a social encounter with a low-anxious rat exhibit reduced mitochondrial complex I and II proteins and respiratory capacity as well as decreased ATP and increased ROS production in the nucleus accumbens. A causal link for these findings is indicated by pharmacological approaches. In a dyadic contest between anxiety-matched animals, microinfusion of specific mitochondrial complex I or II inhibitors into the nucleus accumbens reduced social rank, mimicking the low probability to become dominant observed in high-anxious animals. Conversely, intraaccumbal infusion of nicotinamide, an amide form of vitamin B3 known to enhance brain energy metabolism, prevented the development of a subordinate status in high-anxious individuals. We conclude that mitochondrial function in the nucleus accumbens is crucial for social hierarchy establishment and is critically involved in the low social competitiveness associated with high anxiety. Our findings highlight a key role for brain energy metabolism in social behavior and point to mitochondrial function in the nucleus accumbens as a potential marker and avenue of treatment for anxiety-related social disorders.

Socioeconomic status, inflammatory reactivity, and social support.

Interesting work from John-Henderson et al., who suggest that social support is more effective in damping stress responses in people having childhoods with low socioeconomic status than in people with high childhood socioeconomic status.:

Low socioeconomic status (SES) during childhood confers risk for adverse health in adulthood. Accumulating evidence suggests that this may be due, in part, to the association between lower childhood SES and higher levels of pro-inflammatory cytokines. Drawing from literature showing that low childhood SES predicts exaggerated physiological reactivity to stressors and that lower SES is associated with a more communal, socially attuned orientation, we hypothesized that inflammatory reactivity would be more greatly affected by cues of social support among individuals whose childhood SES was low than among those whose childhood SES was high. In two studies, we found that individuals with lower subjective childhood SES exhibited greater reductions in pro-inflammatory cytokine reactivity to a stressor in the presence of a supportive figure (relative to conditions with an unsupportive or neutral figure). These effects were independent of current SES. This work helps illuminate SES-based differences in inflammatory reactivity to stressors, particularly among individuals whose childhood SES was low.

The need for affiliation - communities of kindness

I belong to the Gay Men's Chorus of South Florida, which completed a series of five Christmas season concerts over the past two weeks. Singing in these performances, and doing a piano duet accompaniment for one of the pieces, I was exhausted for several days. Being in the chorus reminds me of church and boy scout groups of my youth. It is a communal setting where there is a sense of family, laughter, love and community. I am struck by parallels with Mark Oppenheimer's description of another secular equivalent to church communities, the CrossFit gym movement.

A for-profit gym franchise founded in 2000 that now has 13,000 licensed operators serving at least two million exercisers, CrossFit — like television, sports fandom and health fads — has become the focus of study by researchers trying to pinpoint what constitutes religiosity in America.

Members speak about their "box," or gym..

...as others might speak about a church or synagogue community. The same is true of some 12-step program members, and devoted college-football fans. In an increasingly secular America, all sorts of activities and subcultures provide the meaning that in the past, at least as we imagine it, religious communities did.

The article outlines several parallels between CrossFit and religious communities. From one member:

What really struck us was the way in which people were bringing their kids to their box...or the way different workouts of the day were named after soldiers who had died in battle. So there’s all of these things you would expect to see in a church — remembering the dead through some sort of ritual, and intergenerational community.

In a similar vein, David Brooks writes about educational communities of character. He cites a number of examples of secondary school settings that emphasize kindness, respect, and responsibility in binding together a learning community.

Empathy is a choice, and can be trained.

I want to pass on some clips from a review by Cameron et al. that summarizes, and has links to, a number of studies that deal our ability to share the experiences of others.

While a single crying child or injured puppy tugs at our heartstrings, large numbers of suffering people, as in epidemics, earthquakes and genocides, do not inspire a comparable reaction...Not only does empathy seem to fail when it is needed most, but it also appears to play favorites. Recent studies have shown that our empathy is dampened or constrained when it comes to people of different races, nationalities or creeds. These results suggest that empathy is a limited resource, like a fossil fuel, which we cannot extend indefinitely or to everyone.

While we concede that the exercise of empathy is, in practice, often far too limited in scope, we dispute the idea that this shortcoming is inherent, a permanent flaw in the emotion itself. Inspired by a competing body of recent research, we believe that empathy is a choice that we make whether to extend ourselves to others...one of us, Daryl Cameron, along with the psychologist Keith Payne, conducted an experiment to see if ...motivational factors could explain why we seem more empathetic to single victims than to large numbers of them.

Participants in this study read about either one or eight child refugees from the Darfur region of Sudan. Half of the participants were led to expect that they would be asked to make a donation to the refugee or refugees, whereas the other half were not. When there was no financial cost involved in feeling empathy, people felt more empathy for the eight children than for the one child, reversing the usual bias. If insensitivity to mass suffering stemmed from an intrinsic limit to empathy, such financial factors shouldn’t have made a difference.

Likewise, in another recent study, the psychologists Karina Schumann, Jamil Zaki and Carol S. Dweck found that when people learned that empathy was a skill that could be improved — as opposed to a fixed personality trait — they engaged in more effort to experience empathy for racial groups other than their own. Empathy for people unlike us can be expanded, it seems, just by modifying our views about empathy.

Male and female brains do not constitute two distinct categories.

From Zoel et al.: Significance

Sex/gender differences in the brain are of high social interest because their presence is typically assumed to prove that humans belong to two distinct categories not only in terms of their genitalia, and thus justify differential treatment of males and females. Here we show that, although there are sex/gender differences in brain and behavior, humans and human brains are comprised of unique “mosaics” of features, some more common in females compared with males, some more common in males compared with females, and some common in both females and males. Our results demonstrate that regardless of the cause of observed sex/gender differences in brain and behavior (nature or nurture), human brains cannot be categorized into two distinct classes: male brain/female brain.

Abstract

Whereas a categorical difference in the genitals has always been acknowledged, the question of how far these categories extend into human biology is still not resolved. Documented sex/gender differences in the brain are often taken as support of a sexually dimorphic view of human brains (“female brain” or “male brain”). However, such a distinction would be possible only if sex/gender differences in brain features were highly dimorphic (i.e., little overlap between the forms of these features in males and females) and internally consistent (i.e., a brain has only “male” or only “female” features). Here, analysis of MRIs of more than 1,400 human brains from four datasets reveals extensive overlap between the distributions of females and males for all gray matter, white matter, and connections assessed. Moreover, analyses of internal consistency reveal that brains with features that are consistently at one end of the “maleness-femaleness” continuum are rare. Rather, most brains are comprised of unique “mosaics” of features, some more common in females compared with males, some more common in males compared with females, and some common in both females and males. Our findings are robust across sample, age, type of MRI, and method of analysis. These findings are corroborated by a similar analysis of personality traits, attitudes, interests, and behaviors of more than 5,500 individuals, which reveals that internal consistency is extremely rare. Our study demonstrates that, although there are sex/gender differences in the brain, human brains do not belong to one of two distinct categories: male brain/female brain.

Good news for the grumpy.

A dogma of the self-help and happiness industries is that unhappiness decreases health and longevity. Happy people are supposed to live longer. Not so, it turns out, according to a British study published in The Lancet that followed one million middle-aged women in Britan for 10 years. Previous work may have confused cause and effect, suggesting that unhappiness made people ill, when it was actually the other way around. Bottom line from the article:

In middle-aged women, poor health can cause unhappiness. After allowing for this association and adjusting for potential confounders, happiness and related measures of wellbeing do not appear to have any direct effect on mortality.