Genes and environments, development and time

 A special section of the Sept. 22 issue of PNAS offers a series of free online artices on biological embedding across timescales.  Here is the abstract of the introductory article by Boyce et al.:

A now substantial body of science implicates a dynamic interplay between genetic and environmental variation in the development of individual differences in behavior and health. Such outcomes are affected by molecular, often epigenetic, processes involving gene–environment (G–E) interplay that can influence gene expression. Early environments with exposures to poverty, chronic adversities, and acutely stressful events have been linked to maladaptive development and compromised health and behavior. Genetic differences can impart either enhanced or blunted susceptibility to the effects of such pathogenic environments. However, largely missing from present discourse regarding G–E interplay is the role of time, a “third factor” guiding the emergence of complex developmental endpoints across different scales of time. Trajectories of development increasingly appear best accounted for by a complex, dynamic interchange among the highly linked elements of genes, contexts, and time at multiple scales, including neurobiological (minutes to milliseconds), genomic (hours to minutes), developmental (years and months), and evolutionary (centuries and millennia) time. This special issue of PNAS thus explores time and timing among G–E transactions: The importance of timing and timescales in plasticity and critical periods of brain development; epigenetics and the molecular underpinnings of biologically embedded experience; the encoding of experience across time and biological levels of organization; and gene-regulatory networks in behavior and development and their linkages to neuronal networks. Taken together, the collection of papers offers perspectives on how G–E interplay operates contingently within and against a backdrop of time and timescales.

Inflammaging - Another reason seniors don't want to catch COVID-19

I imagine myself to have a very robust immune system because I very seldom catch a flu or cold, take Vitamins C and D, exercise, am not overweight, ran around barefoot when I was 3-4 years old, eating dirt and pill bugs outside the family house I have now moved back into 75 years later. This optimistic view is tempered quite a bit by information in Greenwoods's recent article describing how the aging immune system begins to shift into a heightened state of alert, dialing up inflammation and running out of certain immune cells. This is because the body's first line of defense against virus infiltration, that normally also cleans up damaged cells, misfolded proteins and other detritus in the body - even in the absence of an infection - begins to be overwhelmed by increasing amount of waste, and slides into a constant state of alert and inflammation. And...

At the same time, elderly cells in tissues throughout the body are thought to change with age, releasing inflammatory substances of their own...even perfectly healthy 65-year-olds usually have higher levels of immune proteins, like cytokines, involved in inflammation than younger people do. This heightened state of chronic inflammation, sometimes called “inflammaging,” is linked to frailty — older adults with higher levels of it may be more fragile and less mobile...fighting off pathogens becomes more complicated: All of this baseline inflammatory chaos in an aging body makes it harder for the messages sent out by the innate immune system to reach their targets...there’s the added danger that the innate immune system may overreact...the aging immune system might be linked to reports of severe Covid-19 culminating in a cytokine storm, a reaction that causes high numbers of immune messengers to flood the body and can lead to organ failure...This inflammation may also be part of why vaccines, whose effectiveness relies on a robust reaction from the immune system, don’t work as well in older people — an effect that’s likely to extend to Covid-19 vaccines.

Several days after the innate immune response begins, the body begins a second wave of attacks against the viral invader. This adaptive immune system response is more targeted than the first, methodically destroying cells infected by this specific virus...in older bodies, the adaptive response not only takes longer to get into gear, it arrives to find a scene of inflammatory pandemonium...These delays mean that the pathogen has already made many copies of itself by the time the adaptive immune system gets to work and gains a foothold that might not have been available in a younger person. Additionally, older people have fewer fresh T cells, important players in the adaptive response that are trained to hunt down cells infected with a specific pathogen.

Since it became clear that the virus sometimes provokes an out-of-control immune response, researchers have been testing whether reducing inflammation might help. Drugs that tamp down the levels of cytokines, like those used for treating rheumatoid arthritis and other autoimmune diseases, have not shown success in fighting the virus. What’s more, chloroquine, which can help inhibit the aging of cells, caused increased mortality in Covid-19 clinical trials.

But the steroid dexamethasone, a potent anti-inflammatory, has been shown to reduce deaths from the virus. It resulted in one-third fewer deaths in people on ventilators and one-fifth fewer deaths in those on oxygen, according to a study published in June. (The drug may be ineffective, or even harmful, for patients in the early stages of the disease, however.)

The 2020 Ig Nobel Prizes - research on knives made of feces.

A piece in Science Magazine gives the highlights of this year's Ig Noble prize s published in the Annals of Improbable Research. If the award for research showing that knives can not be made from feces (despite a previous account of an Inuit man doing so) turns you on, you might also enjoy this Poop Mystery Story in the New Yorker Magazine.

Brain circuits signaling the absence of emotion in body language

Sokolov et al. show that modulation of the reciprocal effective connectivity between the amygdala and insula during processing of neutral and emotional body language predicts people’s ability to recognize neutral body language, suggesting that their interplay may be important not only for the processing of emotions but also, for inferring the absence of emotional content in body language. Their abstract:

Adaptive social behavior and mental well-being depend on not only recognizing emotional expressions but also, inferring the absence of emotion. While the neurobiology underwriting the perception of emotions is well studied, the mechanisms for detecting a lack of emotional content in social signals remain largely unknown. Here, using cutting-edge analyses of effective brain connectivity, we uncover the brain networks differentiating neutral and emotional body language. The data indicate greater activation of the right amygdala and midline cerebellar vermis to nonemotional as opposed to emotional body language. Most important, the effective connectivity between the amygdala and insula predicts people’s ability to recognize the absence of emotion. These conclusions extend substantially current concepts of emotion perception by suggesting engagement of limbic effective connectivity in recognizing the lack of emotion in body language reading. Furthermore, the outcome may advance the understanding of overly emotional interpretation of social signals in depression or schizophrenia by providing the missing link between body language reading and limbic pathways. The study thus opens an avenue for multidisciplinary research on social cognition and the underlying cerebrocerebellar networks, ranging from animal models to patients with neuropsychiatric conditions.

Another Big History - why the West is WEIRD (Western, educated, industrialized, rich, democratic)

Alas, I usually end up reading reviews of books rather than the books themselves. Here I want to pass on clips from Shulevitz's review in The Atlantic: of Joseph Henrich's theory-of-everything type book: "The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous." Henrich directs Harvard’s Department of Human Evolutionary Biology.

Consider this the latest addition to the Big History category, popularized by best sellers such as Jared Diamond’s Guns, Germs, and Steel: The Fates of Human Societies and Yuval Noah Harari’s Sapiens: A Brief History of Humankind. The outstanding feature of the genre is that it wrangles all of human existence into a volume or two, starting with the first hominids to rise up on their hind legs and concluding with us, cyborg-ish occupants of a networked globe. Big History asks Big Questions and offers quasi-monocausal answers. Why and how did humans conquer the world? Harari asks. Cooperation. What explains differences and inequalities among civilizations? Diamond asks. Environment, which is to say, geography, climate, flora and fauna. Henrich also wants to explain variation among societies, in particular to account for the Western, prosperous kind.

One culture... is different from the others, and that’s modern WEIRD (“Western, educated, industrialized, rich, democratic”) culture. Henrich’s ambition is tricky: to account for Western distinctiveness while undercutting Western arrogance. He rests his grand theory of cultural difference on an inescapable fact of the human condition: kinship, one of our species’ “oldest and most fundamental institutions.”...Higher-order institutions—governments and armies as well as religions—evolved from kin-based institutions...The Catholic Church changed all that. As of late antiquity, Europeans still lived in tribes, like most of the rest of the world. But the Church dismantled these kin-based societies with what Henrich calls its “Marriage and Family Program,..it meant quashing pagan practices such as polygamy, arranged marriages (Christian matrimony was notionally consensual, hence the formula “I do”), and above all, marriages between relatives, which the Church was redefining as incest.. ..Forced to find Christian partners, Christians left their communities. Christianity’s insistence on monogamy broke extended households into nuclear families. The Church uprooted horizontal, relational identity, replacing it with a vertical identity oriented toward the institution itself...Formerly, property almost always went to family members. The idea now took hold that it could go elsewhere. At the same time, the Church urged the wealthy to ensure their place in heaven by bequeathing their money to the poor—that is, to the Church, benefactor to the needy...The Church, thus enriched, spread across the globe...Loosened from their roots, people gathered in cities. There they developed “impersonal prosociality”—that is, they bonded with other city folk. They wrote city charters and formed professional guilds. Sometimes they elected leaders, the first inklings of representative democracy.

Why, if Italy has been Catholic for so long, did northern Italy become a prosperous banking center, while southern Italy stayed poor and was plagued by mafiosi? The answer, Henrich declares, is that southern Italy was never conquered by the Church-backed Carolingian empire. Sicily remained under Muslim rule and much of the rest of the south was controlled by the Orthodox Church until the papal hierarchy finally assimilated them both in the 11th century. This is why, according to Henrich, cousin marriage in the boot of Italy and Sicily is 10 times higher than in the north, and in most provinces in Sicily, hardly anyone donates blood (a measure of willingness to help strangers), while some northern provinces receive 105 donations of 16-ounce bags per 1,000 people per year.

Henrich’s most consequential—and startling—claim is that WEIRD and non-WEIRD people possess opposing cognitive styles. They think differently. Standing apart from the community, primed to break wholes into parts and classify them, Westerners are more analytical. People from kinship-intensive cultures, by comparison, tend to think more holistically.

Henrich is more persuasive when applying his theory of cumulative culture to the evolution of ideas. Democracy, the rule of law, and human rights “didn’t start with fancy intellectuals, philosophers, or theologians,” Henrich writes. “Instead, the ideas formed slowly, piece by piece, as regular Joes with more individualistic psychologies—be they monks, merchants, or artisans—began to form competing voluntary associations” and learned how to govern them. Toppling the accomplishments of Western civilization off their great-man platforms, he erases their claim to be monuments to rationality: Everything we think of as a cause of culture is really an effect of culture, including us.

Ethnic antagonism erodes Republicans’ commitment to democracy

Bartels does a survey (open source) that provides numbers and graphs on what is obvious from current news sources - the frailty of public commitment to democratic norms in the contemporary United States illustrated by the survey responses of 1,151 Republican identifiers and Republican-leaning Independents* interviewed in January 2020:  

Significance

Growing partisan polarization and democratic “backsliding” in various parts of the world have raised concerns about the attachment of ordinary Americans to democratic institutions and procedures. I find that substantial numbers of Republicans endorse statements contemplating violations of key democratic norms, including respect for the law and for the outcomes of elections and eschewing the use of force in pursuit of political ends. The strongest predictor by far of these antidemocratic attitudes is ethnic antagonism—especially concerns about the political power and claims on government resources of immigrants, African-Americans, and Latinos. The strong tendency of ethnocentric Republicans to countenance violence and lawlessness, even prospectively and hypothetically, underlines the significance of ethnic conflict in contemporary US politics.

Abstract

Most Republicans in a January 2020 survey agreed that “the traditional American way of life is disappearing so fast that we may have to use force to save it.” More than 40% agreed that “a time will come when patriotic Americans have to take the law into their own hands.” (In both cases, most of the rest said they were unsure; only one in four or five disagreed.) I use 127 survey items to measure six potential bases of these and other antidemocratic sentiments: partisan affect, enthusiasm for President Trump, political cynicism, economic conservatism, cultural conservatism, and ethnic antagonism. The strongest predictor by far, for the Republican rank-and-file as a whole and for a variety of subgroups defined by education, locale, sex, and political attitudes, is ethnic antagonism—especially concerns about the political power and claims on government resources of immigrants, African-Americans, and Latinos. The corrosive impact of ethnic antagonism on Republicans’ commitment to democracy underlines the significance of ethnic conflict in contemporary US politics.

Disagreeable people are not more likely than agreeable people to obtain power in an organization.

An interesting study from Anderson et al.:

Does being disagreeable—that is, behaving in aggressive, selfish, and manipulative ways—help people attain power? This question has long captivated philosophers, scholars, and laypeople alike, and yet prior empirical findings have been inconclusive. In the current research, we conducted two preregistered prospective longitudinal studies in which we measured participants’ disagreeableness prior to entering the labor market and then assessed the power they attained in the context of their work organization ∼14 y later when their professional careers had unfolded. Both studies found disagreeable individuals did not attain higher power as opposed to extraverted individuals who did gain higher power in their organizations. Furthermore, the null relationship between disagreeableness and power was not moderated by individual differences, such as gender or ethnicity, or by contextual variables, such as organizational culture. What can account for this null relationship? A close examination of behavior patterns in the workplace found that disagreeable individuals engaged in two distinct patterns of behavior that offset each other’s effects on power attainment: They engaged in more dominant-aggressive behavior, which positively predicted attaining higher power, but also engaged in less communal and generous behavior, which predicted attaining less power. These two effects, when combined, appeared to cancel each other out and led to a null correlation between disagreeableness and power.

"Us" versus "Them" in 17 month old infants.

Jin and Baillargeon make observations that suggest an early origin of the 'us and them' perspective being taken to extremes in our current polarized political climate:

Significance

We examined whether one mechanism contributing to ingroup favoritism might be an abstract and early-emerging sociomoral expectation of ingroup support. In violation-of-expectation experiments, 17-mo-old infants first watched third-party interactions among unfamiliar adults identified (using novel labels) as belonging to the same group, to different groups, or to unspecified groups. Next, one adult needed help, and another adult either did or did not provide it. Infants expected help to be provided when the two adults belonged to the same group, but held no expectation when the adults belonged to different groups or to unspecified groups. Infants thus already possess an abstract expectation of ingroup support, and this finding sheds light on one of the mechanisms underlying ingroup favoritism in human interactions.

Abstract

One pervasive facet of human interactions is the tendency to favor ingroups over outgroups. Remarkably, this tendency has been observed even when individuals are assigned to minimal groups based on arbitrary markers. Why is mere categorization into a minimal group sufficient to elicit some degree of ingroup favoritism? We consider several accounts that have been proposed in answer to this question and then test one particular account, which holds that ingroup favoritism reflects in part an abstract and early-emerging sociomoral expectation of ingroup support. In violation-of-expectation experiments with 17-mo-old infants, unfamiliar women were first identified (using novel labels) as belonging to the same group, to different groups, or to unspecified groups. Next, one woman needed instrumental assistance to achieve her goal, and another woman either provided the necessary assistance (help event) or chose not to do so (ignore event). When the two women belonged to the same group, infants looked significantly longer if shown the ignore as opposed to the help event; when the two women belonged to different groups or to unspecified groups, however, infants looked equally at the two events. Together, these results indicate that infants view helping as expected among individuals from the same group, but as optional otherwise. As such, the results demonstrate that from an early age, an abstract expectation of ingroup support contributes to ingroup favoritism in human interactions.

Cognitive control increases honesty in cheaters but cheating in those who are honest

Abe discusses work of Speer et al. that probes:

..a long-standing paradox concerning the cognitive nature of honesty: Is it a matter of “will” or “grace”? The will hypothesis assumes that honesty requires cognitive control to suppress temptation to cheat, while dishonest behavior to serve self-interest is people’s automatic response. In contrast, the grace hypothesis assumes that honesty flows automatically without active resistance to temptation, while dishonest behavior is realized by cognitive control to override honest impulses.

Here is the Speer et al. abstract:

Every day, we are faced with the conflict between the temptation to cheat for financial gains and maintaining a positive image of ourselves as being a “good person.” While it has been proposed that cognitive control is needed to mediate this conflict between reward and our moral self-image, the exact role of cognitive control in (dis)honesty remains elusive. Here we identify this role, by investigating the neural mechanism underlying cheating. We developed a task which allows for inconspicuously measuring spontaneous cheating on a trial-by-trial basis in the MRI scanner. We found that activity in the nucleus accumbens promotes cheating, particularly for individuals who cheat a lot, while a network consisting of posterior cingulate cortex, temporoparietal junction, and medial prefrontal cortex promotes honesty, particularly in individuals who are generally honest. Finally, activity in areas associated with cognitive control (anterior cingulate cortex and inferior frontal gyrus) helped dishonest participants to be honest, whereas it enabled cheating for honest participants. Thus, our results suggest that cognitive control is not needed to be honest or dishonest per se but that it depends on an individual’s moral default.

Origins of human music - two perspectives

Because I wrote an article in Behavioral and Brain Sciences (coauthored with Vadim Arshavsky), that was published in 2010, I receive the journal's calls for commentaries on forthcoming articles. Here I pass on the abstracts of two articles proposing evolutionary rationales for the origins of our human musical abilities.  Because I am a recital pianist I have always been interested in the origins and neuroscience of our musical faculties. In 2015 I agreed to give a lecture on 'Music and the Mind', generated thirty pages of fairly lucid text, became overwhelmed by the complexity of the subject, and backed out of doing the talk.  I'm curious to see whether a careful reading of these articles confirms that decision or inspires me to try again. 

Music as a coevolved system for social bonding

Why do humans make music? Theories of the evolution of musicality have focused mainly on the value of music for specific adaptive contexts such as mate selection, parental care, coalition signaling, and group cohesion. Synthesizing and extending previous proposals, we argue that social bonding is an overarching function that unifies all of these theories, and that musicality enabled social bonding at larger scales than grooming and other bonding mechanisms available in ancestral primate societies. We combine cross-disciplinary evidence from archaeology, anthropology, biology, musicology, psychology, and neuroscience into a unified framework that accounts for the biological and cultural evolution of music. We argue that the evolution of musicality involves gene-culture coevolution, through which proto-musical behaviors that initially arose and spread as cultural inventions had feedback effects on biological evolution due to their impact on social bonding. We emphasize the deep links between production, perception, prediction, and social reward arising from repetition, synchronization, and harmonization of rhythms and pitches, and summarize empirical evidence for these links at the levels of brain networks, physiological mechanisms, and behaviors across cultures and across species. Finally, we address potential criticisms and make testable predictions for future research, including neurobiological bases of musicality and relationships between human music, language, animal song, and other domains. The music and social bonding (MSB) hypothesis provides the most comprehensive theory to date of the biological and cultural evolution of music.

Origins of music in credible signaling

Music comprises a diverse category of cognitive phenomena that likely represent both the effects of psychological adaptations that are specific to music (e.g., rhythmic entrainment) and the effects of adaptations for non-musical functions (e.g., auditory scene analysis). How did music evolve? Here, we show that prevailing views on the evolution of music — that music is a byproduct of other evolved faculties, evolved for social bonding, or evolved to signal mate quality — are incomplete or wrong. We argue instead that music evolved as a credible signal in at least two contexts: coalitional interactions and infant care. Specifically, we propose that (1) the production and reception of coordinated, entrained rhythmic displays is a co-evolved system for credibly signaling coalition strength, size, and coordination ability; and (2) the production and reception of infant-directed song is a co-evolved system for credibly signaling parental attention to secondarily altricial infants. These proposals, supported by interdisciplinary evidence, suggest that basic features of music, such as melody and rhythm, result from adaptations in the proper domain of human music. The adaptations provide a foundation for the cultural evolution of music in its actual domain, yielding the diversity of musical forms and musical behaviors found worldwide.

The science of inequality.

Economic inequality is a continuing focus of political debate, and I think a re-post of a brief MindBlog item from 6/2/2014 is relevant:

The May 23 issue of Science Magazine has a large section devoted the origins and analysis of economic inequality. And, the general gist of virtually all the articles is that inequality is here to stay, predicted by social and also simple physical models of exchange. A weekly chaos and complexity discussion group that I attend just this past Tuesday discussed the economic Yard-Sale Model of wealth redistribution, in which power-law-like distributions result even when all individuals are identical and playing by the same rules. In a previous post, I have passed on a simple model illustrated by Clint Sprott, organizer of the seminars.

Predicting results of our presidential election.

I want to pass on an email from retired historian Lou Wangberg, a friend from my Fort Lauderdale period who leads a history discussion group there. He gives links to analyses by The Economist magazine and Mind Matters A.I.

Between now and the election on November 3rd you will see literally countless polls and forecasts. You see, as humans we hate to live with uncertainty. We want to know in advance what is ahead for us. And it is a legitimate question to ask, "Which poll(s) should I pay attention to? "Which poll(s) will be most on target?" the answer is NONE OF THEM. In the end virtually all of them will be wrong for one reason or another. That is why we hold elections. But I have found one that is more sophisticated than the rest and uses 20,000 factors. It also goes day by day so it is interesting to watch. So give this one a try and you will at least have something you can quote in your discussions (arguments) with friends. I'm going to share an additional link that will explain why most predictions are bogus. Enjoy! Here are the links:

The Economist - Forecasting the US elections

Mind Matters - Election Models: Predicting the past is easy - and useless

Democracy in the Balance - Special Issue of Science Magazine

The Sept.4 issue of Science Magazine has a special section of open source perspectives and reviews. A few of the titles:

Racial authoritarianism in U.S. democracy

Campaigns influence election outcomes less than you think

Diversity and prosocial behavior

False equivalencies: Online activism from left to right

The illusion of objectivity enhances political polarization.

From Schwalbe et al. (open source):  

Significance

Political polarization increasingly threatens democratic institutions. The belief that “my side” sees the world objectively while the “other side” sees it through the lens of its biases contributes to this political polarization and accompanying animus and distrust. This conviction, known as the “objectivity illusion,” was strong and persistent among Trump and Clinton supporters in the weeks before the 2016 presidential election. We show that the objectivity illusion predicts subsequent bias and polarization, including heightened partisanship over the presidential debates. A follow-up study showed that both groups impugned the objectivity of a putative blog author supporting the opposition candidate and saw supporters of that opposing candidate as evil.

Abstract

Two studies conducted during the 2016 presidential campaign examined the dynamics of the objectivity illusion, the belief that the views of “my side” are objective while the views of the opposing side are the product of bias. In the first, a three-stage longitudinal study spanning the presidential debates, supporters of the two candidates exhibited a large and generally symmetrical tendency to rate supporters of the candidate they personally favored as more influenced by appropriate (i.e., “normative”) considerations, and less influenced by various sources of bias than supporters of the opposing candidate. This study broke new ground by demonstrating that the degree to which partisans displayed the objectivity illusion predicted subsequent bias in their perception of debate performance and polarization in their political attitudes over time, as well as closed-mindedness and antipathy toward political adversaries. These associations, furthermore, remained significant even after controlling for baseline levels of partisanship. A second study conducted 2 d before the election showed similar perceptions of objectivity versus bias in ratings of blog authors favoring the candidate participants personally supported or opposed. These ratings were again associated with polarization and, additionally, with the willingness to characterize supporters of the opposing candidate as evil and likely to commit acts of terrorism. At a time of particular political division and distrust in America, these findings point to the exacerbating role played by the illusion of objectivity.

Mechanisms of our current political polarization.

I want to point to three sources that provide complimentary perspectives on the origins and maintenance of the extreme Red versus Blue divide in the U.S.:

The first is a freakonomics podcast, with a text version also offered,  describing how Republicans and Democrats form a duopoly analogous to Coke and Pepsi, Intel and AMD, Boeing and Airbus, etc.

"America's Hidden Duopoly - We all know our political system is “broken” — but what if that’s not true? Some say the Republicans and Democrats constitute a wildly successful industry that has colluded to kill off competition, stifle reform, and drive the country apart.  So, what can we do about it?

A second perspective is offered by Yang et al., who provide a "Satisficing" Dynamical Model of why U.S. political parties are so polarized. Here is a summary by Clint Sprott of the Univ. of Wisc. Chaos and Complex Systems Discussion Group:

Basically, it contends that when the parties are too centrist and too inclusive, voters with extreme views find little reason to choose one over the other and either abstain from voting or vote randomly. Thus it is advantageous for the parties to move off center to pick up more of these voters. In the coming election, most people long ago decided which side they are on. Thus all the parties can hope to do at this point is to induce those who lean in their direction to get out and vote. Would mandatory voting reduce polarization? Why is the popular vote usually so close to 50/50?

And finally, a book by Achen and Bartels, "Democracy for Realists: Why Elections Do Not Produce Responsive Government." From the book description:

Democracy for Realists assails the romantic folk-theory at the heart of contemporary thinking about democratic politics and government, and offers a provocative alternative view grounded in the actual human nature of democratic citizens.

Christopher Achen and Larry Bartels deploy a wealth of social-scientific evidence, including ingenious original analyses of topics ranging from abortion politics and budget deficits to the Great Depression and shark attacks, to show that the familiar ideal of thoughtful citizens steering the ship of state from the voting booth is fundamentally misguided. They demonstrate that voters―even those who are well informed and politically engaged―mostly choose parties and candidates on the basis of social identities and partisan loyalties, not political issues. They also show that voters adjust their policy views and even their perceptions of basic matters of fact to match those loyalties. When parties are roughly evenly matched, elections often turn on irrelevant or misleading considerations such as economic spurts or downturns beyond the incumbents' control; the outcomes are essentially random. Thus, voters do not control the course of public policy, even indirectly.

The active grandparent hypothesis - an evolutionary explanation of why and how exercise delays senescence and death.

I recommend that you read an interesting article by Daniel Lieberman in the current issue of Harvard Magazine. Here are a few clips:

The evidence that hunter-gatherers stay physically active for several decades after they stop having children is fundamental for understanding the nature of human aging. Most especially, our uniquely cooperative system of intergenerational cooperation and food-sharing postpones Medawar’s grim shadow. Instead of becoming obsolete, middle-aged and elderly hunter-gatherers bolster their reproductive success by provisioning children and grandchildren, doing childcare, processing food, passing on expertise, and otherwise helping younger generations. Once this novel cooperative strategy—the essence of the hunting and gathering way of life—started to emerge during the Stone Age, natural selection had the chance to select for longevity. According to this theory, hard-working and helpful grandparents who looked out for others and who were blessed with genes that favored a long life had more children and grandchildren, thus passing on those genes. Over time, humans were evidently selected to live longer to be generous, useful grandparents. One version of this idea is known as the Grandmother Hypothesis in recognition of the evidence that grandmothers play especially important roles.

In order to elucidate the links between exercise and aging, I propose a corollary to the Grandmother Hypothesis, which I call the Active Grandparent Hypothesis. According to this idea, human longevity was not only selected for but was also made possible by having to work hard during old age to help as many children, grandchildren, and other younger relatives as possible survive and thrive. That is, while there may have been selection for genes (as yet unidentified) that help humans live past the age of 50, there was also selection for genes that repair and maintain our bodies when we are physically active. As a result, many of the mechanisms that slow aging and extend life are turned on by physical activity, especially as we get older. Human health and longevity are thus extended both by and for physical activity.

While exercise restores most structures (what biologists term homeostasis), in some cases it may create stability by making things even better than before (allostasis). For example, demanding physical activities can increase the strength of bones and muscles, increase cells’ abilities to uptake glucose from the blood, and both augment and replace mitochondria in muscles. In addition, repair mechanisms sometimes overshoot the damage induced by exercise, leading to a net benefit. It’s like scrubbing the kitchen floor so well after a spill that the whole floor ends up being cleaner. All in all, the modest physiological stresses caused by exercise trigger a reparative response yielding a general benefit, a phenomenon sometimes known as hormesis.

Changes as MindBlog's autonomic nervous system ages 11 years

Actually, the original title of this MindBlog post on June 11, 2013 was "Changes as an autonomic nervous system ages 11 years - The "Wild Divine" is a bit less wild." - I'm reviewing old MindBlog posts (very slowly, as it turns out) and in most cases resisting the temptation to re-post even ones I thinks are quite interesting. This personal one really hit me, owever, so I pass it on, wondering how much further the noted decrease in my ability to regulate autonomic nervous system parameters has progressed by age 78:

Just after I retired from being a Univ. of Wisconsin department chair in 2001 I bought a set of finger sensors that fit on one's three middle fingers to report skin conductance and heartbeat to a PC or MAC via an A/D converter. These were part of a package with several CDs that installed a new age game on the computer that lead you through a rich environment of classical greek temples and waterfalls, attended by soothing music, that presented tasks in which you dinked with your own heart rate variability and sympathetic (arousing)/parasympathetic (calming) balance, going alternatively through periods of calm and arousal. I thought it was a hoot, and took the time to go through the "Journey to Wild Divine: passage" and "Journey to Wild Divine: Wisdom Quest."

Some of the current incarnations of these programs have moved to web browsers. Over the years a number of heavy weight new age gurus have signed on with their wares - Deepak Chopra, Dean Ornish, and Andrew Weil (Weil was in my Harvard graduating class...I'm tempted, but I won't burden you with my jaded opinion of this class of entrepreneurs, particularly Mr. Chopra.)

The main point of this post is note my experience on pulling out the finger sensors after 11 years trying the same exercises in their new presentation. What's the difference when this 71 year old tries the same manipulations of calm and arousal that the 60 year old played with with 11 years earlier? In a nutshell, I have less command over heart rate variability, which is lower, as the swings between calm and arousal have less amplitude.

And indeed, this fits with the literature on changes in the autonomic nervous system that occur on aging. If you simply do a google search for "autonomic nervous system and aging" numerous references appear that document how healthy aging is associated with lowered heart rate variability, elevated basal sympathetic nervous activity, and reduction of overall autonomic reactivity of sympathetic and parasympathetic nervous systems. Here is a very recent review, from which I pass on one figure:

Schematic of proposed features associated with the imbalance in the autonomic nervous system during aging. During aging there is a shift in the balance of the autonomic nervous system (ANS) towards the sympathetic nervous system (SNS). This may be influenced by circulating or local brain levels of angiotensin (Ang) II and leptin. The lower activity of the parasympathetic nervous system (PSNS) is proposed to result at least in part from an age-related decline in Angiotensin-(1–7). Lower Angiotensin-(1–7) and higher Ang II or leptin in the brain medulla would predispose to a decline in baroreceptor reflex sensitivity (BRS) for control of heart rate and heart rate variability (HRV), both of which are associated with aging. Moreover, impairments in BRS and HRV can contribute to target organ damage, including metabolic dysfunction, with or without an increase in blood pressure. 

If you're inclined, like Mr. Dylan Thomas, to not "go gently into that good night" you can find numerous sources (example here) on slowing these aging changes, usually by some sort of physical movement or stimulation.

Reconsidering the value of believing in free will.

Nadelhoffer et al. fail to replicate 2008 experiments suggesting that a belief in determinism increases cheating:

A key source of support for the view that challenging people's beliefs about free will may undermine moral behavior is two classic studies by Vohs and Schooler (2008). These authors reported that exposure to certain prompts suggesting that free will is an illusion increased cheating behavior. In the present paper, we report several attempts to replicate this influential and widely cited work. Over a series of five studies (sample sizes of N = 162, N = 283, N = 268, N = 804, N = 982) (four preregistered) we tested the relationship between (1) anti-free-will prompts and free will beliefs and (2) free will beliefs and immoral behavior. Our primary task was to closely replicate the findings from Vohs and Schooler (2008) using the same or highly similar manipulations and measurements as the ones used in their original studies. Our efforts were largely unsuccessful. We suggest that manipulating free will beliefs in a robust way is more difficult than has been implied by prior work, and that the proposed link with immoral behavior may not be as consistent as previous work suggests.

A brief history of risk

Li, Hills, and Hertwig do an open access review with the title of this post. From their introductory paragraph:

...First, we examined how the frequency of the word risk has changed over historical time. Is the construct of risk playing an ever-increasing role in the public discourse, as the sociological notion of a ‘risk society’ suggests? Second, we investigated how the sentiments for the words co-occurring with risk have changed. Are the connotations of risk becoming increasingly ominous? Third, how has the meaning of risk changed relative to close associates such as danger and hazard? Is risk more subject to semantic change? Finally, we decompose the construct of risk into the specific topics with which it has been associated and track those topics over historical time. This brief history of the semantics of risk reveals new and surprising insights—a fourfold increase in frequency, increasingly negative sentiment, a semantic drift toward forecasting and prevention, and a shift away from war toward chronic disease—reflecting the conceptual evolution of risk in the archeological records of public discourse.

Getting the rhythm to suppress Alzheimer's

An interesting brief open source review by Lynne Peeples in PNAS describes experiments on mice and humans showing that visual and sound stimulation in the e.e.g gamma frequency range (30-80 Hertz, or cycles/sec, peaking at 40 Hz) elicits gamma frequency brain oscillation, enhance cognition, and diminishes levels of the amyloid plaques and tau protein tangles associated with Alzheismer's. The article is worth a read, and I pass on just a bit of a background paragraph:

Brain rhythms are known to participate in all forms of cognition. And changes of brain rhythms appear to be implicated in all forms of neurological disease...Growing evidence indicates that neurons in many animals, including humans, can strongly synchronize in the gamma range of frequencies—between 30 and 80 hertz, and peaking around 40 hertz. As far back as a 1955 study of meditating yogis, researchers have associated gamma waves with peak concentration and high levels of cognitive functioning. Studies in the last decade that manipulated brain rhythms in lab animals and humans have confirmed the impact of those rhythms on cognition and disease. Researchers have also found that fewer neurons fire together at this rate in patients with Alzheimer’s disease or other neurological conditions, suggesting that gamma rhythms may play a role in the cognitive impairments associated with such disorders.