The medium really is the message

I recommend that you read a recent Op-Ed piece by Ezra Klein that notes 20th-century media theorists who saw what was coming and tried to warn us. He quotes from Nicholas Carr’s 2010 book “The Shallows: What the Internet Is Doing to Our Brains.”:

Carr’s argument began with an observation, one that felt familiar:

The very way my brain worked seemed to be changing. It was then that I began worrying about my inability to pay attention to one thing for more than a couple of minutes. At first I’d figured that the problem was a symptom of middle-age mind rot. But my brain, I realized, wasn’t just drifting. It was hungry. It was demanding to be fed the way the Net fed it — and the more it was fed, the hungrier it became. Even when I was away from my computer, I yearned to check email, click links, do some Googling. I wanted to be connected.

McLuhan’s view is that mediums matter more than content; it’s the common rules that govern all creation and consumption across a medium that change people and society. Oral culture teaches us to think one way, written culture another. Television turned everything into entertainment, and social media taught us to think with the crowd...All this happens beneath the level of content. CNN and Fox News and MSNBC are ideologically different. But cable news in all its forms carries a sameness: the look of the anchors, the gloss of the graphics, the aesthetics of urgency and threat, the speed, the immediacy, the conflict, the conflict, the conflict.

Klein's (edited) comments on Postman's prophetic 1985 book "Amusing Ourselves to Death":

...the dystopia we must fear is not the totalitarianism of George Orwell’s “1984” but the narcotized somnolence of Aldous Huxley’s “Brave New World.” Television teaches us to expect that anything and everything should be entertaining. But not everything should be entertainment, and the expectation that it will be is a vast social and even ideological change...The border between entertainment and everything else has, and entertainers become the only ones able to fulfill our expectations for politicians....People who were viable politicians in a textual era are locked out of politics because they can not command the screen...Television, he writes, “serves us most ill when it co-opts serious modes of discourse — news, politics, science, education, commerce, religion — and turns them into entertainment packages...the line of Postman’s that holds me is his challenge to the critics who spend their time urging television to be better rather than asking what television is: “The trouble with such people is that they do not take television seriously enough.”

Klein continues:

I have come to think the same of today’s technologists: Their problem is that they do not take technology seriously enough. They refuse to see how it is changing us or even how it is changing them...Over the past decade, the narrative has turned against Silicon Valley. Puff pieces have become hit jobs, and the visionaries inventing our future have been recast as the Machiavellians undermining our present. My frustration with these narratives, both then and now, is that they focus on people and companies, not technologies. I suspect that is because American culture remains deeply uncomfortable with technological critique.

Americans are capitalists, and we believe nothing if not that if a choice is freely made, that grants it a presumption against critique. That is one reason it’s so hard to talk about how we are changed by the mediums we use. That conversation, on some level, demands value judgments. This was on my mind recently, when I heard Jonathan Haidt, a social psychologist who’s been collecting data on how social media harms teenagers, say, bluntly, “People talk about how to tweak it — oh, let’s hide the like counters. Well, Instagram tried — but let me say this very clearly: There is no way, no tweak, no architectural change that will make it OK for teenage girls to post photos of themselves, while they’re going through puberty, for strangers or others to rate publicly.”

What struck me about Haidt’s comment is how rarely I hear anything structured that way. He’s arguing three things. First, that the way Instagram works is changing how teenagers think. It is supercharging their need for approval of how they look and what they say and what they’re doing, making it both always available and never enough. Second, that it is the fault of the platform — that it is intrinsic to how Instagram is designed, not just to how it is used. And third, that it’s bad. That even if many people use it and enjoy it and make it through the gantlet just fine, it’s still bad. It is a mold we should not want our children to pass through.

Or take Twitter. As a medium, Twitter nudges its users toward ideas that can survive without context, that can travel legibly in under 280 characters. It encourages a constant awareness of what everyone else is discussing. It makes the measure of conversational success not just how others react and respond but how much response there is. It, too, is a mold, and it has acted with particular force on some of our most powerful industries — media and politics and technology. These are industries I know well, and I do not think it has changed them or the people in them (including me) for the better.

But what would? I’ve found myself going back to a wise, indescribable book that Jenny Odell, a visual artist, published in 2019, “How to Do Nothing: Resisting the Attention Economy.” In it she suggests that any theory of media must start with a theory of attention. “One thing I have learned about attention is that certain forms of it are contagious,” she writes. She continues:

When you spend enough time with someone who pays close attention to something (if you were hanging out with me, it would be birds), you inevitably start to pay attention to some of the same things. I’ve also learned that patterns of attention — what we choose to notice and what we do not — are how we render reality for ourselves, and thus have a direct bearing on what we feel is possible at any given time. These aspects, taken together, suggest to me the revolutionary potential of taking back our attention.

I think Odell frames both the question and the stakes correctly. Attention is contagious. What forms of it, as individuals and as a society, do we want to cultivate? What kinds of mediums would that cultivation require?

This is anything but an argument against technology, were such a thing even coherent. It’s an argument for taking technology as seriously as it deserves to be taken, for recognizing, as McLuhan’s friend and colleague John M. Culkin put it, “we shape our tools, and thereafter, they shape us.”

There is an optimism in that, a reminder of our own agency. And there are questions posed, ones we should spend much more time and energy trying to answer: How do we want to be shaped? Who do we want to become?

Emotional contagion and prosocial behavior

Keysers et al. do an open source review of studies on emotional contagion and prosocial behavior in rodents, whose brain regions necessary for emotional contagion closely resemble those associated with human empathy:

Rats and mice show robust emotional contagion by aligning their fear and pain to that of others.

Brain regions necessary for emotional contagion in rodents closely resemble those associated with human empathy; understanding the biology of emotional contagion in rodents can thus shed light on the evolutionary origin and mechanisms of human empathy.

Cingulate area 24 in rats and mice contains emotional mirror neurons that map the emotions of others onto the witnesses’ own emotions.

Emotional contagion prepares animals to deal with threats by using others as sentinels; the fact that rodents approach individuals in distress facilitates such contagion.

In some conditions, rats and mice learn to prefer actions that benefit others, with notable individual differences. This effect depends on structures that overlap with those of emotional contagion.

Social Cognitive and Affective Neuroscience - a fascinating journal, many open source articles

Rather than charging in to do separate posts on several of the following fascinating articles, I pass them on for readers to click and choose abstracts and articles as they please.

Neural representation of the parent–child attachment from infancy to adulthood

Inter-brain synchronization is weakened by the introduction of external punishment border

Increased amygdala and decreased frontolimbic resting-state functional connectivity in children with aggressive behavior

Maladaptive self-focused attention and default mode network connectivity: a transdiagnostic investigation across social anxiety and body dysmorphic disorders

Neural correlates of negative emotion processing in subthreshold depression border

A multidimensional examination of psychopathy traits and gray matter volume in adults

Increasing self–other similarity modulates ethnic bias in sensorimotor resonance to others’ pain

Dynamic computation of value signals via a common neural network in multi-attribute decision-making

Harmonics of the social brain

Interesting work from Mague et al. on the brain-wide network in mice that encodes rewarding social experience: 

Highlights

• Machine learning model discovers and integrates circuits into affective brain network 

• Brain-wide network encodes rewarding social experience of individual mice 

• Causal activation of network sub-circuits selectively induces social behavior 

• Social brain network fails to encode individual behavior in a mouse model of autism

Summary

The architecture whereby activity across many brain regions integrates to encode individual appetitive social behavior remains unknown. Here we measure electrical activity from eight brain regions as mice engage in a social preference assay. We then use machine learning to discover a network that encodes the extent to which individual mice engage another mouse. This network is organized by theta oscillations leading from prelimbic cortex and amygdala that converge on the ventral tegmental area. Network activity is synchronized with cellular firing, and frequency-specific activation of a circuit within this network increases social behavior. Finally, the network generalizes, on a mouse-by-mouse basis, to encode individual differences in social behavior in healthy animals but fails to encode individual behavior in a ‘high confidence’ genetic model of autism. Thus, our findings reveal the architecture whereby the brain integrates distributed activity across timescales to encode an appetitive brain state underlying individual differences in social behavior.

The prosocial effect of touching - the Midas touch effect.

Schaefer et al. (open source) examine the neural underpinnings of how light touching enhances prosocial behavior. Their abstract:

Giving and receiving touch are some of the most important social stimuli we exchange in daily life. By touching someone, we can communicate various types of information. Previous studies have also demonstrated that interpersonal touch may affect our altruistic behavior. A classic study showed that customers give bigger tips when they are lightly touched by a waitress, which has been called the Midas touch effect. Numerous studies reported similar effects of touch on different kinds of helping or prosocial behaviors. Here, we aim to examine the neural underpinnings of this effect by employing a functional magnetic resonance imaging approach. While lying in the scanner, participants played different rounds of the dictator game, a measure of prosocial behavior. Before each round, participants were touched (or not touched in the control condition) by an experimenter. We found that touching the hand increased the likeliness to behave prosocial (but not the general liking of control stimuli), thereby confirming the Midas touch effect. The effect was predicted by activity in the primary somatosensory cortex, indicating that the somatosensory cortex here plays a causal role in prosocial behavior. We conclude that the tactile modality in social life may be much more important than previously thought.

The human fear paradox: Affective origins of cooperative care

On the same morning last week that I read a NYTimes essay by Thomas Edsall "The Politics of Fear Show No Sign of Abating" I received an email from the journal Behavioral and Brain Science soliciting reviews on an upcoming article by Tobias Grossmann with an interesting hypothesis on why we humans are so fearful: "The human fear paradox: Affective origins of cooperative care." His 'fearful ape hypothesis' proposes that, in the context of the strong interdependence reflected in cooperative caregiving and provisioning unique to human great ape group life, heightened fearfulness was adaptive. Here I pass on the abstract of Grossmann's piece, and motivated readers can obtain the whole text from me.

Already as infants humans are more fearful than our closest living primate relatives, the chimpanzees. Yet heightened fearfulness is mostly considered maladaptive, as it is thought to increase the risk of developing anxiety and depression. How can this human fear paradox be explained? The fearful ape hypothesis presented herein stipulates that, in the context of cooperative caregiving and provisioning unique to human great ape group life, heightened fearfulness was adaptive. This is because from early in ontogeny fearfulness expressed and perceived enhanced care-based responding and provisioning from, while concurrently increasing cooperation with, mothers and others. This explanation is based on a synthesis of existing research with human infants and children, demonstrating a link between fearfulness, greater sensitivity to and accuracy in detecting fear in others, and enhanced levels of cooperative behaviors. These insights critically advance current evolutionary theories of human cooperation by adding an early-developing affective component to the human cooperative makeup. Moreover, the current proposal has important cultural, societal and health implications, as it challenges the predominant view in WEIRD societies that commonly construe fearfulness as a maladaptive trait, potentially ignoring its evolutionary adaptive functions.

Humans don’t have culture because we’re smart, we’re smart because we have culture.

The title of this post is a sentence taken from the final paragraph of Henrich's Perspective article in Science on the work of Thompson et al. which notes that Thompson et al.'s results

...highlight a deeper point: Humans don’t have culture because we’re smart, we’re smart because we have culture. The selective processes of cultural evolution not only generate more sophisticated practices and technologies but also produce new cognitive tools—algorithms—that make humans better adapted to the ecological and institutional challenges that we confront. Thompson et al.’s results underline the need for the psychological sciences to abandon their implicit reliance on a digital computer metaphor of the mind (hardware versus software) and transform into a historical science that considers not just how cultural evolution shapes what we think (our mental contents) but also how we think [our cognitive processes].

Here I pass on the introductory paragraphs and then the abstract of the Thompson et al. article. Motivated readers can obtain the full text by emailing me.

Reading, counting, cooking, and sailing are just some of the human abilities passed from generation to generation through social learning... Complex abilities like these often depend on learned cognitive algorithms: procedural representations of a problem that coordinate memory, attention, and perception into sequences of useful computations and actions. Accumulation of complex algorithms—from ancient tool-making techniques to bread making, boat building, or horticulture—is central to human adaptation yet challenging to explain because algorithmic concepts can be difficult to discover, communicate, and learn from observation, making them vulnerable to loss. Theories of cultural evolution suggest that human social learning may help overcome this fragility. For example, mathematical models predict that choosing to learn from successful or prestigious individuals can prevent the loss of rare innovations. However, this potential link between sociality and complex abilities is challenging to establish.

We conducted large-scale simulations of cultural evolution with human participants to assess how selective social learning influenced the evolution of cognitive algorithms. Prior research shows that social learning can improve decisions in multiple-choice tasks, perceptual judgments, and search problems and can improve artifacts such as physical structures or computer programs. However, the evolution of cognitive algorithms at the population level has been difficult to study. We developed custom software to recruit large numbers of participants online and organize them into evolving societies facing a common problem. Twenty populations tackled a sequential decision problem... Presented with six images, participants attempted to establish hidden arbitrary orderings using pairwise comparisons. Out-of-order pairs swapped positions when compared. Participants were rewarded for establishing the ordering using fewer comparisons. This task poses a sorting problem, requiring a strategy for executing appropriate sequences of actions, analogous to culturally evolved strategies for making tools or food.

Abstract:

Many human abilities rely on cognitive algorithms discovered by previous generations. Cultural accumulation of innovative algorithms is hard to explain because complex concepts are difficult to pass on. We found that selective social learning preserved rare discoveries of exceptional algorithms in a large experimental simulation of cultural evolution. Participants (N = 3450) faced a difficult sequential decision problem (sorting an unknown sequence of numbers) and transmitted solutions across 12 generations in 20 populations. Several known sorting algorithms were discovered. Complex algorithms persisted when participants could choose who to learn from but frequently became extinct in populations lacking this selection process, converging on highly transmissible lower-performance algorithms. These results provide experimental evidence for hypothesized links between sociality and cognitive function in humans.

The manly art of self-promotion

Exley and Kessler suggest that gender wage gaps may have roots in men being more self-promoting than women:

We run a series of experiments involving over 4,000 online participants and over 10,000 school-aged youth. When individuals are asked to subjectively describe their performance on a male-typed task relating to math and science, we find a large gender gap in self-evaluations. This gap arises when self-evaluations are provided to potential employers, and thus measure self-promotion, and when self-evaluations are not driven by incentives to promote. The gender gap in self-evaluations proves to be persistent and arises as early as the sixth grade. No gender gap arises if individuals are asked about their performance on a more female-typed task.

Reconsidering evidence of moral contagion in online social networks

Burton et al. raise some cautions about recent studies seeming to show that inclusion of emotional terms in social media text messages increases message diffusion. Here is a clip from their text, followed by the article abstract:

...we created an absurd factor for illustrative purposes, what we call XYZ contagion, and tested whether the number of X’s, Y’s and Z’s included in messages’ text predicted diffusion...Our analysis found XYZ contagion to be present in four of our six corpora such that the presence of the letters X, Y and Z predicted an increase in message diffusion: COVID-19 tweets...#MeToo tweets...#MuellerReport tweets...2016 US Election tweets...While there was no positive relationship between the presence of X, Y and Z and message diffusion in the #WomensMarch and Post-Brexit tweets, the finding that XYZ contagion passes a key test of robustness, viz. out-of-sample prediction, demonstrates the potential of large-scale social media datasets to contain spurious correlations

Abstract

The ubiquity of social media use and the digital data traces it produces has triggered a potential methodological shift in the psychological sciences away from traditional, laboratory-based experimentation. The hope is that, by using computational social science methods to analyse large-scale observational data from social media, human behaviour can be studied with greater statistical power and ecological validity. However, current standards of null hypothesis significance testing and correlational statistics seem ill-suited to markedly noisy, high-dimensional social media datasets. We explore this point by probing the moral contagion phenomenon, whereby the use of moral-emotional language increases the probability of message spread. Through out-of-sample prediction, model comparisons and specification curve analyses, we find that the moral contagion model performs no better than an implausible XYZ contagion model. This highlights the risks of using purely correlational evidence from large observational datasets and sounds a cautionary note for psychology’s merge with big data.

How fast people respond to each other is a metric of social connection.

From Templeton et al.:  

Significance

Social connection is critical for our mental and physical health yet assessing and measuring connection has been challenging. Here, we demonstrate that a feature intrinsic to conversation itself—the speed with which people respond to each other—is a simple, robust, and sufficient metric of social connection. Strangers and friends feel more connected when their conversation partners respond quickly. Because extremely short response times (less than 250 ms) preclude conscious control, they provide an honest signal that even eavesdroppers use to judge how well two people “click.”

Abstract

Clicking is one of the most robust metaphors for social connection. But how do we know when two people "click"? We asked pairs of friends and strangers to talk with each other and rate their felt connection. For both friends and strangers, speed in response was a robust predictor of feeling connected. Conversations with faster response times felt more connected than conversations with slower response times, and within conversations, connected moments had faster response times than less-connected moments. This effect was determined primarily by partner responsivity: People felt more connected to the degree that their partner responded quickly to them rather than by how quickly they responded to their partner. The temporal scale of these effects (less than 250 ms) precludes conscious control, thus providing an honest signal of connection. Using a round-robin design in each of six closed networks, we show that faster responders evoked greater feelings of connection across partners. Finally, we demonstrate that this signal is used by third-party listeners as a heuristic of how well people are connected: Conversations with faster response times were perceived as more connected than the same conversations with slower response times. Together, these findings suggest that response times comprise a robust and sufficient signal of whether two minds “click.”

Children universally across societies enforce conventional norms but in culturally variable ways

From Kanngiesser et al. in PNAS:

Humans, as compared with other animals, create and follow conventional norms that determine how we greet each other, dress, or play certain games. Conventional norms are universal in all human societies, but it is an open question whether individuals in all societies also actively enforce conventional norms when others in their group break them. We investigated third-party enforcement of conventional norms in 5- to 8-y-old children (n = 376) from eight diverse small-scale and large-scale societies. Children learned the rules for playing a new sorting game and then, observed a peer who was apparently breaking them. Across societies, observer children intervened frequently to correct their misguided peer (i.e., more frequently than when the peer was following the rules). However, both the magnitude and the style of interventions varied across societies. Detailed analyses of children’s interactions revealed societal differences in children’s verbal protest styles as well as in their use of actions, gestures, and nonverbal expressions to intervene. Observers’ interventions predicted whether their peer adopted the observer’s sorting rule. Enforcement of conventional norms appears to be an early emerging human universal that comes to be expressed in culturally variable ways.

The Power of Us

A recent New York Times essay by Jon Mooallem, "Is life better when we're together?" is worth a read, and references work of Packer and Van Bavel described in their new book "The Power of Us." Their experiments, a continuation of work started by psychologist Henri Tafjel in the 1970s, illustrate how our social brains are programmed to organize us into "us" and "them" groups on the basis of sometimes completely arbitrary and trivial criteria, as in assigning a study group of subjects into groups A and B on the basis of a coin toss.  Tafjel's work is also referenced in another excellent article by Elizabeth Kolbert in The New Yorker, "How Politics Got So Polarized."  She reviews a number of recent books in this area, and also notes the phenomenon of "false polarization" - views of the extremes predominate as the moderate majority of people withdraw from the fray of commentary.

Here are some clips from the Mooallem article, the first noting Tafjel's experiments on high school students in Bristol, England.

...biases locked in right away. Overwhelmingly, people in Dr. Tajfel’s experiment gave more of the money he put at their disposal to members of their own group than the other. Moreover, they were bent on creating as large a disparity as possible, even when offered the option of maximizing the amount of money for everyone, at no cost. Their behavior seemed vindictive, “a clear case of gratuitous discrimination,” Dr. Tajfel wrote.

Since then, other researchers have run their own minimal group experiments, pushing those findings further. Dr. Packer and Dr. Van Bavel have split people into leopards and tigers, for example. Others have gone maximally minimal and divided people into group A and group B. Still, the pride — the readiness to connect — is always there. When you tell people they’re in group A, Dr. Packer says, those people are reliably psyched to be in group A. Stick leopard people in a brain imaging machine and show them a picture of a stranger, and their brain activity changes if they know that the stranger is a leopard person, too. Their positivity toward other leopard people increases and even supersedes racial biases that cut the other way.

Dr. Packer and Dr. Van Bavel call the minimal group studies “among the most important studies in the history of psychology.” They demonstrate that “the human sense of self — your gravitational center — does not stay in the same place. With a flip of a coin, people constructed entirely new identities in a matter of minutes.”...The rewards of this kind of connectedness wind up driving all kinds of wonderful human behavior, sometimes less obviously than we’d assume.

But it also leads to the behaviors shown by the insurrections of the Jan. 6, 2021 attack on the U.S. Capitol.

It’s hard to imagine more antisocial behavior than attempting to undo a democratic election with mayhem and violence. But the insurrectionists were doing it together, and pretty joyously, it seemed — snapping selfies, posting them to Facebook with stupid jokes in real time. It was, within their community, a prosocial activity, too.

When a system appears to be malfunctioning, indifferent, reckless or corrupt, that’s a kind of disaster, and people are likely to come together and respond, for better or worse...Some will be volunteers, and some will be vigilantes. But both may be reacting to a similar feeling of free fall, of tumbling. This doesn’t make them morally equivalent; in the end, morality is what keeps them from being equivalent. I know it’s important to keep drawing that distinction, to keep calling it out. I also know it’s not enough.

In praise of Sheeple - why we shouldn't always think for ourselves

A friend pointed out this interesting article by Ian Leslie, which I recommend that you read. I pass on a few clips at the end of his exposition:

...the human instinct to copy rather than think for ourselves is good for us, up to a point. Cultural anthropologists have done the most to establish that our instinct to copy parents and peers helps us to learn, to get along, to organise, to bond, and ultimately to build the shared behaviours that enable us to survive and progress. They’ve discovered that compared to other primates humans “over-imitate”: we copy even when there’s no reason to.

In a much-replicated experiment, a complicated-looking box is presented to chimps and the researchers demonstrate how to access a bit of food inside. They include some unnecessary steps: tapping the box three times, fiddling with a bolt, whatever. The chimps quickly work out all they need to do is pull a door and grab the food, and ignore the superfluous actions. Do this experiment with very small humans, however, and the kids copy all the actions. The chimps are more efficient and in a way more ‘rational’ but it’s the other primate which has built cities, ships and cathedrals.

Traditions we don’t understand ought not to be dismissed too quickly, since the collective intelligence of the past dwarves our own. In The Secret of Our Success, the anthropologist Joseph Henrich argues that individual humans are not nearly as smart as we think and that it is culture that makes us a successful species. The Naskapi, a foraging tribe from north-eastern Canada, hunt caribou. They have to decide where to hunt, which isn’t straightforward because if they visit one location too often the caribou know to stay away. The best hunting strategy therefore requires randomisation.

But individuals like to think they’re smart and left to their own devices, Naskapi hunters probably wouldn’t be satisfied with setting out in a random direction every day; they’d come up with brilliant plans which proved to be disastrous. Tradition saves them. To decide where to go, the hunters use a divination ritual which involves heating a caribou shoulder blade over hot coals until cracks and spots start to appear on it; the resulting pattern is then used as a map. In a sense it’s a mindless ritual, but it’s also a randomising device which helps the hunters overcome their decision-making biases.

Here’s what I like about the dupes. When everyone around them behaved in a certain way, their first thought wasn’t “I must be smarter than them”. It was, “They must know something I don’t”. There is an admirable humility to that, even if, in this case, it led them to say or do something absurd. The ability of individual humans to think for ourselves is crucial to progress; equally crucial is that we trust, sometimes unthinkingly, in judgements made by others, alive or dead. Societies where too few people are willing to question norms and traditions tend to stagnate and to perpetuate injustices. But there is a positive side to conformism, too. Just as in an imaginary nightclub on fire there’s a good chance that a passing group will lead you to an exit, there’s a good chance that whatever the people around you say is right, is right, even if you don’t fully understand why yet. Society functions best when we’re sheepish.

What is a DAO? Who needs humans?

A DAO is a Decentralised Autonomous Organisation. My son pointed out this intriguing and also somewhat terrifying video to me. Like Mark Zuckerberg's corporate "Meta" fantasies another step towards tearing our evolved biolgical bodies and social brains away from the organic tactile contacts with each other for which they were designed.

 

The Science of Hugs?

Schultz describes an entertaining bit of work pursuing the obvious done by Düren et.al. Guys hugging each other use their arms differently than women do, more frequently doing a crisscross hug (on the left) than a neck-waist hug (on the right), most likely because the neck-waist hug feels a bit more intimate.

Without prompting the students on how to hug, the researchers found the crisscross style was more common, accounting for 66 out of 100 hugs. The preference for crisscross was especially prevalent in pairs of men, with 82% of 28 observed pairs opting for the style. Neither emotional closeness nor height had significant effects on the style of hugging; however, the researchers note that most participants were relatively close in height, and they guess that neck-waist might be more common when heights differ more drastically.

Online spread of false information depends on cascade size

Juul and Ugander do an analysis of factors that influence the spread of false news, finding a central role for cascade size and suggesting that to limit the spread of false news, it may be enough to focus on reducing the mean “infectiousness” of the information.  

Significance

Do different types of information spread differently online? In recent years, studies have sought answers to such questions by comparing statistical properties of network paths taken by different kinds of content diffusing online. Here, we demonstrate the importance of controlling for correlations between properties being compared. In particular, we show that previously reported structural differences between diffusion paths of false and true news on Twitter disappear when comparing only cascades of the same size; differences between diffusion paths of images, videos, news, and petitions persist. Paired with a theoretical analysis of diffusion processes, our results suggest that, in order to limit the spread of false news, it may be enough to focus on reducing the mean “infectiousness” of the information.

Abstract

Do some types of information spread faster, broader, or further than others? To understand how information diffusions differ, scholars compare structural properties of the paths taken by content as it spreads through a network, studying so-called cascades. Commonly studied cascade properties include the reach, depth, breadth, and speed of propagation. Drawing conclusions from statistical differences in these properties can be challenging, as many properties are dependent. In this work, we demonstrate the essentiality of controlling for cascade sizes when studying structural differences between collections of cascades. We first revisit two datasets from notable recent studies of online diffusion that reported content-specific differences in cascade topology: an exhaustive corpus of Twitter cascades for verified true- or false-news content by Vosoughi et al. [S. Vosoughi, D. Roy, S. Aral. Science 359, 1146–1151 (2018)] and a comparison of Twitter cascades of videos, pictures, news, and petitions by Goel et al. [S. Goel, A. Anderson, J. Hofman, D. J. Watts. Manage. Sci. 62, 180–196 (2016)]. Using methods that control for joint cascade statistics, we find that for false- and true-news cascades, the reported structural differences can almost entirely be explained by false-news cascades being larger. For videos, images, news, and petitions, structural differences persist when controlling for size. Studying classical models of diffusion, we then give conditions under which differences in structural properties under different models do or do not reduce to differences in size. Our findings are consistent with the mechanisms underlying true- and false-news diffusion being quite similar, differing primarily in the basic infectiousness of their spreading process.

Volatile hexadecanal emitted by babies could make men more docile and women more aggressive

Interesting observations from Mishor et al.:

In terrestrial mammals, body volatiles can effectively trigger or block conspecific aggression. Here, we tested whether hexadecanal (HEX), a human body volatile implicated as a mammalian-wide social chemosignal, affects human aggression. 

Using validated behavioral paradigms, we observed a marked dissociation: Sniffing HEX blocked aggression in men but triggered aggression in women. Next, using functional brain imaging, we uncovered a pattern of brain activity mirroring behavior: In both men and women, HEX increased activity in the left angular gyrus, an area implicated in perception of social cues. HEX then modulated functional connectivity between the angular gyrus and a brain network implicated in social appraisal (temporal pole) and aggressive execution (amygdala and orbitofrontal cortex) in a sex-dependent manner consistent with behavior: increasing connectivity in men but decreasing connectivity in women. These findings implicate sex-specific social chemosignaling at the mechanistic heart of human aggressive behavior.

From the author's discussion:

....what behavioral setting could underlie selection for a body volatile that increases aggression in women but decreases it in men? Or in other words, what could be the ecological relevance of these results? In this respect, we call attention to the setting of infant rearing. Parents across cultures are encouraged to sniff their babies, an action that activates brain reward circuits in women. Our results imply that sniffing babies may increase aggression in mothers but decrease aggression in fathers. Whereas maternal aggression has a direct positive impact on offspring survival in the animal world, paternal aggression has a negative impact on offspring survival. This is because maternal aggression (also termed maternal defense behavior) is typically directed at intruders, yet paternal aggression, and more so nonpaternal male aggression, is often directed at the offspring themselves. If babies had a mechanism at their disposal that increased aggression in women but decreased it in men, this would likely increase their survival. With the hypothesis in mind that HEX provides babies with exactly such a mechanism, we first note that infant rearing is the one social setting where humans have extensive exposure to conspecific feces, a rich source of HEX. We also turned to a recently published analysis of baby-head volatiles, yet in contrast to our hypothesis, this report did not mention HEX. We turned to the authors of that report, who explained that the published analysis was not tuned to the near semivolatile range of HEX. With our question in mind, they (now coauthors T.U. and M.O.) sampled an additional 19 babies, using gas chromatography (GC) × GC–mass spectrometry, and observed that HEX is one of the most abundant baby-head volatiles...

People listening to the same story synchronize their heart rates.

Several studies have shown that people paying attention to the same videos or listening to the same stories show similar brain activity, as measured by electroencephalogram (EEG). Electrocardiogram (EKG) measurements are experimentally much easier to perform. Pérez et al. now show that heart rates of participants of their study measured by EKG tended to speed up or slow down at the same points in the story, demonstrating that conscious processing of narrative stimuli synchronizes heart rate between individuals. Here is their abstract:  

Highlights

• Narrative stimuli can synchronize fluctuations of heart rate between individuals 

• This interpersonal synchronization is modulated by attention and predicts memory 

• These effects on heart rate cannot be explained by modulation of respiratory patterns 

• Synchrony is lower in patients with disorders of consciousness

Summary

Heart rate has natural fluctuations that are typically ascribed to autonomic function. Recent evidence suggests that conscious processing can affect the timing of the heartbeat. We hypothesized that heart rate is modulated by conscious processing and therefore dependent on attentional focus. To test this, we leverage the observation that neural processes synchronize between subjects by presenting an identical narrative stimulus. As predicted, we find significant inter-subject correlation of heart rate (ISC-HR) when subjects are presented with an auditory or audiovisual narrative. Consistent with our hypothesis, we find that ISC-HR is reduced when subjects are distracted from the narrative, and higher ISC-HR predicts better recall of the narrative. Finally, patients with disorders of consciousness have lower ISC-HR, as compared to healthy individuals. We conclude that heart rate fluctuations are partially driven by conscious processing, depend on attentional state, and may represent a simple metric to assess conscious state in unresponsive patients.

Secure human attachment can promote support for climate change mitigation

From Misa et al.: 

Significance

Attachment theory focuses on the primal form of emotional bonding between humans. Attachment is conceptualized as an innate behavioral system aimed at safeguarding against potential threats by assuring proximity to caring and supportive others. When individuals feel securely attached (thus feeling less threatened in most situations), the activation of the caregiving behavioral system (concern for others) is facilitated. With this research, we show that priming attachment security influences how much people care about and accept climate change via an increased empathy for humanity. Furthermore, we demonstrate that this activation bypasses the resistance of politically conservative individuals to mitigate climate change. Overall, we show that attachment security–based stimuli can inform intervention and policymaking strategies to help fight climate change.

Abstract

Attachment theory is an ethological approach to the development of durable, affective ties between humans. We propose that secure attachment is crucial for understanding climate change mitigation, because the latter is inherently a communal phenomenon resulting from joint action and requiring collective behavioral change. Here, we show that priming attachment security increases acceptance (Study 1: n = 173) and perceived responsibility toward anthropogenic climate change (Study 2: n = 209) via increased empathy for others. Next, we demonstrate that priming attachment security, compared to a standard National Geographic video about climate change, increases monetary donations to a proenvironmental group in politically moderate and conservative individuals (Study 3: n = 196). Finally, through a preregistered field study conducted in the United Arab Emirates (Study 4: n = 143,558 food transactions), we show that, compared to a message related to carbon emissions, an attachment security–based message is associated with a reduction in food waste. Taken together, our work suggests that an avenue to promote climate change mitigation could be grounded in core ethological mechanisms associated with secure attachment.

Seeing others react to threats triggers our own internal threat responses.

From Haaker et al. (open source): 

Significance

Social transmission of threat information by observation is effective in humans and other animals. However, it is unknown if such observation of others’ reacting to threats can retrieve memories that have been previously learned through direct, firsthand aversive experiences. Here, we show concordantly in humans and rats that observing a conspecific’s reactions to a threat is sufficient to recover associative memories of direct, firsthand aversive experiences, measured as conditioned threat responses (physiological responses and defensive behavior) in the observer. The reinstatement of threat responses by observation of others is specific to the context that is observed as being dangerous. Our findings provide cross-species evidence that observation of others’ threat reactions can recover associative memories of direct, firsthand aversive experiences.

Abstract

Information about dangers can spread effectively by observation of others’ threat responses. Yet, it is unclear if such observational threat information interacts with associative memories that are shaped by the individual’s direct, firsthand experiences. Here, we show in humans and rats that the mere observation of a conspecific’s threat reactions reinstates previously learned and extinguished threat responses in the observer. In two experiments, human participants displayed elevated physiological responses to threat-conditioned cues after observational reinstatement in a context-specific manner. The elevation of physiological responses (arousal) was further specific to the context that was observed as dangerous. An analogous experiment in rats provided converging results by demonstrating reinstatement of defensive behavior after observing another rat’s threat reactions. Taken together, our findings provide cross-species evidence that observation of others’ threat reactions can recover associations previously shaped by direct, firsthand aversive experiences. Our study offers a perspective on how retrieval of threat memories draws from associative mechanisms that might underlie both observations of others’ and firsthand experiences.