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neurobiological evidence of pulvinar neuron responses to a potential predation threat is convincing, Dobson noted more work is needed to support a role for snakes in primate evolution.

“fear module” in the primate brain—a construct that enables “quick responses to stimuli that signal danger, such as predators and threatening faces”

“Since they [the authors] haven’t—to my knowledge—tested the same stimuli on various other parts of the visual system, they don’t have evidence that these putatively selective cells are a specialization of the ‘fear module’ at all,”

There are plenty of theories, of course, especially regarding why: increasingly complex social networks, a culture built around tool use and collaboration, the challenge of adapting to a mercurial and often harsh climate

Although these possibilities are fascinating, they are extremely difficult to test.

Although it makes up only 2 percent of body weight, the human brain consumes a whopping 20 percent of the body’s total energy at rest. In contrast, the chimpanzee brain needs only half that.

contrary to long-standing assumptions, larger mammalian brains do not always have more neurons, and the ones they do have are not always distributed in the same way.

The human brain has 86 billion neurons in all: 69 billion in the cerebellum, a dense lump at the back of the brain that helps orchestrate basic bodily functions and movement; 16 billion in the cerebral cortex, the brain’s thick corona and the seat of our most sophisticated mental talents, such as self-awareness, language, problem solving and abstract thought; and 1 billion in the brain stem and its extensions into the core of the brain

In contrast, the elephant brain, which is three times the size of our own, has 251 billion neurons in its cerebellum, which helps manage a giant, versatile trunk, and only 5.6 billion in its cortex

primates evolved a way to pack far more neurons into the cerebral cortex than other mammals did

The great apes are tiny compared to elephants and whales, yet their cortices are far denser: Orangutans and gorillas have 9 billion cortical neurons, and chimps have 6 billion. Of all the great apes, we have the largest brains, so we come out on top with our 16 billion neurons in the cortex.

“What kinds of mutations occurred, and what did they do? We’re starting to get answers and a deeper appreciation for just how complicated this process was.”

there was a strong evolutionary pressure to modify the human regulatory regions in a way that sapped energy from muscle and channeled it to the brain.

Accounting for body size and weight, the chimps and macaques were twice as strong as the humans. It’s not entirely clear why, but it is possible that our primate cousins get more power out of their muscles than we get out of ours because they feed their muscles more energy. “Compared to other primates, we lost muscle power in favor of sparing energy for our brains,” Bozek said. “It doesn’t mean that our muscles are inherently weaker. We might just have a different metabolism.

a pioneering experiment. Not only were they going to identify relevant genetic mutations from our brain’s evolutionary past, they were also going to weave those mutations into the genomes of lab mice and observe the consequences.

Silver and Wray introduced the chimpanzee copy of HARE5 into one group of mice and the human edition into a separate group. They then observed how the embryonic mice brains grew.

After nine days of development, mice embryos begin to form a cortex, the outer wrinkly layer of the brain associated with the most sophisticated mental talents. On day 10, the human version of HARE5 was much more active in the budding mice brains than the chimp copy, ultimately producing a brain that was 12 percent larger

“It wasn’t just a couple mutations and—bam!—you get a bigger brain. As we learn more about the changes between human and chimp brains, we realize there will be lots and lots of genes involved, each contributing a piece to that. The door is now open to get in there and really start understanding. The brain is modified in so many subtle and nonobvious ways.”

As recent research on whale and elephant brains makes clear, size is not everything, but it certainly counts for something. The reason we have so many more cortical neurons than our great-ape cousins is not that we have denser brains, but rather that we evolved ways to support brains that are large enough to accommodate all those extra cells.

There’s a danger, though, in becoming too enamored with our own big heads. Yes, a large brain packed with neurons is essential to what we consider high intelligence. But it’s not sufficient

No matter how large the human brain grew, or how much energy we lavished upon it, it would have been useless without the right body. Three particularly crucial adaptations worked in tandem with our burgeoning brain to dramatically increase our overall intelligence: bipedalism, which freed up our hands for tool making, fire building and hunting; manual dexterity surpassing that of any other animal; and a vocal tract that allowed us to speak and sing.

Human intelligence, then, cannot be traced to a single organ, no matter how large; it emerged from a serendipitous confluence of adaptations throughout the body. Despite our ongoing obsession with the size of our noggins, the fact is that our intelligence has always been so much bigger than our brain.

To be sure, the researchers acknowledge, their hypothesis is a work in progress.

Once he gets the fruit, his dopamine stops. The good feeling will be gone as soon as it's metabolized. To get more, he will have to do more.  Natural selection produced a brain that feels good when it works toward a goal.

The monkey's brain weighs the evidence based on past experience. The fruit he scored in the past triggered dopamine that paved neural pathways and trigger his dopamine today. But the pain of past setbacks built cortisol pathways that alert him to the risk of setbacks today.

Your brain evolved to stimulate them by takig action to meet your needs. Just taking steps toward skill building gets your happy chemicals flowing once you've built the circuits that kick-start the process.

different kind of motivation comes from serotonin. Let's say our monkey's fruit is snatched by a bigger, stronger monkey when he finally gets to the top of the tree. Experience has taught him that bigger monkeys cause pain, and falling from a tree causes pain.

A surge of serotonin causes this feeling. Experience teaches a monkey to determine when he is in the superior position and when he is in the inferior position.

These words horrify us in today's culture, but a monkey would starve to death if it always saw itself as inferior. It has to feel confident to go for it some of the time. Serotonin creates that confidence.

You may say that monkeys should cooperate, share the bananas, or leave the bananas for the needy. By saying these things, you mark yourself as a superior person in today's society. You are just seeking serotonin in the modern way. You stimulate oxytocin when your self-restraint helps you belong

 Oxytocin causes the good feeling of social solidarity, and low oxytocin warns your inner mammal that you're in immediate danger. Our brains are constantly aware of potential threats to our social bonds. Competition can threaten your bonds, but it can also strengthen them. Superior skills can bring recognition that reassures you of social acceptance and belonging. Secure social bonds feel good because they stimulate oxytocin.

Your inner mammal is always looking for ways to stimulate your dopamine, serotonin and oxytocin.

Your mirror neurons stimulate dopamine when you see other people get rewards

first new fossil was unearthed in 2011, when the team found a molar belonging to the oldest known Old World monkey or cercopithecoid, which they named Nsungwepithecus gunnelli. A year later and 15 kilometers away, they found the oldest known remains of a hominoid or “ape”—a jawbone and four teeth belonging to a new species that they dubbed Rukwapithecus fleaglei. 

fossils from the late Oligocene are rare, partly because there are few deposits of the right age and they tend to be covered in thick vegetation.

“That implies that the hominoid-cercopithecoid divergence was well underway.”

the new discoveries expand the range of Oligocene primates from a handful of fossils in Kenya and Saudi Arabia, to the more southerly country of Tanzania. This location also suggests that the ape and Old World monkey lineages arose against a background of great geological upheaval. By the time Rukwapithecus and Nsungwepithecus appeared, the climate was warming and the flat Tanzanian landscape had already begun to fragment into mountains, deep rifts, and lakes, creating the beginnings of the Eastern African Rift. These changes could have created many new habitats, and fueled the diversification of the local primates.

were expecting [similar] fossils to occur in a more tectonically stable landscape, and were searching to the north in Kenya, Libya, and Egypt,”

“The Rukwa Rift Basin Project has succeeded in destroying those preconceived notions and opens many new possibilities.”

We suspect that by 25 million years ago, there were already several independent lineages of both apes and monkeys in Africa, but paleontologists just haven’t found their fossil remains yet. We are soon headed back to the field to try to find some more!”

Globally, the numbers can be even worse, and the stakes often higher. “Say a person comes into the hospital in Sierra Leone with a fever and flulike symptoms,” DeRisi says. “After a few days, or a week, they die. What caused that illness? Most of the time, we never find out. Because if the cause isn’t something that we can culture and test for” — like hepatitis, or strep throat — “it basically just stays a mystery.”

It would be better, DeRisi says, to watch for rare cases of mystery illnesses in people, which often exist well before a pathogen gains traction and is able to spread.

Based on a retrospective analysis of blood samples, scientists now know that H.I.V. emerged nearly a dozen times over a century, starting in the 1920s, before it went global.

Zika was a relatively harmless illness before a single mutation, in 2013, gave the virus the ability to enter and damage brain cells.

The beauty of this approach” — running blood samples from people hospitalized all over the world through his system, known as IDseq — “is that it works even for things that we’ve never seen before, or things that we might think we’ve seen but which are actually something new.”

In this scenario, an undiscovered or completely new virus won’t trigger a match but will instead be flagged. (Even in those cases, the mystery pathogen will usually belong to a known virus family: coronaviruses, for instance, or filoviruses that cause hemorrhagic fevers like Ebola and Marburg.)

And because different types of bacteria require specific conditions in order to grow, you also need some idea of what you’re looking for in order to find it.

The same is true of genomic sequencing, which relies on “primers” designed to match different combinations of nucleotides (the building blocks of DNA and RNA).

Even looking at a slide under a microscope requires staining, which makes organisms easier to see — but the stains used to identify bacteria and parasites, for instance, aren’t the same.

The practice that DeRisi helped pioneer to skirt this problem is known as metagenomic sequencing

Unlike ordinary genomic sequencing, which tries to spell out the purified DNA of a single, known organism, metagenomic sequencing can be applied to a messy sample of just about anything — blood, mud, seawater, snot — which will often contain dozens or hundreds of different organisms, all unknown, and each with its own DNA. In order to read all the fragmented genetic material, metagenomic sequencing uses sophisticated software to stitch the pieces together by matching overlapping segments.

The assembled genomes are then compared against a vast database of all known genomic sequences — maintained by the government-run National Center for Biotechnology Information — making it possible for researchers to identify everything in the mix

Traditionally, the way that scientists have identified organisms in a sample is to culture them: Isolate a particular bacterium (or virus or parasite or fungus); grow it in a petri dish; and then examine the result under a microscope, or use genomic sequencing, to understand just what it is. But because less than 2 percent of bacteria — and even fewer viruses — can be grown in a lab, the process often reveals only a tiny fraction of what’s actually there. It’s a bit like planting 100 different kinds of seeds that you found in an old jar. One or two of those will germinate and produce a plant, but there’s no way to know what the rest might have grown into.

Such studies have revealed just how vast the microbial world is, and how little we know about it

“The selling point for researchers is: ‘Look, this technology lets you investigate what’s happening in your clinic, whether it’s kids with meningitis or something else,’” DeRisi said. “We’re not telling you what to do with it. But it’s also true that if we have enough people using this, spread out all around the world, then it does become a global network for detecting emerging pandemics

One study found more than 1,000 different kinds of viruses in a tiny amount of human stool; another found a million in a couple of pounds of marine sediment. And most were organisms that nobody had seen before.

After the Biohub opened in 2016, one of DeRisi’s goals was to turn metagenomics from a rarefied technology used by a handful of elite universities into something that researchers around the world could benefit from

metagenomics requires enormous amounts of computing power, putting it out of reach of all but the most well-funded research labs. The tool DeRisi created, IDseq, made it possible for researchers anywhere in the world to process samples through the use of a small, off-the-shelf sequencer, much like the one DeRisi had shown me in his lab, and then upload the results to the cloud for analysis.

he’s the first to make the process so accessible, even in countries where lab supplies and training are scarce. DeRisi and his team tested the chemicals used to prepare DNA for sequencing and determined that using as little as half the recommended amount often worked fine. They also 3-D print some of the labs’ tools and replacement parts, and offer ongoing training and tech support

The metagenomic analysis itself — normally the most expensive part of the process — is provided free.

But DeRisi’s main innovation has been in streamlining and simplifying the extraordinarily complex computational side of metagenomics

IDseq is also fast, capable of doing analyses in hours that would take other systems weeks.

“What IDseq really did was to marry wet-lab work — accumulating samples, processing them, running them through a sequencer — with the bioinformatic analysis,”

“Without that, what happens in a lot of places is that the researcher will be like, ‘OK, I collected the samples!’ But because they can’t analyze them, the samples end up in the freezer. The information just gets stuck there.”

Meningitis itself isn’t a disease, just a description meaning that the tissues around the brain and spinal cord have become inflamed. In the United States, bacterial infections can cause meningitis, as can enteroviruses, mumps and herpes simplex. But a high proportion of cases have, as doctors say, no known etiology: No one knows why the patient’s brain and spinal tissues are swelling.

When Saha and her team ran the mystery meningitis samples through IDseq, though, the result was surprising. Rather than revealing a bacterial cause, as expected, a third of the samples showed signs of the chikungunya virus — specifically, a neuroinvasive strain that was thought to be extremely rare. “At first we thought, It cannot be true!” Saha recalls. “But the moment Joe and I realized it was chikungunya, I went back and looked at the other 200 samples that we had collected around the same time. And we found the virus in some of those samples as well.”

Until recently, chikungunya was a comparatively rare disease, present mostly in parts of Central and East Africa. “Then it just exploded through the Caribbean and Africa and across Southeast Asia into India and Bangladesh,” DeRisi told me. In 2011, there were zero cases of chikungunya reported in Latin America. By 2014, there were a million.

Chikungunya is a mosquito-borne virus, but when DeRisi and Saha looked at the results from IDseq, they also saw something else: a primate tetraparvovirus. Primate tetraparvoviruses are almost unknown in humans, and have been found only in certain regions. Even now, DeRisi is careful to note, it’s not clear what effect the virus has on people. “Maybe it’s dangerous, maybe it isn’t,” DeRisi says. “But I’ll tell you what: It’s now on my radar.

it reveals a landscape of potentially dangerous viruses that we would otherwise never find out about. “What we’ve been missing is that there’s an entire universe of pathogens out there that are causing disease in humans,” Imam notes, “ones that we often don’t even know exist.”

“The plan was, Let’s let researchers around the world propose studies, and we’ll choose 10 of them to start,” DeRisi recalls. “We thought we’d get, like, a couple dozen proposals, and instead we got 350.”

Metagenomic sequencing is especially good at what scientists call “environmental sampling”: identifying, say, every type of bacteria present in the gut microbiome, or in a teaspoon of seawater.

“When you draw blood from someone who has a fever in Ghana, you really don’t know very much about what would normally be in their blood without fever — let alone about other kinds of contaminants in the environment. So how do you interpret the relevance of all the things you’re seeing?”

Such criticisms have led some to say that metagenomics simply isn’t suited to the infrastructure of developing countries. Along with the problem of contamination, many labs struggle to get the chemical reagents needed for sequencing, either because of the cost or because of shipping and customs holdups

we’re less likely to be caught off-guard. “With Ebola, there’s always an issue: Where’s the virus hiding before it breaks out?” DeRisi explains. “But also, once we start sampling people who are hospitalized more widely — meaning not just people in Northern California or Boston, but in Uganda, and Sierra Leone, and Indonesia — the chance of disastrous surprises will go down. We’ll start seeing what’s hidden.”

Since antiquity, this idea had been considered but rejected in favor of the traditional (geostatic and geocentric) thesis that the earth stands still at the center of the universe.

The objections to the geokinetic and heliocentric idea involved astronomical observations, the physics of motion, biblical passages, and epistemological principles (e.g., the reliability of human senses, which reveal a stationary earth)

The Inquisition launched an investigation. Galileo’s writings were evaluated and other witnesses interrogated. The charges against Galileo were unsubstantiated. However, the officials started worrying about the status of heliocentrism and consulted a committee of experts.

These discoveries did not conclusively prove Copernicanism, but provided new evidence in its favor and refutations of some old objections.

Galileo became more explicit in his pursuit of heliocentrism, and this soon got him into trouble.

In February-March 1615, one Dominican friar filed a written complaint against him, and another one testified in person in front of the Roman Inquisition. They accused Galileo of heresy, for believing in the earth’s motion, which contradicted Scripture, e.g., the miracle in Joshua 10:12-13.

Copernicus did not really refute these objections, but he elaborated a novel and important astronomical argument. Thus, Copernicanism attracted few followers. At first, Galileo himself was not one of them, although he was interested because his new physics enabled him to answer the mechanical objections.

On February 24, 1616, the consultants unanimously reported the assessment that heliocentrism was philosophically (i.e., scientifically) false and theologically heretical or at least erroneous.

The following day, the Inquisition, presided by Pope Paul V, considered the case. Although it did not endorse the heresy recommendation, it accepted the judgments of scientific falsity and theological error, and decided to prohibit the theory.

the Church was going to declare the idea of the earth’s motion false and contrary to Scripture, and so this theory could not be held or defended. Galileo agreed to comply.

Without mentioning Galileo, it publicly declared the earth’s motion false and contrary to Scripture. It prohibited the reading of Copernicus’s Revolutions, and banned a book published in 1615 by Paolo Antonio Foscarini; he had argued that the earth’s motion was probably true, and certainly compatible with Scripture.

The 1616 condemnation of Copernicanism was bad enough for the relationship between science and religion, but the problems were compounded by Galileo’s trial 17 years later.

Galileo kept quiet until 1623, when a new pope was elected, Urban VIII, who was a great admirer of Galileo.

The Inquisition summoned him to Rome, and the trial proceedings lasted from April to June 1633. He was found guilty of suspected heresy, for defending the earth’s motion, and thus denying the authority of Scripture.

“Suspected heresy” was not as serious a religious crime as “formal heresy,” and so his punishment was not death by being burned at the stake, but rather house arrest and the banning of the Dialogue.

The Church’s condemnation of Copernicanism and Galileo became the iconic illustration of the problematic relationship between science and religion.

This controversy will probably not end any time soon. This may be seen from Pope Francis’s 2015 encyclical Laudato Si’, with its focus on climate change. Whatever its merits, it could be criticized for having failed to learn, from the Galileo affair, the lesson that the Church should be wary of interfering in scientific matters.

there’s that exquisite verse, one of the most beautiful in the Bible, the one that says if God cares deeply about sparrows, don’t you think He cares about you? One is so accustomed to dwelling on the second, human, half of the equation, the comforting part, but when you put your hand over that and consider only the first, it’s a little startling: God cares deeply about the sparrows. Not just that, He cares about them individually. “Are not five sparrows sold for two pennies?” Jesus says. “Yet not one of them is forgotten in God’s sight.”

The modern conversation on animal consciousness proceeds, with the rest of the Enlightenment, from the mind of René Descartes, whose take on animals was vividly (and approvingly) paraphrased by the French philosopher Nicolas Malebranche: they “eat without pleasure, cry without pain, grow without knowing it; they desire nothing, fear nothing, know nothing.” Descartes’ term for them was automata

In On the Origin of Species, Charles Darwin made the intriguing claim that among the naturalists he knew it was consistently the case that the better a researcher got to know a certain species, the more each individual animal’s actions appeared attributable to “reason and the less to unlearnt instinct.” The more you knew, the more you suspected that they were rational. That marks an important pivot, that thought, insofar as it took place in the mind of someone devoted to extremely close and meticulous study of living animals, a mind that had trained itself not to sentimentalize.

The sheer number and variety of experiments carried out in the twentieth century—and with, if anything, a renewed intensity in the twenty-first—exceeds summary. Reasoning, language, neurology, the science of emotions—every chamber where “consciousness” is thought to hide has been probed. Birds and chimps and dolphins have been made to look at themselves in mirrors—to observe whether, on the basis of what they see, they groom or preen (a measure, if somewhat arbitrary, of self-awareness). Dolphins have been found to grieve. Primates have learned symbolic or sign languages and then been interrogated with them. Their answers show thinking but have proved stubbornly open to interpretation on the issue of “consciousness,” with critics warning, as always, about the dangers of anthropomorphism, animal-rights bias, etc.

If we put aside the self-awareness standard—and really, how arbitrary and arrogant is that, to take the attribute of consciousness we happen to possess over all creatures and set it atop the hierarchy, proclaiming it the very definition of consciousness (Georg Christoph Lichtenberg wrote something wise in his notebooks, to the effect of: only a man can draw a self-portrait, but only a man wants to)—it becomes possible to say at least the following: the overwhelming tendency of all this scientific work, of its results, has been toward more consciousness. More species having it, and species having more of it than assumed.

The animal kingdom is symphonic with mental activity, and of its millions of wavelengths, we’re born able to understand the minutest sliver. The least we can do is have a proper respect for our ignorance.

The philosopher Thomas Nagel wrote an essay in 1974 titled, “What Is It Like To Be a Bat?”, in which he put forward perhaps the least overweening, most useful definition of “animal consciousness” ever written, one that channels Spinoza’s phrase about “that nature belonging to him wherein he has his being.” Animal consciousness occurs, Nagel wrote, when “there is something that it is to be that organism—something it is like for the organism.” The strangeness of his syntax carries the genuine texture of the problem. We’ll probably never be able to step far enough outside of our species-reality to say much about what is going on with them, beyond saying how like or unlike us they are. Many things are conscious on the earth, and we are one, and our consciousness feels like this; one of the things it causes us to do is doubt the existence of the consciousness of the other millions of species. But it also allows us to imagine a time when we might stop doing that.

ever-more incompetent infants, requiring ever-brighter parents to ensure they survive childhood.

The self-reinforcing nature of the process would explain why intelligence is so strikingly overdeveloped in humans compared even with chimpanzees.

developed first in primates, a newish branch of the mammals, a group that is itself relatively young.

found that babies born to mothers with higher IQs had a better chance of surviving than those born to low-IQ women, which bolsters the idea that looking after human babies is indeed cognitively taxing.

none of this adds up to definitive proof.

Any such feedback loop would be a slow process (at least as reckoned by the humans themselves), most of which would have taken place in the distant past.

It seems there's an association between spending money on one's self and selfish conduct, and it doesn't require actual spending. In this 2009 paper Roy Y.J. Chua and Xi Zou, both professors of management, found that just getting people to think about that kind of spending was sufficient to make their decisions more selfish. The pair showed 87 university students pictures of shoes and watches and had them complete a survey about the products. Then they answered questions about how they would behave as a chief executive in each of three hypothetical business decisions. Half the group had seen pictures of simple, functional shoes and watches. The others had viewed, and then described, top-end luxury goods. Those who saw the luxury versions were significantly more likely to choose the selfish path in the business decisions. They were more inclined to OK the production of a car that would pollute the environment, the release of bug-riddled software, and the marketing of a videogame that would prompt kids to bash each other. That suggests, write Chua and Zou, that "mere exposure to luxury caused people to think more about themselves than others."

“Building a more complex cortex likely involves several things: making more cells, modifying the functions of cortical areas, and changing the connections neurons make with each other

Scientists have become adept at comparing the genomes of different species to identify the DNA sequence changes that underlie those differences. But many human genes are very similar to those of other primates, which suggests that changes in the way genes are regulated — in addition to changes in the genes themselves — is what sets human biology apart.

First, Noonan and his colleagues mapped active regulatory elements in the human genome during the first 12 weeks of cortical development by searching for specific biochemical, or “epigenetic” modifications

same in the developing brains of rhesus monkeys and mice, then compared the three maps to identify those elements that showed greater activity in the developing human brain.

wanted to know the biological impact of those regulatory changes.

They used those data to identify groups of genes that showed coordinated expression in the cerebral cortex.

“While we often think of the human brain as a highly innovative structure, it’s been surprising that so many of these regulatory elements seem to play a role in ancient processes important for building the cortex in all mammals, said first author Steven Reilly

To measure the activity of single neurons, the scientists inserted electrodes thinner than a human hair into the monkey's brain and recorded the neurons' electrical activity. Because the brain is not pain-sensitive, this insertion of electrodes is painless for the animal. By recording from single neurons in an area of the monkey's brain known as area MT, the scientists were able to show that attentional enhancement indeed switches from the first set of neurons to the second set of neurons in a fast and saccade-synchronized manner. Attentional enhancement in the brain is therefore well-timed to maintain spatial attention on relevant stimuli, so that they can be optimally tracked and processed across saccades.

It’s because he’s a reactionary fantasist, whose policies stir the emotions but are stalled in the headwinds of reality

These are not conservative reforms, thought-through, possible to implement, strategically planned. They are the unhinged fantasies of a 71-year-old Fox News viewer imagining he can reconstruct the late 1950s. They cannot actually be implemented, without huge damage.

In Britain, meanwhile, Brexit is in exactly the same place — a reactionary policy that is close to impossible to implement without economic and diplomatic catastrophe

Brexit too was built on Trump-like lies, and a Trump-like fantasy that 50 years of integration with the E.U. could be magically abolished overnight, and that the Britain of the early 1970s could be instantly re-conjured. No actual conservative can possibly believe that such radical, sudden change won’t end in tears.

“The researchers start by simulating what happens when extra links are introduced into a social network. Their network consists of men and women from different races who are randomly distributed. In this model, everyone wants to marry a person of the opposite sex but can only marry someone with whom a connection exists. This leads to a society with a relatively low level of interracial marriage. But if the researchers add random links between people from different ethnic groups, the level of interracial marriage changes dramatically.”

the line to draw, it seems to me, is when a speech is actually shut down or rendered impossible by disruption. A fiery protest that initially prevents an event from starting is one thing; a disruption that prevents the speech taking place at all is another.

Maybe a college could set a time limit for protest — say, ten or fifteen minutes — after which the speaker must be heard, or penalties will be imposed. Heckling — that doesn’t prevent a speech — should also be tolerated to a reasonable extent. There’s a balance here that protects everyone’s free speech

dating apps are changing our society, by becoming the second-most common way straights meet partners, and by expanding the range of people we can meet.

here’s what’s intriguing: Correlated with that is a sustained, and hard-to-explain, rise in interracial marriage.

“It is intriguing that shortly after the introduction of the first dating websites in 1995, like Match.com, the percentage of new marriages created by interracial couples increased rapidly,” say the researchers. “The increase became steeper in the 2000s, when online dating became even more popular. Then, in 2014, the proportion of interracial marriages jumped again.” That was when Tinder took off.

Disruptions of events are, to my mind, integral to the exercise of free speech. Hecklers are part of the contentious and messy world of open debate. To suspend or, after three offenses, expel students for merely disrupting events is not so much to chill the possibility of dissent, but to freeze it altogether.

Even more encouraging, the marriages begun online seem to last longer than others.

I wonder if online dating doesn’t just expand your ability to meet more people of another race, by eliminating geography and the subtle grouping effect of race and class and education. Maybe it lowers some of the social inhibitions against interracial dating.

It’s always seemed to me that racism is deeply ingrained in human nature, and always will be, simply because our primate in-group aversion to members of an out-group expresses itself in racism, unless you actively fight it. You can try every law or custom to mitigate this, but it will only go so far.

the faceless communication social media creates, the linked distances between people, both provokes and mitigates the inherent capacity for monstrosity.

The Gyges effect, the well-noted disinhibition created by communications over the distances of the Internet, in which all speech and image are muted and at arm’s reach, produces an inevitable reaction — the desire for impact at any cost, the desire to reach through the screen, to make somebody feel something, anything. A simple comment can so easily be ignored. Rape threat? Not so much. Or, as Mr. Nunn so succinctly put it on Twitter: “If you can’t threaten to rape a celebrity, what is the point in having them?”

The challenge of our moment is that the face has been at the root of justice and ethics for 2,000 years.

The precondition of any trial, of any attempt to reconcile competing claims, is that the victim and the accused look each other in the face.

For the great French-Jewish philosopher Emmanuel Levinas, the encounter with another’s face was the origin of identity — the reality of the other preceding the formation of the self. The face is the substance, not just the reflection, of the infinity of another person. And from the infinity of the face comes the sense of inevitable obligation, the possibility of discourse, the origin of the ethical impulse.

“Through imitation and mimicry, we are able to feel what other people feel. By being able to feel what other people feel, we are also able to respond compassionately to other people’s emotional states.” The face is the key to the sense of intersubjectivity, linking mimicry and empathy through mirror neurons — the brain mechanism that creates imitation even in nonhuman primates.

Inability to see a face is, in the most direct way, inability to recognize shared humanity with another. In a metastudy of antisocial populations, the inability to sense the emotions on other people’s faces was a key correlation. There is “a consistent, robust link between antisocial behavior and impaired recognition of fearful facial affect. Relative to comparison groups, antisocial populations showed significant impairments in recognizing fearful, sad and surprised expressions.”

Without a face, the self can form only with the rejection of all otherness, with a generalized, all-purpose contempt — a contempt that is so vacuous because it is so vague, and so ferocious because it is so vacuous. A world stripped of faces is a world stripped, not merely of ethics, but of the biological and cultural foundations of ethics.

The spirit of facelessness is coming to define the 21st. Facelessness is not a trend; it is a social phase we are entering that we have not yet figured out how to navigate.

the flight back to the face takes on new urgency. Google recently reported that on Android alone, which has more than a billion active users, people take 93 million selfies a day

Emojis are an explicit attempt to replicate the emotional context that facial expression provides. Intriguingly, emojis express emotion, often negative emotions, but you cannot troll with them.

But all these attempts to provide a digital face run counter to the main current of our era’s essential facelessness. The volume of digital threats appears to be too large for police forces to adequately deal with.

The more established wisdom about trolls, at this point, is to disengage. Obviously, in many cases, actual crimes are being committed, crimes that demand confrontation, by victims and by law enforcement officials, but in everyday digital life engaging with the trolls “is like trying to drown a vampire with your own blood,”

There is a third way, distinct from confrontation or avoidance: compassion

we need a new art of conversation for the new conversations we are having — and the first rule of that art must be to remember that we are talking to human beings: “Never say anything online that you wouldn’t say to somebody’s face.” But also: “Don’t listen to what people wouldn’t say to your face.”

The neurological research demonstrates that empathy, far from being an artificial construct of civilization, is integral to our biology.

It’s what they use to track prey and avoid predation.

The theory of mind is so obvious it’s nearly invisible: it tells us that behavior is the result of the joint operation of pairs of beliefs and desires.

The desires are about the ways we want things to turn out in the future. The beliefs are about the way things are now.

The theory of mind turns what people do into a story with a plot by pairing up the content of beliefs and desires, what they are about.

Psycholinguistics has shown that the theory of mind is necessary for learning language and almost anything else our parents teach us.

Imitating others requires using the theory to figure out what they want us to do and in what order. Without it, you can’t learn much beyond what other higher primates can.

The theory of mind makes us construct stories obsessively, and thus encourages us to see the past as a set of them.

When popular historians seek to know why Hitler declared war on the U.S. (when he didn’t have to), they put the theory of mind to work: What did he believe and what was it that he wanted that made him do such a foolish thing?

he trouble is that the theory of mind is completely wrong about the way the mind, i.e. the brain, actually works. We can’t help but use it to guess what is going on in other people’s minds, and historians rely on it, but the evidence from neuroscience shows that in fact what’s “going on” in anyone’s mind is not decision about what to do in the light of beliefs and desire, but rather a series of neural circuitry firings.

The wrongness of the theory of mind is so profound it makes false all the stories we know and love, in narrative history (and in historical novels).

Neuroscience reveals that the brain is not organized even remotely to work the way the theory of mind says it does. The fact that narrative histories give persistently different answers to questions historians have been asking for centuries should be evidence that storytelling is not where the real answers can be found.

Crucially, they discovered that while different parts of the brain control different things, the neurons’ electrical signals don’t differ in “content”; they are not about different subjects. They are not about anything at all. Each neuron is just in a different part of the mid-brain, doing its job in exactly the same way all other neurons do, sending the same electrochemical oscillations.

There is nothing in our brains to vindicate the theory’s description of how anyone ever makes up his or her mind. And that explains a lot about how bad the theory of mind is at predicting anything much about the future, or explaining anything much about the past.

If we really want historical knowledge we’ll need to use the same tools scientists use — models and theories we can quantify and test. Guessing what was going through Hitler’s mind, and weaving it into a story is no substitute for empirical science.

“Bees manage surprisingly complex behavior with tiny brains,” making the evolution of bee brains an especially interesting subject.

Bees that only go through one generation each year have larger brains, relative to their body size, than bees with multiple generations a year.

A bee with a broad diet can fly into a field and drink the first nectar it finds. But a bee with a specialized diet may have to spot its preferred bloom, with its specific color and fragrance, among a whole field of similar flowers — a task that might require more brain.

Larger brains have also been linked to social behavior in primates and other mammals. But scientists found no connection between brain size and whether a bee lived in hives like honeybees or was a loner like our big-brained aster-eater.

“Highly social species have smaller brains because each individual is more like a cell in the body of the hive,”

Dr. Tibbetts said that even for vertebrates, whether bigger-brained animals are smarter is a topic of wide debate.

It makes sense then, that losing a friend, or being rejected by a group might register to a person as a very dangerous thing. Emotional pain might result if a person discovers that they weren’t invited to a dinner party with friends.

One thing we do know is that people who have a lot of friends have high pain thresholds

Look for cutting edge neuroscience coming out in the next few years that helps us understand how to raise the social pain threshold. We could, very soon, have some practical answers for people with debilitating social anxiety, depression, and loneliness.