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It was late afternoon in the winter scrub desert within Namibia’s Etosha National Park when I spotted a family of elephants on the southern edge of the clearing. I was scanning the horizon from the observation tower where my colleagues and I conduct our research at Mushara water hole. Wind had deterred elephant families from visiting the water hole earlier—it interferes with their efforts to keep tabs on one another vocally—but with the air now still, our first customers of the day had finally appeared.

Judging from how many trunks were stretched high, sampling the air, the group was itching to break cover and run for the water. The young males were particularly anxious to get going. Not only were they thirsty, but they had a lot of sparring to catch up on. As winter wears on, the environment dries out, and elephants have to venture farther from water to find enough to eat. Several days may pass before they can return to the water hole for a drink and a reunion.

I could see why this group was holding back, however. Another elephant family was amassing in the southeastern forest and heading our way, and the adult females were wary. They stood with their feet firmly planted, ears held straight out, as they sniffed what little remained of the prevailing wind for any potential danger. Not only would exiting the security of the forest expose the family to predators, but an encounter with a higher-ranking elephant family could result in an aggressive interaction. For the youngsters in the group, however, more families meant more opportunities to play. So after thoroughly assessing the clearing, the matriarch gave the word with a rumble and an ear flap, and the family began its approach to the water.

Late afternoon is my favorite time of day during our field season in the austral winter—the air cools fast as the sun sinks low in the sky, painting the elephants a radiant pink. My colleagues and I stand in the observation tower with a celebratory drink in hand, our binoculars trained on the horizon, hoping for a sunset visit like this one from one of our beloved resident families. During these daily visits, I always learn a new lesson about elephants—particularly when they play.

I have witnessed the important role of play in calf development and family politics by watching members of my favorite elephant groups frolic at this water hole at sunset. These often chaotic observations inspired me to want to understand more about how animals play and what advantages this behavior might confer, not just to elephants but to all social creatures, including humans. It turns out that play, like other forms of interaction, has rules of engagement. And it is essential for developing the physical and cognitive faculties that animals need to survive and reproduce.

Rules and Regulations

People tend to think of play as an activity one engages in at one’s leisure, outside of learning important skills needed to succeed later in life, such as hunting, mating, and evading predators. But although playing is fun for all involved—and fun for those who are watching—play behaviors evolved as ritualized forms of survival skills needed later in life, providing the opportunity to perfect those skills.

Engaging in play allows animals to experiment with new behaviors in a protected environment without dangerous consequences. The unwritten code of conduct surrounding play lets them explore many possible outcomes.

Animals learn the rules of engagement for play at a very young age. Among dogs, the bow is a universal invitation to engage in silliness that triggers the same bowing down and splaying of the front legs in the receiver of the signal—inevitably followed by chasing and pretend biting. Chimpanzees and gorillas motivate others to romp by showing their upper and lower teeth in what primatologists refer to as a play face, which is comparable to human laughter.

When a young male elephant wants to play with another male of similar age, he holds his trunk up and presents it to the other as an invitation. Most often his next move would be to place his trunk over the other’s head, which in adults signals dominance but in calves is guaranteed to precipitate a spirited sparring match. These encounters run the gamut from gentle shoving to intense headbutting and pushing back and forth with trunks entwining and tusks clacking. The fun continues for seconds to minutes for youngsters; for older teens and young adults, it can go on much longer. The sparring matches provide bulls with the opportunity to test their fighting ability so that they might successfully compete for a female when they reach sexual maturity and enter the hormonal state of musth around the age of 25.

When a young male elephant is feeling particularly adventurous, he may venture far away from Mom’s protection to invite a distant relative to spar. If his foray takes him too far away or if a spar turns unexpectedly rough, the brave calf will lose his nerve and often will run quickly back to Mom’s side with ears flapping and trunk yo-yoing as he retreats.

Occasionally an older sister will oversee a play bout between youngsters. These ever watchful siblings form part of an extended caretaking network that facilitates play, but its members also will intervene if a calf crosses an invisible bloodline and gets deflected with a trunk slap by an overly protective, high-ranking mother.

Forms of Play

Scholars of animal behavior recognize three main categories of play. The first is social play, which is any kind of antic that involves others. The second is locomotive play—including running, walking, jumping and pouncing—which facilitates lifelong motor skills. In prey species, locomotive play helps to perfect predator-avoidance tactics such as the springbok’s “pronking” high into the air while running as a herd and landing in unpredictable spots. In elephants, it hones predator-avoidance skills, as well as strategies for escaping an aggressive suitor or a competitor looking to inflict a mortal wound. Conversely, young predators such as lion cubs use locomotive play to sharpen their hunting ability. Chasing and tripping littermates and then giving them a good chew on the spine or throat are rehearsals of the skills needed to catch prey animals and dispatch them by severing their spinal cord or choking them.

Many species, including our own, engage in the mock-fighting variety of locomotive play, which allows them to test their strength in a safe environment where everyone understands the rules. A playful spar in elephants is just like an arm wrestle between human peers. When play becomes more elaborate and determined, it turns from an arm wrestle into something akin to martial arts, allowing both participants to practice skills and develop innovative solutions that could help them avoid mortal combat later in life. Play fighting also provides opportunities to test boundaries, gauge who can be trusted and learn important body language.

The third main category of play is object play, which incorporates objects from the environment into the cavorting. For an elephant, this object might take the form of a stick or branch that the elephant explores, carries or throws with its trunk. In captivity, elephants enjoy playing with balls or hauling inner tubes around for fun. Alternatively, the object could be another animal, such as a zebra or giraffe, that offers an irresistible opportunity for a chase. In one case, a four-year-old male calf named Leo taught his baby brother, Liam, just how fun such a chase can be, leaving Liam scrambling to keep up with Leo’s charge as a giraffe made a quick escape.

Two other forms of play have been documented only in great apes, including humans. One of these, game playing, combines social, locomotive and object play. Sports such as soccer, field hockey, lacrosse and polo are examples of traditional games that became formalized as sports with specific sets of rules (among nonhuman great apes, only captive individuals raised in human contexts play formal games). The other variety of play that appears to be unique to great apes is make-believe. For example, a wild chimpanzee may carry around a small log, pretending it is an infant. A human child might play with an invisible toy or set up an invisible barrier that they want adults to acknowledge.

Not Just Fun and Games

Play provides an environment for experimenting with risk. When a lion cub deliberately gives up some control over its body, it puts itself at a disadvantage, allowing others to succeed in pouncing on it. Marc Bekoff of the University of Colorado Boulder and his colleagues have proposed that play increases the versatility of movements used to recover from a loss of balance and enhances the ability of the player to cope with unexpected stressful situations. The goal is not to win but to improve skills, sometimes by self-handicapping.

Once a cub has been tackled by its littermates, roles might reverse such that a littermate handicaps itself, allowing the other cub to tackle it in return. Self-handicapping is risky and requires trust, but it is a great way to develop strength and agility. It is also an important exercise in building cooperation. In the Sawtooth wolf pack raised by Jim and Jamie Dutcher in the Sawtooth Mountains in Idaho, the dominant wolf would slow down to allow a close companion that happened to be a subordinate to catch up and tackle him. In elephants, on a number of occasions I have seen older male calves crouch down to allow a much younger calf to spar with them. This is akin to an older brother handicapping himself during an arm wrestle by not using all of his strength to let his little brother win.

Being silly is another important aspect of play, one that gets us outside our comfort zone and forces us to test new strategies. Silliness in our movements, behavior and even language helps us think much more broadly and creatively. Problem-solving derived from the silliness of play has been demonstrated in many species and even in robots. When mechanical engineer Hod Lipson of Columbia University gave his artificial-intelligence robots a chance to play—by dancing around in random movements—they outperformed other robots when challenged with the unexpected. The positioning information garnered from moving around randomly led one robot to come up with creative solutions for maintaining its balance after losing a limb.

Likewise, when sea lions play in the surf, they often project themselves high into the air midway down the face of monster waves, like those that roll into Santa Cruz. These are just the kinds of behaviors needed to avoid an attack by a great white shark—their primary predator apart from killer whales and humans.

Play also builds trust. Thomas Bugnyar of the University of Vienna in Austria and his colleagues found that ravens pretend to cache highly valued food items and then watch how other ravens respond, apparently to determine whom they can trust. Learning how to differentiate competitors from likely reliable collaborators early on has obvious advantages, whether one wants to gain allies or build a coalition within a group—or repair broken relationships.

Families Reunited

“Incoming from the southeast!” I called out from the Mushara tower as my elephant field team narrowed in on what looked like a dusty line of pinkish-gray boulders amassing on the edge of the clearing one afternoon during our 2018 field season. The search for identifying features began. A missing tusk, a notch in the bottom of the left ear, or a V-shaped cut in the top of the right ear would give the family away. Whoever identified the elephant family first would get an extra sundown drink.

That day the incoming family turned out to be the Actors. It was our first sighting of the group that season, and we were excited to see a new addition to the family: high-ranking Susan, identified by her daggerlike left tusk, had a new male calf, Liam. And low-ranking Wynona, who was missing her left tusk, had her two-year-old calf Lucy in tow. We had been following the contentious dynamic between these two mothers very closely over the years, particularly during the 2012 season when each had a calf—Leo and Liza, respectively.

Susan had relentlessly tormented Wynona all the way up to the end of her pregnancy, aggressively charging her whenever she got close to the water to drink. The tension was so high that when Wynona broke away from the family to give birth, surrounded by her daughter Erin and their calves, I worried for her baby’s life if a reunion were to take place. Sure enough, there was no fanfare and no reunion that we witnessed to present her new baby to the rest of the family. I assumed then that Wynona’s days as a member of the Actor family were numbered.

As predicted, Wynona did separate from the larger family and became the matriarch of her own core family. It went on like that for four years until the arrival of Wynona’s newest baby, Lucy, in 2016 yet again changed the dynamic of the larger extended family group. Play appeared to be an important contributing factor in reuniting the family.

Lucy’s older sister, Liza, had been a shy baby who stuck to her mom and her very close relatives. Wynona timed her movements to avoid too much overlap with the larger family group when they went to Mushara water hole to drink. They tended to be one day behind or ahead of the Actor family, usually behind. On the rare occasion that they did overlap just at the end of the extended family visit, Liza did not stray to interact with the larger family. And who would blame her? Susan was right there with a quick jab with her dagger tusk or a trunk slap, whichever was more convenient, making it clear that the low-ranking babies had no place on the playground with royalty. There was hardly a chance for calves of Wynona’s small but growing family to get to know members of the extended family.

Lucy changed all that. From the start, she was quite the extrovert. Maybe being born into a very small family made her all the more curious and excited by the opportunity to engage with the extended family on the infrequent occasion of their overlapping. And she was not deterred by the admonishments of high-ranking moms within the extended family, much to the seeming annoyance of the ever watchful Susan.

Now the two-year-old Lucy knew just how to run through adults’ legs and out of trunk’s reach, navigating potential minefields and dodging her mom’s attempts to rein her in. She behaved more like Susan’s calf, Leo, who was her older sister Liza’s contemporary. When we scored Leo’s distance from his mom at the water hole, he always had a much higher score than Liza. We had assumed that was attributable mainly to his sex and the male elephant’s early experiments with independence. But the arrival of Lucy showed us that the story was not that simple.

Lucy spent a lot of time a great distance away from her mom and played with calves of mothers of all ranks. When it came time to leave the water hole and go in separate directions, as dictated by the prevailing family politics, Lucy made that impossible. She was so busy playing with other calves that there was no extracting her, leaving Wynona no choice but to modify her behavior.

Instead of continuing on her premeditated departure route, in the opposite direction from the Actor family, Wynona, her eldest daughter Erin and their calves turned around and followed the rest of the family so that Wynona did not risk losing her new calf. There was no guarantee that the other mothers would protect Lucy, much less allow her to suckle, as that would mean fewer precious nutrients for their own calves. But by 2018 Wynona was fully reintegrated into the Actor family, whether she wanted to be or not.

Every time I see this dynamic unfold, it makes me smile. How often is it the case in our own families that grudges of older generations are put aside because of the bonds forged by the next generation through play?

Play should be on our daily agenda. Smiling and laughing are contagious behaviors that facilitate bonding, are curative and, most important, do not have to take up much time. The next time you feel like you are too busy to play a frivolous game at work or you don’t want to face that family reunion, make the time and muster the will. You might be surprised at the outcome, whether it be a better idea for a pitch meeting or the dissolution of a long-standing barrier between you and a contentious relative thanks to a good giggle.

Our highly adaptable and innovative nature is rooted in play. I am grateful to my favorite elephant, Wynona, and her daughter Lucy for reminding me that there is always something new we can learn from it—and that we are never too old to internalize those lessons. A good romp can pay off in ways I hadn’t anticipated. It forges new bonds, reunites divided families, improves coping skills and overall health, and facilitates cooperation and innovation. Given all these benefits, how could we afford not to play?

Trees that communicate, care for one another and foster cooperative communities have captured the popular imagination, most notably in Suzanne Simard’s much-praised book Finding the Mother Tree, soon to be a movie, and in other works like James Cameron’s Avatar, Peter Wohlleben’s The Hidden Life of Trees and Richard Powers’ Pulitzer Prize–winning novel The Overstory.

But many scientists like myself believe these depictions misrepresent ecosystems and harm the cause of conservation.

Do trees really talk? Sure. Plants emit hormones and defense signals. Other plants detect these signals and alter their physiology accordingly. But not all the talk is kind; plants also produce allelochemicals, which poison their neighbors.

Simard and others showed that carbon compounds made by one tree can end up in neighboring trees via the underground network of mycorrhizae, fungi that live on plant roots and exchange water and nutrients they gather from the soil for sugars plants make. They suggest that donor trees purposely and sacrificially send nourishment to others to help them grow and ensure the health of the community.

How would this work? Like other ecological interactions, cooperation must evolve by natural selection, in which traits increase in frequency because individuals who have them produce more offspring and pass on the traits.   

Perhaps the simplest explanation is that the fungus shuttles carbon around to protect its own interests, cultivating multiple hosts to ensure its future supply of food.

Altruism can arise if a recipient is likely to reciprocate, ultimately benefiting the donor. Reciprocity among trees is possible, but many interactions are likely asymmetric, such as between mature trees and tiny seedlings.

Altruistic behavior can also evolve if it benefits relatives, who pass on the donor’s genes. Emerging evidence shows nutrient redistribution via mycorrhizal networks benefits kin more than unrelated plants. The mechanisms by which plants might recognize and respond to their relatives have yet to be fully worked out.

Unfortunately, the explanation most favored by popularizers, that trees send out resources to strengthen the community, is least likely. This would require natural selection to be countered by group selection—where groups that cooperate win out over groups that do not. When these forces conflict, natural selection almost always wins, because individuals are so much more numerous than groups and turn over much more rapidly.

Interestingly, when mycorrhizae transfer resources from a native grass to an invasive weed, this is interpreted as evidence of parasitism, not cooperation.

Overemphasizing cooperation is misleading. The forest floor is a forum of fierce competition. A mature maple tree produces millions of seeds, and on average only one will grow to reach the canopy. The rest will die, with or without help from mom.

Amid this struggle, trees can sometimes facilitate each other’s growth. But this does not mean that a forest functions like one organism. An ecosystem comprises an ever-changing diversity of organisms having an ever-changing variety of interactions, positive and negative.

After the last glaciation, different tree species migrated north at different rates and by different routes. The beech-maple forest, or the oak-hickory forest, did not move as a unit. In fact, trees currently live in combinations that may have no analog in the past or future.

Anthropomorphism is taboo in science because it deceives us more often than it helps. Trees are not people and forests are not human families or even republics. Suggesting that they are can only lead us to imaginary conclusions.

In interviews, Simard has said that she purposely uses anthropomorphism and culturally weighted words like “mother”—even though the trees in question are male as well as female—so that people can relate to trees better, because “if we can relate to it, then we’re going to care about it more.”

Do trees need to have human values and emotions for us to let them live? The science supporting conservation is compelling enough. New discoveries about the underground world are thrilling enough. The public deserves to hear the true story, without the confusion of personification and stretched metaphor.

These distractions keep us from confronting reality: facilitation may be real, but so is the Darwinian struggle for existence. We are moral creatures in an amoral world. Nature does not share our values, and mercifully, we may choose not to emulate all of nature’s ways.

Between treating plants as objects or as humans, I suggest a third way: let’s seek to understand plants on their own terms. Plants are fundamentally unlike us: mute, rooted and inscrutable. We need to meet the challenge of cultivating respect for organisms that are different from us—in their separate and complex bodies, in their sophisticated interactions, in their unfathomable lives.

This is an opinion and analysis article; the views expressed by the author or authors are not necessarily those of Scientific American.

The hottest spots in the search for alien life are a few frigid moons in the outer solar system, each known to harbor a liquid-water ocean beneath its icy exterior. There is Saturn’s moon Titan, which hides a thick layer of briny water beneath a frozen surface dotted with lakes of liquid hydrocarbon. Titan’s sister Saturnian moon Enceladus has revealed its subsurface sea with geyserlike plumes venting from cracks near its south pole. Plumes also emanate from a moon that is one planet closer to the sun: Jupiter’s Europa, which boasts a watery deep so vast that, by volume, it dwarfs all of Earth’s oceans combined. Each of these aquatic extraterrestrial locales might be the site of a “second genesis,” an emergence of life of the same sort that occurred on Earth billions of years ago.

Astrobiologists are now pursuing multiple interplanetary missions to learn whether any of these ocean-bearing moons actually possess more than mere water—namely, habitability, or the nuanced geochemical conditions required for life to arise and flourish. NASA’s instrument-packed Europa Clipper spacecraft, for example, could begin its orbital investigations of Jupiter’s enigmatic moon by 2030. And another mission, a nuclear-fueled flying drone called Dragonfly, is scheduled to touch down on Titan as early as 2036. As impressive as these missions are, however, they are only preludes to future efforts that could more directly hunt for alien life itself. But in those strange sunless places so unlike our own world, how will astrobiologists know life when they see it?

More often than not, the “biosignatures” scientists look for in such searches are subtle chemical tracers of life’s past or current presence on a planet rather than anything so obvious as a fossilized form protruding from a rock or a little green humanoid waving hello. The instruments on NASA’s Perseverance Mars rover, for instance, can detect organic compounds and salts in and around its landing site: Jezero Crater, a dry lakebed that may contain evidence of past life. And in the fall of 2020 some astronomers telescopically studying Venus may have teased out the presence of phosphine gas there, a possible by-product of putative microbes floating in temperate regions of the planet’s atmosphere.

The trouble is that many simple biosignatures can be produced both by living things and through abiotic geochemical processes. Much of the phosphine on Earth comes from microbes, but Venus’s phosphine, if it exists at all, could potentially be linked to erupting volcanoes rather than some alien ecosystem in its clouds. Such ambiguities can lead to false positives, cases in which scientists think they see life where none exists. At the same time, if organisms possess radically different biochemistry and physiology from that of terrestrial creatures, scientists could instead encounter false negatives, cases in which they do not recognize life despite having evidence for its presence. Especially when contemplating prospects for life on distinctly alien worlds such as the ocean moons of the outer solar system, researchers must carefully navigate between these two interlinked hazards—the Scylla and Charybdis of astrobiology.

Now, however, a study recently published in the Bulletin of Mathematical Biology offers a novel approach. By shifting attention from specific chemical tracers—such as phosphine—to the broader question of how biological processes reorganize materials across entire ecosystems, the paper’s authors say, astrobiologists could illuminate new types of less ambiguous biosignatures. These clues would be suitable for discovering life in its myriad possible forms—even if that life employed profoundly unearthly biochemistry.

Sizing Up a Sea Change

The study relies on stoichiometry, which measures the elemental ratios that appear in the chemistry of cells and ecosystems. The researchers began with the observation that within groups of cells, chemical ratios vary with striking regularity. The classic example of this regularity is the Redfield ratio—a 16:1 average proportion of nitrogen to phosphorus displayed with remarkable consistency by phytoplankton blooms throughout Earth’s oceans. Other kinds of cells, such as certain types of bacteria, also exhibit their own characteristically consistent ratios. If the regularity of chemical ratios within cells is a universal property of biological systems, here or anywhere else in the cosmos, then careful stoichiometry could be the key to eventually discovering life on an alien world.

Importantly, however, these elemental proportions change in accordance with cell size, allowing for an additional check on any curiously consistent but possibly abiotic chemical ratios on another world. In bacteria, for instance, as cells get larger, concentrations of protein molecules decrease, whereas concentrations of nucleic acids increase. In contrast to groups of nonliving particles, biological particles will display “ratios that systematically change with cell size,” explains Santa Fe Institute researcher Chris Kempes, who led the new study, which expanded on prior work by co-author Simon Levin, also at the Santa Fe Institute. The trick is to devise a general theory of how, exactly, the various sizes of cells affect elemental abundances—which is precisely what Kempes, Levin and their colleagues did.

They focused on the fact that, at least for Earth life, as cell sizes increase in a fluid, their abundance decreases in a mathematically patterned way—specifically, as a power law, the rate of which can be expressed by a negative exponent. This suggests that, if astrobiologists know the size distribution of cells (or cell-like particles) in a fluid, they can predict the elemental abundances within those materials. In essence, this could be a potent recipe for determining whether a group of unknown particles, say within a sample of Europan seawater, harbors anything alive. “If we observe a system where we have particles with systematic relationships between elemental ratios and size, and the surrounding fluid does not contain these ratios,” Kempes explains, “we have a strong signal that the ecosystem may contain life.”

Testing the Waters

The study’s emphasis on such “ecological biosignatures” is the latest in a slow-simmering, decades-long quest to link life not only to the fundamental limitations of physics and chemistry but also to the specific environments in which it appears. It would, after all, be somewhat naive to assume organisms on the sunbathed surface of a warm, rocky planet would have the very same chemical biosignatures as those dwelling within the lightless depths of an oceanic moon. “There has been a constant evolution in ideas, in approaches, and that’s really important,” explains Jim Green, NASA’s chief scientist, who was not involved in the new study. “Now we are entering an era where we can go after what we know about how life has evolved and apply that as a general principle.”

So what does it take to bring this more holistic approach to biosignatures to our studies of worlds such as Europa, Titan and Enceladus? At the moment, Green explains, it will take more than the space agency’s Europa Clipper orbiter—perhaps a follow-up mission to the surface would suffice. “Through Clipper, we want to take much more detailed measurements, fly through the plume, study the evolution of Europa over a period of time and capture high-resolution images,” he says. “This would take us to the next step, which would be to get down to the ground. That’s where the next generation of ideas and instruments need to come in.”

Looking for the ecological biosignatures described by Kempes and his colleagues would require instrumentation that measures the size distribution and chemical composition of cells within their native fluid. On Earth, the technique that scientists use to sort cells by size is called flow cytometry, and it is used frequently in marine environments. But performing cytometry in an alien moon’s subsurface ocean would be far more challenging than merely sending instrumentation there: Because of the paucity of available energy in those sunlight-starved abysses, scientists expect any life there to be single-celled, extremely small and relatively sparse. To capture such organisms in the first place would require careful filtering and then a refined flow cytometer that would measure particles of this size range.

Our current flow cytometers are not up to that task, explains Sarah Maurer, a biochemist and astrobiologist at Central Connecticut University, who was not involved with the study. Many kinds of cells simply do not get picked up, and “there are cell types that require extensive preparation or they won’t go through a cytometer,” she says. To work in space, instruments to filter and sort cells would need both refinement on Earth and miniaturization for spaceflight.

Progress is already being made on both fronts, according to study co-author Heather Graham of the NASA-funded Laboratory for Agnostic Biosignatures and the agency’s Goddard Space Flight Center. The next steps, she says, will be to deploy new tools at marginally habitable field sites around the globe that play host to some of Earth’s most extreme and impoverished ecosystems. Once astrobiologists begin routinely discerning the distinctive chemical ratios associated with living ecosystems in our own planet’s quiescent waters, they can fine-tune the specifications for spaceflight-capable devices—and, just maybe, at last reveal a second genesis, written within the mathematics of a subsurface ocean’s chemistry.

In the year since a Minneapolis police officer kneeled on George Floyd’s neck for more than nine minutes and stopped the man’s heart, a record number of protesters have taken to the streets around the world to demand change. Earlier this year a jury took the all too extraordinary step of convicting the officer of murder. But the incessant killing of Black people and “the devaluation of Black lives in all domains of American life,” as sociologist Aldon Morris writes, continue to power the Black Lives Matter movement, which was launched in 2013 after the acquittal of Trayvon Martin’s killer in Florida.

It is an unequivocal scientific fact that race is a social construct, not a biological one. The implicit prejudices and biases we carry against those unlike us are real, but society instills them in our subconscious mind, and they are therefore malleable.

Discrimination oppresses and disenfranchises people everywhere. Misattributing blame for racist systems and practices to its victims constitutes a kind of institutional-level gaslighting that enforces white supremacy. In everyday interactions, those with privilege and power subtly insult those in the “out-group” through microaggressions that reinforce their power structure and inflict psychological harm. Even the way people talk about certain scientific fields keeps women and minority groups excluded from academia and related professions. And despite institutional efforts to increase diversity and inclusion, science is plagued by discrimination and loss of minority talent.

Public health expert Camara Phyllis Jones explains why such institutional racism, not race, has made people of color more than twice as likely to die from COVID-19. And irrespective of the global pandemic, Black children and other minorities are disproportionately born into poverty and thus incur more health risks throughout their lives. Black mothers suffer higher rates of maternal mortality, and doctors and algorithms often overlook or discount medical symptoms experienced by Black people.

In the wake of Floyd’s murder, civil rights expert Alexis J. Hoag recounted to Scientific American the violent, racist history that brought U.S. society to a breaking point—one where Black people are about three times more likely than white people to be killed by law enforcement. In September 2020 the editors of Scientific American called for sweeping reforms of U.S. law enforcement, from demilitarizing police forces to hiring more social workers and mental health professionals to respond to nonviolent incidents.

People of color are more likely to suffer the consequences of a degraded and plundered environment as well: Those with power benefit from exploiting the natural world, but it’s the poorest among us who bear the impacts, including toxic pollution. Asian, Hispanic and Black people experience the highest rates of asthma in the nation, which are strongly linked to dirty inner-city air.

In her influential book Why Are All the Black Kids Sitting Together in the Cafeteria?, psychologist Beverly Daniel Tatum analogized racism this way: as a moving walkway at the airport that will carry you along unless you walk, vigorously, in the other direction. As Morris writes, lasting change will depend on how well each of us can disrupt the regimes of racial inequality. We must all turn around and conscientiously walk toward a more just world.