On May 4, scientists announced success after a 50-year quest to measure two key consequences of Einstein’s theory of general relativity. The most perfectly round objects ever created by human hand, spinning aboard a spaceship launched in 2004, have detected infinitesimal disturbances in spacetime, the invisible fourth dimension of the universe:

To The Why Files, frame-dragging means that space is no longer flat, or even just warped. It is also twisted. And as a matter of principle, The Why Files likes twisted.

These consequences of predictions made in the early 20th century by history’s archetypal theoretical physicist are yet more proof that Einstein had it right, and are the latest chapters in history’s most compelling scientific detective story; which substantiated the highly theoretical speculation of a brilliant scientist through nuts-and-bolts observations of the universe.

Courtesy Eric Zuelow, University of New England

Is this tyke being “frame-dragged” in accordance with Einstein’s general theory of relativity, or is he just playing in a park in Kenilworth, England?

1905: Relatively special

In 1905, the same year he finished his Ph.D. thesis, Einstein published several amazing insights, including papers on Brownian motion and the photoelectric effect (the latter won Einstein his sole Nobel Prize). One of those papers proposed a theory of “special relativity” that said that the speed of light is fixed and independent of the observer’s motion. The 1887 Michelson-Morley experiment convinced Einstein that there was no ether (the supposed physical background that allowed light to move), and that the laws of physics were the same in reference frames moving with a constant velocity relative to each other.

Common sense says that a ball thrown from a moving car will move faster than one thrown by a person standing still – and still faster for someone in another car driving towards it. Common sense, Einstein proved, does not always apply. The speed of light does not depend on whether the light source is mounted on a Stanley Steamer, a space ship or a water tower. The speed of light is constant. And it doesn’t matter whence you observe it. Light speed is light speed. End of story.

Image: FL0

Using a device like this, Michelson and Morley found that light had the same velocity under different circumstances; a key stimulus to Einstein’s thoughts while working on special relativity.

1916: General relativity

Einstein’s theory of “general” relativity described how gravity affects space and time. Following his habit, Einstein started a thought experiment — a series of “what-if” questions – related to gravity: “If I were falling through space, I would not feel gravity.” Therefore, the laws of physics did not require gravity in every situation. But since the laws of physics must apply everywhere, then gravity must result from something else, which Einstein concluded was the fabric of spacetime.

The classic explanation for spacetime is this: gravity results when the curved fabric of spacetime causes a massive object (a bowling ball or a galaxy) to distort space-time, causing other objects to fall toward the “valley” it has created in spacetime. To us, this looks like gravity, but to Einstein, it’s more a matter of geometry.

1906: Working on the proof

One year after Einstein published special relativity, scientists got some support for the theory, says Richard Staley, an associate professor of the history of science at the University of Wisconsin-Madison. Einstein and others had predicted, for different reasons, that certain fast-moving electrons would gain mass. German physicist Walter Kaufmann did some experiments, and interpreted his results as proof that the mass gain was due to a competing theory rather than relativity, but “the tests were not accurate enough to make a decisive choice between the different theories,” Staley says.

1919: Sun’s gravity bends light

The first confirmation of general relativity appeared after a highly publicized journey by British astronomer Arthur Eddington. During a total solar eclipse, Eddington observed stars that were almost directly behind the sun. As predicted by general relativity, their starlight was bent by the sun’s gravity.

Gravity, counter to intuition, could bend light, and Eddington, no dunce, became an ardent popularizer of relativity.

Although we may look back on Einstein as an oddball with a zany haircut who stuck out his tongue and rode a bike, he was a serious man who thought about politics as well as physics. Living in Germany during World War I, he was an outspoken pacifist who organized scientists against militarism. “Einstein thought we needed to think across national borders and tried to start a book project to include contributions from people from neutral and enemy countries,” Staley notes. “Most of his colleagues said it was a great idea, but would be counterproductive. They refused to participate, so it did not happen.”

Even before his fame got a boost by the 1919 confirmation of relativity, Einstein was willing to “take stances counter to others,” Staley says. “He was cautioned about going public, but when the war was finished, he decided he’d been right. Even though physics does not give you a particular insight into politics, it was clear that nobody had better insights, so he might as well make his views public.”

1974: Neutron stars and gravity waves

By the 1920s and ’30s, relativity was enshrined as a foundation of physics, but the proofs rolled on. In 1974, researchers found that a pair of neutron stars — phenomenally dense objects formed after regular stars collapse — was losing energy. Neutron stars emit extremely regular radio pulses, and the slowing of the pulses was interpreted to mean they were losing energy through the gravitational waves that general relativity predicts. The discovery won the 1993 Nobel Prize for physics.

Detecting gravity waves remains the object of an expensive, long-term scientific quest.

1979: One weighty lens

In 1936, three years after Einstein emigrated to the United States to escape the Nazis, he predicted that immense gravitation would bend light rather like a lens. Contemporary telescopes were unable to find such a “gravitational lens,” but in 1979, astronomers noticed two surprisingly similar images of a distant quasar and concluded that they were looking at a double image of one giant light source, split in two by a cluster of galaxies along the sight path to Earth.

“As usual, Einstein was ahead of the curve,” Harvard historian of science Gerald Holton told The Why Files in 1997. In 2006, a single quasar appeared in five individual images, again due to the gravity of an intervening cluster of galaxies.

Apparently a trillion stars, more or less, will do strange things…

1997: Neutron stars and frame-dragging

Although the 2011 report from Gravity Probe B was the first to identify “frame-dragging” of spacetime due to Earth’s mass, in 1997, scientists reported that rotating black holes and neutron stars were frame-dragging. The study, by Wei Cui at Massachusetts Institute of Technology, found that the gravity of a black hole spinning several thousand of times per second was distorting spacetime into a funnel shape. “It’s a very abstract thing,” Cui told us.

Black holes are extraordinarily dense points in space with a super-intense gravity that even traps light. Their presence can be deduced from a shower of X-rays produced as matter falls into the hole.

Scientists have long accepted that massive objects distort spacetime much as a bowling ball would distort a web of fabric that supports it. But frame-dragging means a rotating mass has some “sticky” quality that drags spacetime, and frame-dragging was more proof that Einstein was right, Cui said. “These are all results of his theory of general relativity, which described gravity.” In other words, gravity becomes a property of spacetime. “You can take all the facts of gravity and explain them with a certain geometry of spacetime.”

1995: The ultimate chill-out

Back in 1925, when “automobile” meant model A, and “president” meant “Silent Cal” Coolidge, Einstein predicted that a strange phase of matter would exist near absolute zero, a frosty -273°C. Expanding upon the calculations of Indian physicist Satyendra Nath Bose, Einstein calculated that atoms would enter a unified quantum-mechanical state near the coldest possible temperature.

The atoms would become a drill sergeant’s dream — identical in mind and body.

What was dubbed the “Bose-Einstein condensate” would also be a new phase of matter. Since only four phases exist in the universe — gas, liquid, solid and plasma — discovering another phase would pump up a resume.
In 1995, Carl Wieman, a professor of physics at the University of Colorado, and colleague Eric Cornell fulfilled Einstein’s prediction by creating this bizarre phase of matter at just 200-billionths of a degree Celsius above absolute zero. As Wieman told us in 1997, “We wanted to see if real atoms could ever match the ideal system that Einstein was considering, and they did match — really quite nicely.”

Quantum mechanics says that atoms can exist in certain energy states, but not in between. A group of atoms occupies numerous energy states, washing out the quantum-mechanical effects, but in a Bose-Einstein condensate, Wieman said, “You have a bunch of atoms in a single quantum state, obeying the laws of quantum mechanics as a whole. Traditionally, to see a quantum state, you had to look inside a single atom. Now we can look at millions of atoms.”

2011: Sweet success smiles on Gravity Probe B

The insights of the former Swiss patent clerk are impossible to exaggerate, but it took a lot of technical sophistication and ingenuity to detect disturbances in spacetime in the vicinity of Earth. That was the goal of Gravity Probe B.

Francis Everitt, a Stanford University physicist who has devoted his career to sailing Gravity Probe B across technological and financial shoals, compares the “dragging” of spacetime to a giant pot of honey. “As the planet rotated its axis and orbited the Sun, the honey around it would warp and swirl, and it’s the same with space and time.”

Save for the effects of gravity and relativity, the high-tech gyroscopes aboard the spaceship should point forever in one direction. Instead, gravity changes their orientation in subtle but measurable ways.

The rotors in those gyroscopes are the most precise spheres ever manufactured, which is astonishing if you consider that they were measured with “micro-inches” rather than microns.

It is not necessary  to offer a practical justification for a proof of relativity – simply explaining the universe is ample. But Gary Shiu, a professor of physics at the University of Wisconsin-Madison, notes that the ultra-precise equipment crafted for the gravity probe helped improve global positioning systems and the gizmos used to map the microwave background radiation that was created shortly after the Big Bang and still pervades the cosmos. “These technologies have already been developed, the spinoff already proven,” Shiu says.

Although some of the previous proofs of general relativity could conceivably be explained with alternate theories, Shiu says, “The frame-dragging detected in Gravity Probe B provides yet another independent test that any alternative to Einstein’s general relativity would have to meet.”

A man apart

A theory must explain the working of some aspect of nature, and it must be tested, generally by trying to disprove its predictions. Does your theory say gravity is an attraction between any two objects? Then, if you can find objects that fail to attract, you need to revise or reject your theory.

After a century of confirmation of Einstein, the obvious remaining question concerns scientific creativity rather than physics: What was Einstein’s secret? “He was very persistent, was the prototypical scientist,” says Shiu, who helped organize an upcoming conference on Cosmology since Einstein. “When he wanted to solve a problem, he could take 10 or 20 years. We cannot figure out the answer in a few months or years, we need to do whatever it takes to solve the problem.”

Kip Thorne, a California Institute of Technology physicist, told us in 1997 that he attributed Einstein’s deep insight to his “conviction that the universe loves simplicity and beauty… His willingness to be guided by this conviction, even if it meant destroying the foundations of Newtonian physics, led him, with a clarity of thought that others could not match, to his new description of space and time. … All new laws that have been successful in describing the real universe have turned out to obey Einstein’s principle of relativity.”

Indeed, Thorne called relativity a kind of super-law that “must be obeyed by all laws of physics, no matter whether they are laws governing electricity and magnetism, or atoms and molecules, or steam engines and sports cars.”

Gerald Holton, a physicist and historian of science at Harvard University, pointed to several characteristics that helped Einstein ^{1 2} excel:

Beyond a unique ability to peer inside the universe, Holton says Einstein also wrote about his philosophy and technique. “This man allowed himself to be more public and frank, and in particular about his scientific method, which is very much the method still used by other physicists.”

Yet for all his brilliance, Einstein failed to find the holy Grail of physics –a “grand unified theory” to explain all four physical forces. Electromagnetism and the strong and weak nuclear forces are explained by a single theory called the “standard model,” but to this day, gravitation stands stubbornly apart.

Summing up? Einstein

Einstein’s revolutionary theories grew from his philosophy of nature and insistence that physical laws must be true on Earth, space ships and stars, combined with a phenomenal intuition for nature and enough self-confidence to rewrite Newton’s laws of gravitation and motion. Einstein interpreted experiments from the 1880s, which suggested that the speed of light was independent of the observer’s motion, as meaning that the speed of light is constant throughout the universe. He then proposed that mass would affect light and spacetime, which is the backdrop for all events, atomic, human, cosmic and comic.

Still, everybody makes mistakes. Einstein denied the existence of black holes and loathed the role of chance in quantum theory, saying “God does not play dice with the universe.” He also cooked up a “cosmological constant” because his theories implied that the universe was changing size, which he considered too weird to be true.

When astronomer Edwin Hubble proved that the universe was expanding, Einstein called the cosmo constant “the greatest blunder of his life.” And yet recent discoveries indicating that the universe is, for unknown reasons, expanding ever faster could mean that his “greatest blunder” was not that far off…

Although Newtonian physics still describes what we see every day, more than a century after the young patent clerk brutally shouldered Newton aside, there’s no question Einstein grasped the big picture. And that returns us to this simple question: “How did he do the things he did?”

“Einstein was typically working between several different theoretical approaches,” says Staley, the science historian. “He was looking for places in which the best laws we currently have fail or don’t provide clear guidance, and then was trying to use those critical gaps to provide new insight into connections between different areas. People often think he thought outside the box. I think he thought across several boxes, and saw ways to link theory that others did not recognize. Although others were also looking at the limits of theory and trying to unify different areas, he did it better.”

For decades, one name has dominated discussion of the ancient New World: Clovis. Tools representing the characteristic Clovis technology, first found in Clovis, New Mexico, in 1929, have long been considered the product of the first inhabitants of the Americas. With a tool style that’s been found across much of North America, Clovis was the best-selling brand in “the first Americans” competition.

Clovis technology is apparently a home-grown phenomenon, as it’s never been found in Northeast Asia, the source of migrants into the New World.

The oldest solid date for Clovis people is 13,100 years ago, says Michael Waters, an archeologist at Texas A&M University. Now, in an article in Science on March 25, Waters and colleagues argue that tools have been found near Austin, Texas, that date to 15,500 years ago.

The researchers found 15,528 artifacts at a site called Buttermilk Creek. Most of their finds were flakes busted off while making stone tools, but the site also yielded 56 stone choppers, points and scrapers.

Using a technique that calculated when an object was last in direct sunlight, “We took the most conservative route to estimate the age,” says Waters, who directs the Center for the Study of the First Americans at A&M. The stone tools and flakes were probably made by a band of hunter-gatherers who paused at the creekside site.

Looking for a date

Because no organic remains were available for carbon-dating, the scientists relied for dating on optically stimulated luminescence, or OSL. “OSL has been around for a long time, has been employed in geology for 30-plus years” for dating windblown sand and silt, says Waters. “It’s been compared to radiocarbon dates, toe-to-toe, and in all cases, OSL ages have been determined to be comparable.”

The OSL dating, which essentially figures how long something has been buried, took place at the University of Illinois, in Chicago, under the direction of Steven Forman.

The find at Buttermilk Creek is the latest — and one of the better documented — archeological sites to break the Clovis barrier. Others pre-Clovis finds have been made in Oregon, Wisconsin, Pennsylvania and even Chile.

The news got WhyFilers wondering:

How convincing?

To get the skinny on the Texas discovery, we phoned Steve Shackley, a professor of anthropology at the University of California at Berkeley. “Proof does not exist in science,” he told us, “but Mike [Waters] has made good, defensible arguments.”

Much of the discussion about the Buttermilk Creek site concerns the vertical position — the stratigraphy — of stone artifacts, and the Waters team went to great lengths to show that older material was under younger stuff, as expected in an undisturbed site. Undetected dislocations can confuse archeologists, who tend to think deeper is older and shallower is younger.

Buttermilk Creek actually offers a three-fer: Clovis artifacts are sandwiched above those now identified as pre-Clovis, but below artifacts are in a more modern style. “This site has all these time periods, superimposed, in the correct order,” says Shackley. Because Waters is “one of the foremost” experts in analyzing the geology of archeological sites, “I think it’s going to be difficult to defeat his stratigraphic work. He’s been very careful about it.”

Douglas Bamforth, an archeologist at the University of Colorado, says the Waters team has avoided three errors that often destabilize ancient archeological claims:

“They have absolutely dated the site, they absolutely have artifacts, and the article talks in great detail about how intact the sediment was, they have really addressed whether the artifacts are in place,” says Bamforth. “They have refitted the [stone] flakes to the tools; I am totally convinced they have an intact site” and solid dates.

But that does not prove, to Bamforth, that the artifacts are pre-Clovis — they may be early Clovis. “The deep levels at the site are certainly older than the oldest carbon-14 date on Clovis-style projectile points, which Waters very emphatically argues is the beginning of the Clovis period. But the first problem with seeing the deep levels as different from Clovis is that there seems to be exactly nothing in those levels that differs from Clovis [as the site does not contain arrow- or spear-points that would prove or disprove the case]. … So I do not see why the site is not just early Clovis.”

Not so fast!

Aware that the latest find may be seen as final vindication for the “Clovis was not first” viewpoint, we phoned Thomas Dillehay, professor of anthropology at Vanderbilt University and the University of Southern Chile, who fought for decades to have Chile’s Monte Verde site recognized as pre-Clovis. Now that Monte Verde is finally accepted as one of the best-confirmed pre-Clovis sites, we figured the experience would make Dillehay receptive to the new find.

We were wrong. “I have a mixed opinion,” Dillehay told us, proceeding to list some shortcomings in the study. “It would be most convincing if there was standard radiocarbon dating, and even better if those dates were taken from features like hearths and food stains. OSL dating has become more reliable, but it’s still not as reliable as carbon-14, although the sequences do line up very nicely with sediment dating.”

Dillehay has questions about the three-layer sandwich of pre-Clovis, Clovis and post-Clovis material. “I’m not saying the materials are mixed. Geologists, to identify the strata, applied these excellent, meticulous sediment and particle analyses, but there was no clear visible stratigraphy to distinguish Clovis from pre-Clovis, and again this does not meet standard archeological criteria.”

Dillehay also points to the lack of “diagnostic, complete projectile points in either the Clovis and pre-Clovis material. In a discipline that has placed incredibly heavy emphasis on formal projectile points as the primary criteria for acceptance of a site, along with C-14 [radioactive carbon] dating, and geologic stratigraphy, I find this sort of acceptance, which seems to be uncritical, to be a major shift in the discipline.”

Still, Dillehay says “the interdisciplinary work is first rate, and I admire the multidisciplinary approach. But had there been C-14 dating and diagnostic projectile points, all this extraneous analysis would probably not be needed.”

It certainly would be nice to find arrow- or spear-points, says Waters, but “You can’t dictate what you will find. You have to roll with the punches.” Further excavation may or may not reveal a “smoking gun projectile point,” Waters adds. “We don’t know what kind of weaponry they used. In Siberia and Alaska, people were using a lot of bone, ivory and antler weaponry, and it might be that early folks in North America were using this as well.”

But due to heat and humidity, such organic material would not be preserved in the Texas site, he says.

Migration routes

The timing of human occupation of North America bears heavily on their migration route from Northeast Asia, which is accepted, for geographic and genetic reasons, as the source of the first Americans. The melting of the last ice age during the Clovis period, starting roughly 11,000 years ago, producing an ice-free corridor through Northwest Canada that would have allowed transit into the North American interior.

But the region was clogged with glaciers a few thousand years earlier, meaning that any early immigrants would have moved along the coast, either on foot, or via short hops in boats.

The possibility of coastal movement got a boost in a study¹ published March 4, which reported the discovery of stone tools dating from 11,400 to 12,200 years ago on the Channel Islands west of Los Angeles.

According to study leader Jon Erlandson, an archeologist at the University of Oregon, the ancient residents of these offshore islands made delicate stone tools to hunt in the ocean. “The points we are finding are extraordinary, the workmanship amazing. They are ultra thin, serrated and have incredible barbs on them. It’s a very sophisticated chipped-stone technology.”

The stone artifacts are quite different from the fluted points left throughout North America by Clovis and the later Folsom peoples, who hunted big game on land, said Erlandson. “This is among the earliest evidence of seafaring and maritime adaptations in the Americas, and another extension of the diversity of Paleoindian economies.”

The find is yet another reason to doubt that Clovis was first, says Shackley. “When you get dates to 11,000 or 12,000 years ago, out on islands, that makes it tough for the Clovis-firsters, who reject maritime entry. On the Channel Islands, they had get out there by boat,” and if they were already using boats, that means they could also have boated down the West Coast, he adds. “A lot of people accept that now.”

But even if people did move south along the coast rather than inland, Dillehay says they probably needed a long time to reach Chile. “There are hundreds if not thousands of rivers that descend the western slope of the mountain chain from Alaska to Tierra del Fuego, and every river, whether major or secondary, is a temptation to head upriver,” slowing the overall southward movement.

Photo: University of Oregon Northern Great Basin Field School

In Paisley caves in south-central Oregon, researchers uncovered pre-Clovis artifacts and the oldest human DNA discovered in the Americas. Radiocarbon dates show that people lived in the caves between 12,000 and 14,340 years ago.

And if Monte Verde was occupied by 14,500 years ago, this logic suggests that people reached North America much earlier than even the 15,500 pre-Clovis date in Texas.

Should we trademark the “pre-pre-Clovis” brand?

At any rate, the increasing number of solid pre-Clovis finds answers a riddle: How did Clovis artifacts appear in so many places at roughly the same time? According to the Waters report, “These data are evidence that by 15.5 ka [thousand years ago], human populations occupied the continental United States… . The sites of Cactus Hill, Virginia, and Miles Point, Maryland, hint that these [pre-Clovis] technologies may have been present a few millennia earlier. This early occupation of North America provides ample time for people to settle into the environments of North America, colonize South America by at least about 14.1 to 14.6 ka (Monte Verde, Chile), develop the Clovis tool kit, and create a base population through which Clovis technology could spread.” ²

When science gets ossified

Although we’ve covered the Texas discovery as a bit of gee-whiz archeology, it’s more accurate to say that the discipline proceeds by stacking study atop study, says Sissel Schroeder, a professor of anthropology at the University of Wisconsin-Madison and expert on ancient peoples of the Americas. Although most of the signs left by people who lived in North America will never be found, if they even still exist, “We work with the best information we have. The very small samples of data can make some of our interpretations less robust. Archeology is a cumulative science, so future finds can potentially add confirmatory evidence, or can disconfirm earlier conclusions; you just have to be open to recognizing that your interpretations could change.”

But scientists, like other people, can get stuck, she adds. “It seems easy for certain interpretive frameworks to become quite entrenched, and repeated over and over again. Into the 1920s, it was hugely debated that there were even people in the Americas” at the end of the last ice age. “There were a number of very provocative finds that led scholars to suggest that people had been here at the end of the Pleistocene [about 12,000 years ago], but wasn’t until the find at Folsom, New Mexico [in 1926] that scholarly acceptance began to develop.”

The Folsom find, soon followed by the discovery of those distinctive fluted points near Clovis, New Mexico, sparked “a transformative intellectual step for archeologists,” says Schroeder. “This was a radical shift in thinking.”

“You build a reputation based on a particular perspective,” says Bamforth, “and it’s hard to see evidence that is in opposition; we all believe we are really good at what we do.” Those who gain fame for overturning the conventional wisdom can wind up in the opposite corner, defending their own views long after contradictory evidence arises.

Some early claims for pre-Clovis sites were based on faulty excavation or inaccurate dating, which left a tradition of doubt, Bamforth says. For example, erroneous radiocarbon dates arose after dig sites were contaminated with groundwater. And European-style artifacts unearthed in the Hudson River valley, once interpreted as evidence for ancient European immigration, actually came from ship’s ballast that was dumped into the river, Bamforth told us.

Once archeologists got used to refuting claims, that skeptical attitude itself became entrenched, says Bamforth. “Because people were making such poor claims, very powerful people in the field clamped down on any claims for antiquity, and often the rejected claims turned out to be correct. People at the Smithsonian famously had nothing to do with Folsom until finally the evidence carried the day. There’s a famous photo showing a Folsom spearpoint between the ribs of an extinct bison. That’s proof you can’t argue with.”

Clovis-first is dead, at long last!

After 40 years of assault, Clovis-first seems dead at last. The Texas find “anchors the fact that people were here in the 14,000 or 15,000 year range, there is no longer an argument with that,” says Bamforth.

As the technology of archeology improves, Waters expects some of the most interesting finds to emerge from South America. “We have this North American bias. I’ve heard a lot about early sites in South America of the same age [as the Texas site] or older that nobody hears about. If you think about the immensity of South America, there is no way Clovis was first. There are going to be some amazing finds in the next 10 years, given the South American evidence, the work with genetics and DNA. The story of the first Americans is going to stay exciting.”

– David J. Tenenbaum

Admit it: You love your dog, your cat, even your white rat.

And so you’re planning to lavish a platter of filet mignon on your doggy-love… a plank of sushi-grade tuna on kitty numero-uno, and some aged cheese on your rodent.

But do our dogs, cats and rats love us back?

Sure, parrots are endlessly uttering “I love you” on You Tube, and some bereaved dogs seem to grieve for their dead owners.

And yes, some animals “love” to spend time together.

But that doesn’t answer our nagging question: Can animals really love?

Or are we projecting our own feelings of affiliation, closeness, and passion on beasts that don’t have the mental machinery to love?

Almost like being in love?

More than half a century ago, Harry Harlow, a research psychologist at the University of Wisconsin-Madison, performed experiments that forever changed our view of human and animal emotions. At a time when academic psychologists explored learning and behavior by studying rats, when low-grade learning in a “Skinner Box” was considered high-grade science, when hospitals limited contact between mothers and their newborns, Harlow focused on maternal touch and the emotional life of monkeys.

Harlow removed infant macaques from their mothers, then raised them with a mother surrogate made of cloth or wire. In some experiments, both surrogates were present.

Monkeys with the cloth mommas grew up fairly normal, but infants raised with only the wire monkey became fearful and desperate. Their behavior was so bizarre that they seemed psychologically broken by the lack of a loving — or at least a cuddly-if-inanimate — mother.

Infants that had access to both types of bogus mother still relied on the cloth mother for reassurance even if the wire monkey held their bottle.

Harlow interpreted the lifelong devastation of maternal deprivation as proof that infant monkeys need love, and that became early, influential evidence that animals can love, says his biographer¹, Deborah Blum, a professor of journalism at UW-Madison. “Up until that point, people were arguing that these animals were not capable of having emotions. Harlow led the way in demonstrating that these animals loved, had affection, mattered to each other. He used the word ‘love’ very deliberately,” Blum adds, even though his fellow psychologists were highly skeptical, not to say scornful, of that notion.

It didn’t take popular psychology, aided by Harlow’s humorous, down-to-earth approach, long to realize that the then-current “scientific” preference for antiseptic infancy would deprive young people of necessary contact, Blum notes. The instinctive desire to hug an infant, it turned out, gained support from the most rigorous scientific experiments.

My romance

Scientists who say that primates need maternal love are no longer mocked by their peers. But what is love? Charles Snowdon, a UW-Madison professor of psychology who has explored primate behavior for 35 years, offers this definition: “a preference for one other individual that is more or less exclusive and long-lasting, and that transcends other relationships.”

Animal love is evident in behavior when animals are separated from their mates, Snowdon says. “In species that form lifelong attachments, if a mate dies or disappears, often the remaining mate does not form a new pair bond at all.”

Snowdon says the cotton-top tamarin he studied form strong attachments. “If they were separated, they would begin long calls, at a rate much higher than they would give when together. These plaintive calls would last for the entire 30 minutes of separation. When they were reunited, they cuddled and often had sex.”

As if that did not sound human enough, Snowdon next floored us by discussing “romantic love.” Decades ago, psychologists worked overtime to avoid being accused of anthropomorphism — projecting human qualities onto animals. Now it’s kosher to talk about an emotion once restricted to the primates that buy heart-shaped tchotchkes each February.

Snowdon says romantic love supports the bond in a mated pair, and it’s not just about primates. “Albatrosses and geese appear to form lifelong pair bonds, and robins, blue jays and cardinals might form relationships that last for at least one breeding season; these are strong attachments.”

Snowdon adds that experiments with titi monkeys belie the notion that the sole goal of animal attachment is to nurture the next generation. “If you separate the mother, father and infant from each other, and give them a choice, mothers and fathers choose to be with each other and ignore the baby. It is clear that pairs want to be with each other, to the exclusion of the baby.”

Like someone in love

While Harlow relied on observing behavior, today scientists study the brain chemicals that mold the Valentine’s heart. One key subject is the hormone oxytocin, which plays a critical role in social bonding and love, both animal and human.

Oxytocin, originally identified for its role in helping mothers bond with newborns, also rises in men and women after sex and other close, emotional encounters. In the big picture, oxytocin enables attachment in humans and other animals, Snowdon says. “You don’t find oxytocin elevated in animals unless they form an adult attachment with one other individual.”

The brain responds to dopamine, a feel-good chemical that is released during many pleasurable activities, including drug-taking. Dopamine also plays a role in animal love – and “marital” fidelity. Mated prairie voles have a higher level of a specific dopamine receptor in a brain region called the nucleus accumbens, says Karen Bales, an associate professor of psychology at the University of California at Davis. “When these are turned on, that prevents them from forming a second pair bond.”

When owners interact with their dogs, both sides have surges in oxytocin, says Bales, who studies primates at the California National Primate Research Center. “That puts a check in the ‘dogs can love’ box.”

Love fur sale

Because dogs are the most glaring example of an animal that seems to love people, we phoned Patricia McConnell, an author³, and animal behaviorist at UW-Madison. She gave us two key reasons why dogs can love: “Their physiology for creating social attachment is so similar to ours, and they behave in ways that, if any human did it, we’d label it love, attachment.”

Like many other mammals, dogs respond to oxytocin: “It’s a huge part of social attachment, and physiologically it’s almost an exact replica of oxytocin in humans,” McConnell says.

Dogs appear to grieve, McConnell adds. “They get distressed when someone they are attached to is gone. There are lots of credible examples of dogs risking their lives to save a human. We are so different from dogs in so many ways, but in some ways, we are more similar to them than to other animals. What other species is obsessed with the fate of a ball?”

If dogs love us, what about each other? “Absolutely, yes,” says McConnell. “I have seen dogs behave as if they instantly fell in love: they are animated, their eyes were shining, they were extra playful. But I’ve also seen dogs that clearly took an instant dislike to each other.”

Dogs, like people, are picky, so it’s not always possible to replace a deceased member of a tight pair, McConnell says. “When people get another dog, they’re often surprised that the resident dog is not thrilled. We see the exact same thing in people: Personalities can clash or meld. When someone you know dies, it will not help if a stranger walks in off the street.”

You don’t know what love is

Still, animals can’t say what they are feeling, and so we must rely on measurements and observations. Interpreting animal behavior can be difficult, says Marga Vicedo, a historian of science at the University of Toronto who has written about Harlow’s experiments.⁴

Vicedo recalls members of an animal-behavior seminar who would “discuss, week after week, how you would interpret it when they look left — or right? You are seeing a behavior, and from the behavior, you have to hypothesize about the emotions, but there is not a perfect correlation between animal and human emotions.”

Interpreting the emotional basis of behavior is difficult enough with people, Vicedo observes. “We may laugh at a meeting, but inside we are depressed. You can only observe behavior, and have to figure out its relationship to emotion and feeling.”

Stephen Marc Breedlove, who studies hormones and behavior at Michigan State University, reiterated that problem. “Whether you think your dog loves you or your boyfriend loves you, there is the same problem: you see the behavior and from that, you infer these feelings. With a partner, you can ask, but since people do lie, that is not completely reliable.”

My one and only love?

Our improved understanding of what’s going on inside the brain provides more ways to analyze animal emotion, Breedlove says. “In certain species, there is neural circuitry that helps monogamous pairs stay attached to one another. We know the same systems can be present in humans — and although we don’t know they serve the exact same function, there is some danger in insisting we are absolutely unique in every way. Natural selection produces a continuum of traits, we can’t have something arise from nothing.”

Indeed, evolution is a great re-user of its own inventions, as Breedlove stresses. “What is the evidence that makes you think love arose absolutely de novo [without precedent] in our species? And then, when did it arise, in Mesopotamia?”

The notion that animals can love is part of a scientific sea change. Once upon a time — even after Harlow — identifying emotions in animals was considered anthropomorphism, a fatal fallacy that could ruin a career in psychology or animal behavior.

Now, we have seen a “change in the zeitgeist [the spirit of the time],” says Breedlove. “People are open to the possibility that animals have emotions, and I think that is a step forward, a sign of maturity of the field. Anthropomorphism is definitely a risky business, but people are less worried that they will be written off as cranks just because they say something that could be interpreted as anthropomorphism.”

As we’ve seen, many scientists are even willing to discuss parallels in animal and human love. Heresy!

Almost like being in love

In burying the old “animals are just beasts that cannot have feelings” mentality, nobody has been more influential than primatologist Frans de Waal of Emory University. When we asked whether animals can love, he responded, “Mammals are almost made for attachment, because of their maternal care obligations, the female is attached to her offspring and vice versa. There is a whole brain circuitry attached to that.”

Still, the subjective aspect is hard to know, de Waal admits. Even though studies find attachment, affiliation — and arguably love — in rodents, dogs and primates, “what they experience is not something we can know, but given that they show all the signs of attachment, they spend time together, are distressed if they are separated, and show what looks like happy behavior when they are reunited,” it’s unclear why we should deny the obvious explanation: these animals have emotions.

“If a chimp’s offspring dies,” de Waal says, “it usually keeps carrying it around until it falls apart, so even though the offspring is dead, the attachment stays intact; these are all signs of strong attachments.”

Comes love

We asked de Waal if we could summarize his view as, ‘It looks like love, but we’ll never know?’ but he said we had it backwards. “My assumption is the other way around, that if animals that are closely related to us, as monkeys and chimps certainly are, and do similar things under similar circumstances, we have to assume the psychology behind it is similar. It would be very inefficient for nature to produce the same behavior in different ways in a monkey and a human, it would have to create a different mechanism, a different psychology and neurology. From the Darwinist standpoint it does not make sense that monkeys would arrive at the same place via a different way.”

de Wall said his view is that “If chimps show strong attachment, we have got to assume the psychology is similar, and that would include the experience. That is not an assumption that is easily verified, but I think it is better than the opposite, that it looks the same, but is probably different.”

Given the current hostility to government, you could be forgiven for thinking that “bureaucrat” is a euphemism for “bottom feeder” or “control freak.”

But does bureaucracy contain the keys to making a large state? Did bureaucracy’s characteristic division of administrative labor and power allow ancient states to rule areas that were too large to walk across in a day?

Yes, says anthropologist Charles Spencer of the American Museum of Natural History in New York. In an article in the Proceedings of the National Academy of Sciences this week, Spencer looked at states that arose thousands of years ago, in isolation from any other state.

He found that, so far as the archeological record could say, the rise of bureaucracy and the territorial expansion were more or less simultaneous. In contrast to another more traditional view of state development, the expansion did not occur long after bureaucracy appeared.

The six states under study were in Mexico, Peru, Egypt, Iraq, China and Pakistan’s Indus Valley.

“In all six cases this model seems to work, which suggests that this process of territorial expansion is perhaps how a state bureaucracy evolves in the first place,” says Spencer.

He adds that the tight link between bureaucracy and expansion “may tell us something fundamental about the nature of states and bureaucracy.”

All photos copyright Charles S. Spencer, AMNH, used with permission

The main plaza of Monte Albán, in the Oaxaca Valley. Building J (foreground), features some 40 stone slabs with inscriptions showing the city’s conquests.

Three stages of development

Chicken or egg?

When historians and social scientists pondered the origin of states, many figured that the growth of the bureaucracy was a precondition for an imperialist expansion of territory. But Spencer believes that territorial expansion and the growth of bureaucracy are united in a positive feedback loop. “There is much evidence that the pre-bureaucratic system seems to be spatially more limited. Once you start getting involved in managing territory beyond that limit, you have to have a delegation of authority to secondary and tertiary centers; this seems to be a requirement for maintaining one of these larger political-economic territories.”

Spencer says chiefs were apparently loath to dispatch powerful lieutenants to administer provinces, for fear they would go rogue, but the bureaucratic structure made it safer to send out tax collectors or generals with a limited array of powers. “To move toward a larger polity, it’s necessary to assign powers and roles,” he says. But this strategy requires a fundamentally different kind of administration, one based on bureaucratic principles.

Roots of an idea

The blond clay in “Crema” pottery came from a source near Monte Albán. The timing and distribution of crema ware shows when and where Monte Albán traded with other settlements in the Oaxaca Valley.

Spencer says he began thinking about the state development in the 1970s, while doing research at the ancient city of Monte Albán, located in south-central Mexico’s Oaxaca Valley. He says Monte Albán began to acquire a bureaucratic form of government around 300 BC, and the city flourished for roughly 800 years.

The specialization that characterizes bureaucracy is evident in the “diverse array” of buildings and temples at Monte Albán itself, Spencer wrote.

The Oaxaca Valley is a large, three-lobed valley, and as Spencer explored how Monte Albán gathered more territory, he found the expansion toward the north “happened much earlier than most people thought, and was in fact contemporaneous with the appearance of state institutions around 300 BC.”

That did not jibe with the theory that the bureaucracy arose first, long before the state expanded its territory to distant regions, but rather indicated that the bureaucracy and the territory expanded at the same time. “I started to think about how territorial expansion, rather than being a consequence of state formation, might be the mechanism through which the state arose, and the extra resources generated by expansion would help finance the administrative transformation itself.”

The El Palenque palace, near San Martín Tilcajete, in the Oaxaca Valley, dates to 300-100 B.C. Although this is the earliest palace yet excavated in the Valley, a similar but larger palace probably existed at Monte Albán during this period.

States may expand violently or peacefully, Spencer says. “There are ways to impose your will on another territory that may not involve killing. You may set up an economic relationship that is far more favorable to you than to them, with the understanding that if they do not play along, they will get squashed.”

On April 15th – America’s tax day – “bureaucracy” may conjure the Internal Revenue Service, but bureaucracies can be more beneficent or more sinister than that. “Government can do very good things, but this research suggests that the state, and by extension the bureaucracy, is inherently expansionistic, you might even say inherently predatory, and that is a cautionary note we need to keep in mind,” Spencer says. When a state initiates unprovoked warfare, “we should remember that this is perhaps the oldest doctrine of all in the story of states.”

–David J. Tenenbaum