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October 6, 2016
A gorilla-suit experiment reveals our closest animal relatives may possess “theory of mind”
By Catherine Caruso
A chimpanzee at the Kumamoto Sanctuary prepares to watch experimental scenarios that will test her understanding of false belief, a hallmark of theory of mind.
KUMAMOTO SANCTUARY, KYOTO UNIVERSITY, JAPAN
A chimpanzee, a scientist with a stick and a researcher in a King Kong suit may sound like the setup for a bad joke, but it is in fact the basis of a recent study that provides the first evidence that great apes—that is, bonobos, chimpanzees and orangutans—possess an understanding of false belief, a hallmark of “theory of mind.” This ability to understand that others have mental states and perspectives different than our own has long been considered unique to humans.
In the study, published Thursday in Science, a team of scientists recorded the eye movements of three great ape species while the animals watched videos of a man searching for a hidden object that had been moved without his knowledge, and found that they looked more frequently at the location where the man expected the object to be (a belief the apes knew was false), even though the object was no longer there. The findings suggest the apes were able to intuit what the human was thinking.
Theory of mind is central to our social functioning as humans, but scientists have long wondered whether it is, in fact, a uniquely human trait. There is evidence that apes can understand other’s mental states when they match up with reality, but apes have consistently failed tests of false belief—the idea that someone else may act according to a belief that is untrue. Fumihiro Kano of Kyoto University’s Kumamoto Sanctuary and a co-leader of the study calls this ability a “litmus test” for theory of mind. Traditional false-belief tests for apes have involved complicated tasks such as moving around cups to reveal hidden food. This is why Kano and study co-leader Christopher Krupenye of the Max Planck Institute for Evolutionary Anthropology adapted a simpler false-belief test designed for human infants that utilizes an eye-tracking method called anticipatory looking, or gazing at where you expect a person to look for an object.
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During the study, bonobos, chimpanzees and orangutans were “invited” one at a time to sit in a room and drink juice while watching a sequence of scenarios on a video monitor. An infrared camera below the monitor recorded where on the screen the animals were looking as they watched the scenes unfold. To capture the apes’ attention, the researchers made each experimental scenario into a high stakes television drama starring a mysterious apelike character (a researcher in a gorilla suit), whom they dubbed King Kong.
Like humans, great apes are “pretty obsessed with social information—when there's a conflict within their group everybody stops and pays attention,” Krupenye says. “This is just their version of the Jersey Shore that we made so they would be really engaged and curious about what was going to happen.”
In one scenario the King Kong figure pretended to attack a researcher, then hid in one of two hay bales, moving to the other bale while the researcher watched. Then the researcher left for awhile before returning with a stick to look for King Kong, who had left the scene while the researcher was away. In another scenario the costumed figure moved to the other hay bale after the researcher left and then departed entirely. The researchers also set up the same two scenarios in a slightly different setting—instead of hiding himself, King Kong hid a stolen rock under one of two boxes before removing it completely.
Apes from all three species consistently passed the test; even though the animals knew King Kong or the rock was gone, when the researcher returned to search for it, they consistently looked at the hay bale or box where the person had last seen the object and presumably still thought it was hidden. These results are particularly surprising because they challenge the large body of previous work that suggests great apes are not capable of comprehending beliefs that are untrue. “People have thought for awhile that false-belief understanding is unique to humans,” Krupenye says, “and so this suggests that apes do have at least a basic, implicit understanding of false belief, which has been seen as a signature of theory of mind.”
Their findings drew both praise and debate in the field. In an article about the study also published today in Science , Frans de Waal, a primatologist who studies social intelligence at Emory University and was not involved with the work, wrote the study design “is a genuine breakthrough, not only because it avoids an undue reliance on language skills required to understand narrative and questions in theory of mind testing in children, but also because it highlights the mental continuity between great apes and humans.”
Tecumseh Fitch, an evolutionary biologist and cognitive scientist at the University of Vienna, also not part of the research, sees this as the “final nail in the coffin of the long-standing idea that humans are the only species with ‘theory of mind.’”
Others are skeptical of that interpretation, however. Carla Krachun at the University of Saskatchewan and Robert Lurz at Brooklyn College, who both study theory of mind in primates, are excited that the researchers were able to indirectly measure apes’ mental processes using eye tracking, which “opens up all sorts of possibilities for studying theory of mind in apes,” they wrote in an e-mail. Krachun and Lurz do not think the study definitively demonstrates false-belief understanding, however. “The issue is that subjects could use a simple behavior rule—‘agents search for things where they last saw them’—to pass the tests without understanding anything about the agent’s false beliefs,” they explained.
Kato and Krupenye acknowledge the difficulty of interpreting their findings but still see them as an important step forward in our understanding of great ape cognition. “There are other kinds of false beliefs that I think we need to test in order to be sure that apes are relying on this more sophisticated skill,” Krupenye says. “But the big thing here is that the apes clearly have a more sophisticated understanding of others than we previously thought, and that means they can predict others' behavior even in contexts when the actor is misguided, and that's something that humans do all the time.”
Advanced Artificial Intelligence (AI) systems, specifically large language models (LLMs), have the capability to generate not just misinformation, but also deceptive explanations that can justify and propagate false information and erode trust in the truth. We examined the impact of deceptive AI generated explanations on individuals' beliefs in a pre-registered online experiment with 23,840 observations from 1,192 participants. We found that in addition to being more persuasive than accurate and honest explanations, AI-generated deceptive explanations can significantly amplify belief in false news headlines and undermine true ones as compared to AI systems that simply classify the headline incorrectly as being true/false. Moreover, our results show that personal factors such as cognitive reflection and trust in AI do not necessarily protect individuals from these effects caused by deceptive AI generated explanations. Instead, our results show that the logical validity of AI generated deceptive explanations, that is whether the explanation has a causal effect on the truthfulness of the AI's classification, plays a critical role in countering their persuasiveness - with logically invalid explanations being deemed less credible. This underscores the importance of teaching logical reasoning and critical thinking skills to identify logically invalid arguments, fostering greater resilience against advanced AI-driven misinformation.
July 30, 2024
Nico Roper/ Quanta Magazine
Metaphysics is the branch of philosophy that deals in the deep scaffolding of the world: the nature of space, time, causation and existence, the foundations of reality itself. It’s generally considered untestable, since metaphysical assumptions underlie all our efforts to conduct tests and interpret results. Those assumptions usually go unspoken.
Most of the time, that’s fine. Intuitions we have about the way the world works rarely conflict with our everyday experience. At speeds far slower than the speed of light or at scales far larger than the quantum one, we can, for instance, assume that objects have definite features independent of our measurements, that we all share a universal space and time, that a fact for one of us is a fact for all. As long as our philosophy works, it lurks undetected in the background, leading us to mistakenly believe that science is something separable from metaphysics.
But at the uncharted edges of experience — at high speeds and tiny scales — those intuitions cease to serve us, making it impossible for us to do science without confronting our philosophical assumptions head-on. Suddenly we find ourselves in a place where science and philosophy can no longer be neatly distinguished. A place, according to the physicist Eric Cavalcanti , called “experimental metaphysics.”
Eric Cavalcanti of Griffith University in Brisbane, Australia, calls himself an “experimental metaphysicist.”
Luke Marsden for Quanta Magazine
Cavalcanti is carrying the torch of a tradition that stretches back through a long line of rebellious thinkers who have resisted the usual dividing lines between physics and philosophy. In experimental metaphysics, the tools of science can be used to test our philosophical worldviews, which in turn can be used to better understand science. Cavalcanti, a 46-year-old native of Brazil who is a professor at Griffith University in Brisbane, Australia, and his colleagues have published the strongest result attained in experimental metaphysics yet, a theorem that places strict and surprising constraints on the nature of reality. They’re now designing clever, if controversial, experiments to test our assumptions not only about physics, but about the mind.
While we might expect the injection of philosophy into science to result in something less scientific, in fact, says Cavalcanti, the opposite is true. “In some sense, the knowledge that we obtain through experimental metaphysics is more secure and more scientific,” he said, because it vets not only our scientific hypotheses but the premises that usually lie hidden beneath.
THE DIVIDING LINE between science and philosophy has never been clear. Often, it’s drawn along testability. Any science that deserves its name is said to be vulnerable to tests that can falsify it, while philosophy aims for pristine truths that hover somewhere beyond the grubby reach of experiment. So long as that distinction is in play, physicists believe they can get on with the messy business of “real science” and leave the philosophers in their armchairs, stroking their chins.
As it turns out, though, the testability distinction doesn’t hold. Philosophers have long known that it’s impossible to prove a hypothesis. (No matter how many white swans you see, the next one could be black.) That’s why Karl Popper famously said that a statement is only scientific if it’s falsifiable — if we can’t prove it, we can at least try to disprove it. In 1906, though, the French physicist Pierre Duhem showed that falsifying a single hypothesis is impossible. Every piece of science is bound up in a tangled mesh of assumptions, he argued. These assumptions are about everything from underlying physical laws to the workings of specific measurement devices. If the result of your experiment appears to disprove your hypothesis, you can always account for the data by tweaking one of your assumptions while leaving your hypothesis intact.
Take, for instance, the geometry of space-time. Immanuel Kant, the 18th-century philosopher, declared that the properties of space and time are not empirical questions. He thought not only that the geometry of space was necessarily Euclidean, meaning that a triangle’s interior angles add up to 180 degrees, but that this fact had to be “the basis of any future metaphysics.” It wasn’t empirically testable, according to Kant, because it provided the very framework within which we understand how our tests work in the first place.
And yet in 1919, when astronomers measured the path of distant starlight skirting the gravitational influence of the sun, they found that the geometry of space wasn’t Euclidean after all — it was warped by gravity, as Albert Einstein had recently predicted.
Or did they? Henri Poincaré, the French polymath, offered up an intriguing thought experiment. Imagine that the universe is a giant disk that conforms to Euclidean geometry, but whose physical laws include the following: The disk is hottest in the middle and coldest at the edge, with the temperature falling in proportion to the square of the distance from the center. Moreover, this universe features a refractive index — a measurement of how light rays bend — that is inversely proportional to the temperature. In such a universe, rulers and yardsticks would never be straight (solid objects would expand and shrink with the temperature gradient) while the refractive index would make light rays appear to travel in curves rather than lines. As a result, any attempt to measure the geometry of the space — say, by adding up the angles of a triangle — would lead one to believe that the space was non-Euclidean.
Any test of geometry requires you to assume certain laws of physics, while any test of those laws of physics requires you to assume the geometry. Sure, the disk world’s physical laws seem ad hoc, but so are Euclid’s axioms. “Poincaré, in my opinion, is right,” Einstein said in a 1921 lecture. He added, “Only the sum of geometry and physical laws is subject to experimental verification.” As the American logician Willard V. O. Quine put it, “The unit of empirical significance” — the thing that’s actually testable — “is the whole of science.” The simplest observation (that the sky is blue, say, or the particle is there) forces us to question everything we know about the workings of the universe.
But actually, it’s worse than that. The unit of empirical significance is a combination of science and philosophy. The thinker who saw this most clearly was the 20th-century Swiss mathematician Ferdinand Gonseth. For Gonseth, science and metaphysics are always in conversation with one another, with metaphysics providing the foundations on which science operates, science providing evidence that forces metaphysics to revise those foundations, and the two together adapting and changing like a living, breathing organism. As he said in a symposium he attended in Einstein’s honor, “Science and philosophy form a single whole.”
With the two tied together in a Gordian knot, we might be tempted to throw up our hands, since we can’t put scientific statements to the test without dragging metaphysical statements along with them. But there’s a flipside to the story: It means that metaphysics is testable. That’s why Cavalcanti, who works at the very edges of quantum knowledge, doesn’t refer to himself as a physicist, or as a philosopher, but as an “experimental metaphysicist.”
I MET WITH CAVALCANTI on a video call. With his dark hair pulled back into a bun, he had a brooding look about him, his careful, serious demeanor offset only by a 15-week-old puppy squirming in his lap. He told me how, as an undergraduate in Brazil in the late 1990s, he worked on experimental biophysics — “very wet stuff,” as he describes it, “getting hearts out of rabbits and putting them under [superconducting] magnetometers,” that sort of thing. Though he soon moved on to drier territory (“working in particle accelerators, studying atomic collisions”), the work was still far from the metaphysical questions already lingering in his mind. “I had been told that the interesting questions in foundations of quantum mechanics had all been resolved by [Niels] Bohr in his debates with Einstein,” he said. So he measured another cross section, churned out another paper, and did it all again the next day.
Cavalcanti clears his mind in a forest near campus.
Luke Marsden
He ended up working for Brazil’s National Nuclear Energy Commission, and it was there that he read books by the physicists Roger Penrose and David Deutsch, each offering up a radically different metaphysical story to account for the facts of quantum mechanics. Should we give up the philosophical assumption that there’s only one universe, as Deutsch suggested? Or, as Penrose preferred, perhaps quantum theory ceases to apply at large scales, when gravity gets in on the action. “Here were these brilliant physicists who not only are directly discussing questions about foundations but profoundly disagreeing with each other,” Cavalcanti said. Penrose, he added, “even went beyond physics into what’s traditionally metaphysics, asking questions about consciousness.”
Inspired, Cavalcanti decided to pursue a doctorate in quantum foundations and found a place for himself at the University of Queensland in Australia. His dissertation began, “To understand the source of the conflicts of quantum foundations, it is essential to know where and how our classical models and intuitions start to fail to describe a quantum world. This is the subject of experimental metaphysics.” A professor put the thesis down and declared, “This isn’t physics.”
But Cavalcanti was prepared to make the case that the line between physics and philosophy had already been blurred beyond repair. In the 1960s, the Northern Irish physicist John Stewart Bell had also encountered a culture of physics that had no patience for philosophy. The days of Einstein and Bohr arguing over the nature of reality — and engaging deeply with philosophy in the process — were long over. Postwar practicality reigned, and physicists were eager to get on with the business of physics, as if the Gordian knot had been cut, as if it were possible to ignore metaphysics and still manage to do science at all. But Bell, doing his heretical work in his spare time, discovered a new possibility: While it’s true that you can’t test a single hypothesis in isolation, you can take multiple metaphysical assumptions and see if they stand or fall together.
For Bell, those assumptions are typically understood to be locality (the belief that things can’t influence each other instantaneously across space) and realism (that there’s some way things simply are, independent of their being measured). His theorem, published in 1964, proved what’s known as Bell’s inequality : For any theory operating under the assumptions of locality and realism, there’s an upper limit on how correlated certain events can be. Quantum mechanics, however, predicted correlations that busted through that upper limit.
As written, Bell’s theorem wasn’t testable, but in 1969 the physicist and philosopher Abner Shimony saw that it could be rewritten in a form suitable for the lab. Along with John Clauser, Michael Horne and Richard Holt, Shimony transformed Bell’s inequality into the CHSH inequality (named for its authors’ initials), and in 1972, in a basement in Berkeley, California, Clauser and his collaborator Stuart Freedman put it to the test by measuring correlations between pairs of photons.
The results showed that the world bore out the predictions of quantum mechanics, showing correlations that remained far stronger than Bell’s inequality allowed. This meant that locality and realism can’t both be features of reality — though which of the two we ought to abandon, the experiments couldn’t say. “To my mind, the most fascinating thing about theorems of Bell’s type is that they provide a rare opportunity for an enterprise which can properly be called ‘experimental metaphysics,’” Shimony wrote in 1980 in the statement that’s widely believed to have coined the term.
As it happens, though, the term goes back further, to a most unlikely character. Michele Besso, Einstein’s best friend and sounding board, was the only person Einstein credited with helping him come up with the theory of relativity. But Besso helped less with the physics than with the philosophy. Einstein had always been a realist, believing in a reality behind the scenes, independent of our observations, but Besso introduced him to the philosophical writings of Ernst Mach, who argued that a theory should only refer to measurable quantities. Mach, by way of Besso, encouraged Einstein to give up his metaphysical notions of absolute space, time and motion. The result was the special theory of relativity.
Upon its publication in 1905, physicists weren’t sure whether the theory was physics or philosophy. All of its equations had already been written down by others; it was only the metaphysics behind them that was new. But that metaphysics was enough to lead to new science, as special relativity gave way to general relativity, a new theory of gravity, complete with new, testable predictions. Besso later befriended Gonseth; in Switzerland, the two took long walks together, where Gonseth argued that physics could never be placed on firm foundations, since experiments can always overturn the most bedrock assumptions on which it is built. In a letter, which Gonseth published in a 1948 issue of the journal Dialectica , Besso suggested that Gonseth refer to his work as “experimental metaphysics.”
Experimental metaphysics gained something of an official headquarters in the 1970s with the founding of the Association Ferdinand Gonseth in Bienne, Switzerland. “Science and philosophy form one body,” it stated in its founding values, “and all that happens in science, whether in its methods or in its results, may resound on philosophy even in its most fundamental principles.” This was a radical statement — equally shocking to both science and philosophy. The association published an underground newsletter called Epistemological Letters , a kind of physics “zine,” with typed, mimeographed pages speckled with hand-drawn equations that was mailed out to 100 or so physicists and philosophers who comprised a new counterculture — the daring few who wanted to discuss experimental metaphysics. Shimony served as editor.
Bell’s theorem was always at the center of those discussions, because where previous work in physics let its metaphysics go unacknowledged, in Bell’s work the two were truly and explicitly inseparable. The theorem was not about any particular theory of physics. It was what physicists call a “no-go” theorem, a general proof showing that any theory operating under the metaphysical assumptions of locality and realism can’t describe the world we live in. You want a world that just is some particular way even when it’s not being measured? And you want locality? No go. Or, as Shimony put it in Epistemological Letters , in a play on Bell’s name, those who want to hold such a worldview “should remember the sermon of Donne: ‘And therefore never send to know for whom the bell tolls; it tolls for thee.’”
“Bell was both a philosopher of physics and a physicist,” said Wayne Myrvold , a philosopher of physics at Western University in Canada. “And in some of his best papers, he’s basically combining the two.” That rattled the editors of traditional physics journals and other gatekeepers of science. “This kind of work was definitely not seen as respectable,” Cavalcanti said.
The physicist John Clauser attends to the experiment he and Stuart Freedman built to test Bell’s theorem in the 1970s.
Courtesy of Lawrence Berkeley National Laboratory
That’s why, when the French physicist Alain Aspect went to Bell suggesting a new experiment that could test Bell’s inequality while ruling out any residual influence propagating between the measurement devices used to detect the photons’ polarizations, Bell asked him whether he had a permanent faculty position. “The worry was that doing that experiment would be a career killer for a young physicist,” Myrvold said.
Fast-forward to 2022, and there’s Aspect, along with Clauser and Anton Zeilinger, headed to Stockholm to receive a Nobel Prize. Those Bell’s inequality-violating correlations have, as it turns out, led to revolutionary technologies including quantum cryptography, quantum computing and quantum teleportation. But “despite the technological payoff,” Myrvold said, “the work was motivated by philosophical questions.” According to the Nobel citation, the three physicists won for “pioneering quantum information science.” According to Cavalcanti, they won for experimental metaphysics.
BELL’S THEOREM WAS only the beginning.
In the wake of experiments violating Bell-type inequalities, several views of reality remained on the table. You could keep realism and give up locality, accepting that what happens in one corner of the universe instantaneously affects what happens in another and therefore that relativity must be modified. Or you could keep locality and give up realism, accepting that things in the universe don’t have definite features prior to being measured — that nature is, in some profound sense, making things up on the fly.
But even if you gave up on a pre-measurement reality, you could still hang on to a post-measurement reality. That is, you could imagine taking all those measurement outcomes and piecing them together into a single, shared reality. That’s typically what we mean by “reality.” It’s the very notion of an objective world.
A thought experiment posed in 1961 casts doubt on that possibility. Eugene Wigner, the Nobel Prize-winning physicist, proposed a scenario in which an observer, call him “Wigner’s friend,” goes into a lab where there’s a quantum system — say, an electron in a quantum combination, or superposition, of two states called “spin up” and “spin down.” The friend measures the electron’s spin and finds that it’s up. But Wigner, standing outside, can use quantum mechanics to describe the entire state of the lab, where, from his perspective, no measurement has taken place. The state of the friend and the state of the electron are merely correlated — entangled — while the electron remains in a superposition of states. In principle, Wigner can even perform a measurement that will show physical effects of the superposition. From the friend’s perspective, the electron has some post-measurement state, but this doesn’t seem to be part of Wigner’s reality.
In 2018, that nagging doubt about a shared reality became a full-blown dilemma. Časlav Brukner , a physicist at the University of Vienna, realized that he could combine Wigner’s friend with a Bell-type experiment to prove a new no-go theorem. The idea was to have two friends and two Wigners; the friends each measure half of an entangled system, and then each of the Wigners makes one of two possible measurements on his friend’s lab. The Wigners’ measurement outcomes will be correlated, just like the photons’ polarizations in the original Bell-type experiments, with certain metaphysical assumptions imposing upper bounds on the strength of those correlations.
Eric Cavalcanti and Nora Tischler, colleagues at Griffith University, plan experiments that use optical devices and lasers to test inequalities in experimental metaphysics.
As it turned out, Brukner’s proof relied on an extra assumption that weakened the strength of the resulting theorem, but it inspired Cavalcanti and colleagues to make their own version. In 2020, in the journal Nature Physics , they published “A Strong No-Go Theorem on the Wigner’s Friend Paradox,” which proved two things. First, that experimental metaphysics, previously relegated to underground zines, is now worthy of prestigious scientific journals, and second, that reality is even stranger than Bell’s theorem ever suggested.
Their no-go theorem showed that, if the predictions of quantum mechanics are correct, the following three assumptions cannot all be true: locality (no spooky action at a distance), freedom of choice (no cosmic conspiracy tricking you into setting your detectors so that the outcomes seem to violate Bell’s inequality even though they don’t), and absoluteness of observed events (an electron with spin up for Wigner’s friend is an electron with spin up for everyone). If you want local interactions and a conspiracy-free cosmos, then you have to give up on the notion that a measurement outcome for one observer is a measurement outcome for all.
Significantly, their no-go theorem “constrains the space of possible metaphysical theories more tightly than Bell’s theorem does,” Cavalcanti said.
“It’s an important improvement,” Brukner said. “It’s the most precise, strongest no-go theorem.” Which is to say, it’s the most powerful piece of experimental metaphysics yet. “The strength of these no-go theorems is exactly that they do not test any particular theory, but a worldview. By testing them and showing violations of certain inequalities, we don’t reject one theory, but a whole class of theories. That’s a very powerful thing. It allows us to understand what is possible.”
Brukner laments that the implications of experimental metaphysics haven’t yet been fully incorporated into the rest of physics at large — especially, in his view, to the detriment of research on the quantum nature of gravity. “This is really a pity, because we end up with wrong pictures of, say, how the vacuum looks, or what goes on in a black hole, where they are described without any reference to modes of observation,” he said. “I don’t think that we will make significant progress in these fields until we really do much work on the theory of measurement.”
Whether experimental metaphysics can ever lead us to the correct theory of quantum gravity is unclear, but it could at least narrow the playing field. “There’s a story, I don’t know if it’s apocryphal, but it’s a nice one,” Cavalcanti wrote in a 2021 paper , “according to which Michelangelo, when asked about how he sculpted David, said: ‘I just removed anything that was not David.’ I like to think of the metaphysical landscape as the raw block of marble — with different points in the block corresponding to different physical theories — and of experimental metaphysics as a chisel to carve the marble, eliminating corners that do not describe the world of our experience. It may turn out that we are unable to reduce the block to a single point, corresponding to the one true ‘theory of everything.’ But we may hope that after we carve out all the bits that experiment allows us to, what remains forms a beautiful whole.”
AS I SPOKE with Cavalcanti, I tried to get a read on which interpretation of quantum mechanics he subscribed to by feeling out which metaphysical assumptions he hoped to hang on to and which he was ready to toss. Did he agree with the Bohmian interpretation of quantum mechanics, which trades locality for realism? Was he a “ QBist ,” with no need for the absoluteness of observed events? Did he believe in the cosmic conspiracies of the superdeterminists , who attribute all correlated measurements in the present-day universe to a master plan set out at the beginning of time? How about measurements spawning parallel realities, as in the many-worlds hypothesis ? Cavalcanti kept a true philosopher’s poker face; he wouldn’t say. (The puppy, meanwhile, was waging an all-out tug-of-war against the carpet.) I did, however, catch one hint. Whatever interpretation he eventually chooses, he wants it to touch on the mystery of the mind — what consciousness is, or what counts as a conscious observer. “I still think that that is the deepest mystery,” he said. “I don’t think that any of the available interpretations actually quite get to the right story.”
In their 2020 Nature Physics paper, Cavalcanti and colleagues reported the results of what they called a “proof-of-principle version” of their Bell-cum-Wigner’s-friend experiment, which showed a clear violation of inequalities derived from the joint assumptions of locality, freedom of choice, and the absoluteness of observed events. But the experiment is inherently tricky to carry out, because something — or someone — has to play the role of an observer. In the proof-of-principle version, Wigner’s “friends” were played by photon paths, while photon detectors played the part of the Wigners. Whether something as simple as a photon path counts as an observer is notoriously hard to say.
“If you think that any physical system can be considered an observer, then the experiment has already been done,” Cavalcanti said. “But most physicists will think, no, I don’t buy that. So what are the next steps? How far can we go?” Is a molecule an observer? An amoeba? Could Wigner be friends with a fig? Or a ficus?
If the friend has to be human, it’s hard to overstate just how difficult it would be to measure one in a superposition, which is exactly what the Wigners of the experiment are supposed to do. It’s hard enough to keep a single atom in a superposition. Sustaining an atom’s superposed states means isolating it from virtually all interactions — including interactions with air — which means storing it just a hair’s breadth above absolute zero. The average adult human being, besides needing air, is made of some 30 trillion cells, each containing some 100 trillion atoms. The technology, fine motor skills and questionable ethics a Wigner would need to perform his measurement would stretch the imagination of any physicist or institutional review board. “It’s not always emphasized that this [proposed] experiment is a violent act,” Myrvold said. “It basically involves destroying the person and then reviving them.” Good luck getting the grant money for that.
Brukner, for one, wonders whether the measurement is not merely difficult, but impossible. “I suspect if we put it all down on paper, we will see that the resources required for Wigner to make this measurement go far beyond what is available in the universe,” he said. “Maybe in some more fundamental theory, these limitations will be part of the theory, and it will turn out that there is no meaning to this question.” That would be quite the twist for experimental metaphysics. Maybe our deepest insights into the nature of reality will come when we realize what’s not testable.
Cavalcanti, however, is holding out hope. We may never be able to run the experiment on a human, he says, but why not an artificial intelligence algorithm? In his newest work , along with the physicist Howard Wiseman and the mathematician Eleanor Rieffel , he argues that the friend could be an AI algorithm running on a large quantum computer, performing a simulated experiment in a simulated lab. “At some point,” Cavalcanti contends, “we’ll have artificial intelligence that will be essentially indistinguishable from humans as far as cognitive abilities are concerned,” and we’ll be able to test his inequality once and for all.
But that’s not an uncontroversial assumption. Some philosophers of mind believe in the possibility of strong AI, but certainly not all. Thinkers in what’s known as embodied cognition, for instance, argue against the notion of a disembodied mind, while the enactive approach to cognition grants minds only to living creatures.
All of which leaves physics in an awkward position. We can’t know whether nature violates Cavalcanti’s inequality — we can’t know, that is, whether objectivity itself is on the metaphysical chopping block — until we can define what counts as an observer, and figuring that out involves physics, cognitive science and philosophy. The radical space of experimental metaphysics expands to entwine all three of them. To paraphrase Gonseth, perhaps they form a single whole.
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Sally-Anne test. The Sally-Anne test is a psychological test originally conceived by Daniel Dennett, used in developmental psychology to measure a person's social cognitive ability to attribute false beliefs to others. [1] Based on the earlier ground-breaking study by Wimmer and Perner (1983), [2] the Sally-Anne test was so named by Simon ...
The traditional test for theory of mind is a false-belief task. A false-belief task is commonly used in child development research to assess a child's understanding that other people can have beliefs about the world which are not true. The false-belief task allows researchers to distinguish unambiguously between the child's (true) belief ...
1. Introduction. For almost 40 years, the explicit question in false belief tasks (FBT) of Wimmer and Perner (), in which the child must express the false belief of a character on the state of the world, has been the commonly accepted task to study the Theory of Mind (ToM).Understanding the false beliefs of others is of considerable importance for the cognitive and social development of children.
PII: S0010-0277(00)00096-2. Baron-Cohen, Tager-Flusberg & Cohen, 2000; Carruthers & Smith, 1996; Mitchell & Riggs, 2000). The `standard version' of the false belief task presents the child with a character, Sally, who leaves a desirable object such as a chocolate in her basket, before departing the scene. In her absence, another character, Anne ...
The formation of false beliefs all but requires exposure to false information. ... (and only in one of two experiments) 291, with other studies finding no evidence 112,151,222.
The false-belief test has played a pivotal role in theory of mind research in both developmental and comparative psychology over the past 30 years. Although the standard false-belief test has been challenged from various angles in both fields, and while nonlinguistic false-belief tests have become increasingly popular, debates continue with ...
The experiment also contextualized ToM processes in a simulated interaction that closely resembled face-to-face interaction and captured effects of ToM processes on objective measures of task performance. ... False-belief understanding in 2.5-year-olds: evidence from two novel verbal spontaneous-response tasks. Dev. Sci.
In the false-belief experiment of Scott and Baillargeon [4], the infants received four familiarization trials involving two toy penguins that were identical except that one could come apart (2-piece penguin) and one could not (1-piece penguin). As a female agent watched, an experimenter's gloved hands placed the 1-piece penguin and the two ...
Long before the second wave of spontaneous-response false-belief studies, Jerry Fodor argued for a modular theory of mind which would be present already in young infants.Even though three-year-olds consistently fail while four-year-olds consistently pass elicited false-belief tasks, Fodor argued that the child's theory of mind, as such, undergoes no alteration; what changes is only his ...
The results of traditional false-belief tasks suggested that false-belief understanding did not emerge until age 4 years and constituted a major milestone in the development of social cognition. ... Additional evidence against the fundamental-change view comes from experiments that tested one key prediction from the substantial-continuity view ...
Theory of mind tested by implicit false belief: a simple and full‐fledged mental state attribution. ... For example, in one experiment , infants were familiarized with an actor reaching for and grasping one of two toys (defined as the target toy). Next, the locations of the two toys were reversed, and the actor reached for the target or ...
The first experiment to provide evidence about when theory of mind emerges using a test of false beliefs was carried out by Heinz Wimmer and Josef Perner from the University of Salzburg (Wimmer & Perner, 1983). To test the emergence of 'theory of mind' the researchers wanted to find out whether children could pass a false belief test.
The Smarties Task is a subtype of false-belief tasks that is used to test for theory of mind. Introduction. The Smarties Task constitutes a by now classical paradigm often used in theory of mind experiments. In this procedure, children are shown a tube of "Smarties" (the brand name of a kind of chocolate candy) and asked to guess its ...
hold false beliefs. Most research on children's false-belief rea-soning has utilized some variant of the displacement task (e.g., Baron-Cohen, Leslie, & Frith, 1985; Wimmer & Perner, 1983). For example, subjects are told a story about Sally, who puts her candy in a box and leaves the room. In her absence, another character moves the candy to ...
In this Wireless Philosophy video, Liang Zhou Koh talks about the false belief task, an experiment designed to test for our capacity to mindreading.Check out...
Classically, children come to understand beliefs, including false beliefs, at about 4-5 y of age, but recent studies using different response measures suggest that even infants (and apes!) have some skills as well. Resolving this discrepancy is not possible with current theories based on individual cognition.
In these experiments, an agent has a false belief concerning the location of a desired object, a false belief induced in a similar way to the one induced in typical FBTs. The children then exhibit indications of surprise when the agent goes to where, unbeknownst to him, the desired object in fact is, but not ...
Having theory of mind means understanding how others think, including the ability of someone else to have a false belief. In a famous theory-of-mind experiment that includes false beliefs, children watch scenes involving a character named Maxi, his mother and a chocolate bar. Maxi places the chocolate bar into a blue box and then leaves.
The experiment comprised two main parts presented in a fixed order: an spontaneous ToM task and an explicit version of the same task. ... Thus, the agent could rightly believe the ball not to be behind the occluder. (iii) In the False Belief-Positive Content condition (P− A+), the order of when the ball and the agent left the scene was ...
1. Introduction. For almost 40 years, the explicit question in false belief tasks (FBT) of Wimmer and Perner (1983), in which the child must express the false belief of a character on the state of the world, has been the commonly accepted task to study the Theory of Mind (ToM).Understanding the false beliefs of others is of considerable importance for the cognitive and social development of ...
Here, we discuss the different theoretical frameworks of insight, belief change, and the neuropharmacology of psychedelics and present an integrated model for how psychedelics can engender false ...
Implication of False Belief Experiments 2. {A} A considerable amount of research since the mid-1980s has been concerned with what has been termed children's theory of mind. This involves children's ability to understand that people can have different beliefs and representations of the world-a capacity that is shown by four years of age.
A gorilla-suit experiment reveals our closest animal relatives may possess "theory of mind" ... Traditional false-belief tests for apes have involved complicated tasks such as moving around ...
Advanced Artificial Intelligence (AI) systems, specifically large language models (LLMs), have the capability to generate not just misinformation, but also deceptive explanations that can justify and propagate false information and erode trust in the truth. We examined the impact of deceptive AI generated explanations on individuals' beliefs in a pre-registered online experiment with 23,840 ...
Experiments that test physics and philosophy "as a single whole" may be our only route to surefire knowledge about the universe. ... For Bell, those assumptions are typically understood to be locality (the belief that things can't influence each other instantaneously across space) and realism (that there's some way things simply are ...