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本城市有一個以「科學方法」為主題的專欄(關於科學方法的討論)。本欄則轉貼我認為近於「胡言亂語」的「學術」論文或研究報告。它們是 how not to do research的範例。先轉貼兩篇我最近看到的介紹以及一篇論文。



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Rathi先生介紹Peter Turchin Thomas Currie兩位教授的研究及其報告。後者的結論:


Their computer simulations show that warfare may have been the main driver behind the formation of empires, bureaucracies and religions.




「戰爭」一詞通常指大規模的武裝衝突,如:He may have won the battle but lost the war.


要進行「大規模武裝衝突」的前提是中央政府、行政體系、和某種凝聚民眾情緒的意識形態,也就是Rathi先生所引述的empires, bureaucracies, and religions.沒有這些前置條件,則「競爭」可能只會以隨機衝突的形式進行,如狗搶骨頭或村民械鬥。


中央政府、行政體系、和意識形態的「形成」也有其前置條件,即在維持生活基本需要以外的「多餘資源」或「豐裕資源」。因此,我比較傾向接受Jared Diamond教授所提出「農業」(agriculture)是促成文化演進的主要因素。,在「農業社會」形成一段時間後,James Robinson教授所提出的「社會制度」(social institutions)才得以逐漸形成。有效率的各種「社會制度」自然幫助文化的演變和進步。然後才能建立歷史上的「帝國」,這些「帝國」才能組織軍隊和製造武器,戰爭才有發生的機會。




Peter Turchin Thomas Currie兩位教授這個研究的思考模式是英語俗話所描述的:


「把馬車的車身放到馬的前面。」 (Put the cart in front of the horses.)



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思想在那裏發生?不只在大腦 - C. Aschwanden



Where Do Thoughts Occur?            


Sure, your brain is a wonder. But some cognitive scientists argue that without the help of your body, your brain would be nowhere.


Christie Aschwanden, Discover June 2013 issue


We think big. We think out loud. We think outside the box. We think on our feet. But what we don’t do is think entirely inside our heads. Thoughts aren’t confined to our brains -- they course through a network that expands to our bodies, perhaps eliminating, at times, the need for complex thought.


The notion that we think with the body -- the startling conclusion of a field called embodied cognition -- flies in the face of long-standing views. Early cognitive psychologists defined thought as an activity that resides in the brain: Sensory data come in from eyes and ears, fingers and funny bone, and the mind turns these signals into disembodied representations that it manipulates in what we call thinking. 


Sure, the body may collect sensory information, like a computer collects information via mouse and keyboard, but according to the traditional view of cognition, it’s the brain that does the thinking.


But dozens of studies over the past decade challenge that view, suggesting instead that our thoughts are inextricably linked to physical experience. As University of Toronto psychologist Spike Lee puts it, bodily states “aren’t some extraneous thing -- they’re part of the thinking process.” 


In one study, Lee and a colleague exposed volunteers to different odors. When they did, they found that getting a whiff of a fishy odor evoked feelings of suspicion; likewise, when research participants were exposed to another person behaving suspiciously, they were better able to detect a fishy scent. 


The range of findings demonstrating embodied cognition is impressive. A small sampling: Looking upward nudges people to call to mind others who are more powerful, while looking down prompts thoughts of people we outrank. 


People judge a petition to be more consequential if it is handed to them on a heavy clipboard rather than a lightweight one. Baseball players with high batting averages perceive the ball as bigger than poorer hitters. And Botox injections that prevent frowning also slow people’s comprehension of sentences describing angry and sad events.


Thinking Is for Doing


On their surface, findings like these seem like mere fodder for amusing cocktail conversation: “The body biases thought, you say? Hmm, weird. Pass the guacamole.” But some cognitive scientists argue the evidence points to something far deeper and more radical. It’s not just that our bodies influence thought: It’s that thought itself is a system that simultaneously takes place in the brain, the body and the environment around us. 


In fact, we fundamentally perceive the world in terms of our ability to act on our environment, says Sabrina Golonka, a cognitive psychologist at Leeds Metropolitan University in the United Kingdom. “We’re not seeing the world in inches and feet -- we’re seeing the world in arm units or leg lengths,” she says. 


In one study, researchers at the University of Virginia asked volunteers to estimate the steepness of a hill just by looking at it from the bottom. The volunteers’ answers correlated with how physically suited they were to climbing the hill: They rated the hill as steeper when they wore a heavy backpack, and likewise, athletes described the hill as less steep than volunteers who were unfit.


The body’s influence over our perceptions is more than just academic -- it could have serious consequences in high-stakes situations, argues Jessica Witt, a psychologist at Colorado State University. She wondered if embodiment could help explain tragic misperceptions such as the 1999 shooting of Amadou Diallo, who was killed by New York police officers who perceived Diallo’s motioning to open his wallet as the brandishing of a gun. 


To investigate, Witt and a colleague showed college students photos of people holding different objects and asked them to quickly decide whether what they saw was a gun or some neutral object, like a shoe or a cell phone. 


When participants were themselves holding a plastic toy gun, versus some neutral object, they were about 30 percent more likely to perceive the object in another person’s hand as a gun. Merely seeing a gun nearby had no such effect on their perceptions. 


“We see the world in terms of our ability to act,” Witt concludes. The same object “can look different, depending on what we’re intending to do and our ability to perform that intended action.”


Different Bodies, Different Thoughts?


Such findings raise a mind-bending question: Do different bodies dictate different thoughts? In one study that confronts that idea, cognitive scientist Daniel Casasanto of the New School for Social Research in New York reasoned that if people use their physical perceptions and motor experiences to construct mental simulations, then physical characteristics that cause us to interact with the environment in systematically different ways should in fact send people down different mental pathways.


To test the possibility, Casasanto and colleagues examined spatial preferences in left- and right-handers. He found that people prefer the choices presented to them on their dominant side, a phenomenon that supports what he calls the “body-specificity hypothesis.” When asked to select which job applicant to hire, which product to buy or which alien creature seemed most trustworthy, lefties tended to choose the selection that was on the left, and vice versa. 


In another experiment, Casasanto’s team asked right-handed study participants to wear a bulky glove that nudged them to use their left hand while doing a motor task. The constraint changed their preferences: After completing a motor task with their left hand, people preferred choices presented on their left. 


Studies that demonstrate embodied cognition seem to defy conventional wisdom, which paints thought as a set of computer-like algorithms that unfold entirely within the skull. That characterization is a mistake, Golonka argues. 


She and Leeds colleague Andrew Wilson advocate an ecosystem-like approach that treats even the most sophisticated cognitive tasks as a product of how our brains and bodies have evolved with our environments. The astonishing implication is that our bodies, through perception and action, can actually replace the need for complex mental calculations. 


Consider a baseball outfielder who must run to catch a fly ball: How does he get to the right place at the right moment? You could solve this problem with a calculator, using math and physics to calculate where and when the ball would reach the height necessary for catching, and then draw a straight line from the player’s starting position to that spot. But the player doesn’t do the math, and he doesn’t run in a straight line, Golonka says. 


Instead, he keeps his eye on the ball and moves in a path that syncs with the ball’s curved, decelerating trajectory. As he runs, his motion cancels out some of the ball’s motion and now it looks, to him, as if the ball is moving in a straight line, which he can track to its endpoint. 


The outfielder doesn’t need to get out a calculator. He just needs to process the visual cues he’s getting, along with physical cues like his running speed, and then put them together to solve the task. Yes, he uses his brain; but his eyes and legs are just as crucial.


Clear evidence of embodied cognition is now voluminous. What to make of it ... well, that’s more controversial. The view that thought depends crucially on bodily sensation and action has yet to overtake the traditional model of cognition, as Lee observes. In part, that’s because researchers lack a coherent theory that can explain how and under what circumstances embodied effects occur. 


Golonka and Wilson hope their ecosystem-like model can become this unifying framework. If they’re right that thought occurs not only in the brain but in a tangled communication among brain, body and environment, it could turn cognition research upside down. French philosopher René Descartes once said, cogito ergo sum: I think, therefore I am. 


The embodied cognition model suggests a slightly different philosophy -- I am, therefore I think.



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人真的有自由意志嗎?當然有 - R. F. Baumeister


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Do You Really Have Free Will?


Of course. Here’s how it evolved.


Roy F. Baumeister, 09/25/13


It has become fashionable to say that people have no free will. Many scientists cannot imagine how the idea of free will could be reconciled with the laws of physics and chemistry. Brain researchers say that the brain is just a bunch of nerve cells that fire as a direct result of chemical and electrical events, with no room for free will. Others note that people are unaware of some causes of their behavior, such as unconscious cues or genetic predispositions, and extrapolate to suggest that all behavior may be caused that way, so that conscious choosing is an illusion.


Scientists take delight in (and advance their careers by) claiming to have disproved conventional wisdom, and so bashing free will is appealing. But their statements against free will can be misleading and are sometimes downright mistaken, as several thoughtful critics have pointed out.  


Arguments about free will are mostly semantic arguments about definitions. Most experts who deny free will are arguing against peculiar, unscientific versions of the idea, such as that “free will” means that causality is not involved. As my longtime friend and colleague John Bargh put it once in a debate,


“Free will means freedom from causation.”


Other scientists who argue against free will say that it means that a soul or other supernatural entity causes behavior, and not surprisingly they consider such explanations unscientific.


These arguments leave untouched the meaning of free will that most people understand, which is


consciously making choices about what to do in the absence of external coercion, and accepting responsibility for one’s actions.


Hardly anyone denies that people engage in logical reasoning and self-control to make choices. There is a genuine psychological reality behind the idea of free will. The debate is merely about whether this reality deserves to be called free will. Setting aside the semantic debate, let’s try to understand what that underlying reality is.


There is no need to insist that free will is some kind of magical violation of causality. Free will is just another kind of cause. The causal process by which a person decides whether to marry is simply different from the processes that cause balls to roll downhill, ice to melt in the hot sun, a magnet to attract nails, or a stock price to rise and fall.  


Different sciences discover different kinds of causes. Phillip Anderson, who won the Nobel Prize in physics, explained this beautifully several decades ago in a brief article titled “More is different.” Physics may be the most fundamental of the sciences, but as one moves up the ladder to chemistry, then biology, then physiology, then psychology, and on to economics and sociology -- at each level, new kinds of causes enter the picture.


As Anderson explained, the things each science studies cannot be fully reduced to the lower levels, but they also cannot violate the lower levels. Our actions cannot break the laws of physics, but they can be influenced by things beyond gravity, friction, and electromagnetic charges. No number of facts about a carbon atom can explain life, let alone the meaning of your life. These causes operate at different levels of organization. Even if you could write a history of the Civil War purely in terms of muscle movements or nerve cell firings, that (very long and dull) book would completely miss the point of the war. Free will cannot violate the laws of physics or even neuroscience, but it invokes causes that go beyond them.


The evolution of free will began when living things began to make choices. The difference between plants and animals illustrates an important early step. Plants don’t change their location and don’t need brains to help them decide where to go. Animals do. Free will is an advanced form of the simple process of controlling oneself, called agency.


The squirrel is more complex than the tree, and it does plenty of things the tree can’t. When chased by a dog, the squirrel needs to choose which direction to run. Its decision processes may be simple, but it does choose, nonetheless. Thousands of lab studies have shown how rats learn to make choices that bring them rewards. How did this simple agency evolve into the more complex style of choosing that people call free will?


Living things everywhere face two problems: survival and reproduction. All species have to solve those basic problems or else go extinct. Humankind has an unusual strategy for solving them: culture. We communicate, develop complex social systems, engage in trade, accumulate knowledge collectively, create giant social institutions (governments, hospitals, universities, corporations). These help us survive and reproduce, increasingly in comfortable and safe ways. These large systems have worked very well for us, if you measure success in the biological terms of survival and reproduction.


If culture is so successful, why don’t other species use it? They can’t -- because they lack the psychological innate capabilities it requires. Our ancestors evolved the ability to act in the ways necessary for culture to succeed. Free will likely will be found right there -- it’s what enables humans to control their actions in precisely the ways required to build and operate complex social systems.


What psychological capabilities are needed to make cultural systems work? To be a member of a group with culture, people must be able to understand the culture’s rules for actions, including moral principles and formal laws. They need to be able to talk about their choices with others, participate in group decisions, and carry out their assigned role. Culture can bring immense benefits, from cooked rice to the iPhone, but it only works if people cooperate and obey the rules.


If you think of freedom as being able to do whatever you want, with no rules, you might be surprised to hear that free will is for following rules. Doing whatever you want is fully within the capability of any animal in the forest. Free will is for a far more advanced way of acting. It’s what a creature might need in order to adjust its behavior to novel situations, to get what it wants while still following the complicated rules of the society.


People must inhibit impulses and desires and find ways of satisfying them within the rules. People also consciously imagine various future scenarios (“If I do this, then that will happen, whereupon I would do something else, leading to another result …”) and guide their present actions based on disciplined imagination.


That, in a nutshell, is the inner deciding process that humans have evolved. That is the reality behind the idea of free will: these processes of rational choice and self-control. It’s this or nothing. If you accept free will, this is what it is. If you insist on disbelieving in free will, these are the processes that are commonly taken for it. But either way, there is a real phenomenon here. And to understand human life, it is vital to understand how this phenomenon works.


Does it deserve to be called free? I do think so. Philosophers debate whether people have free will as if the answer will be a simple yes or no. But very few psychological phenomena are absolute dichotomies. Instead, most psychological phenomena are on a continuum. Some acts are clearly freer than others. The freer actions would include conscious thought and deciding, self-control, logical reasoning, and the pursuit of enlightened self-interest.


Self-control counts as a kind of freedom because it begins with not acting on every impulse. The simple brain acts whenever something triggers a response: A hungry creature sees food and eats it. The most recently evolved parts of the human brain have an extensive mechanism for overriding those impulses, which enables us to reject food when we’re hungry, whether it’s because we’re dieting, vegetarian, keeping kosher, or mistrustful of the food. Self-control furnishes the possibility of acting from rational principles rather than acting on impulse.


The use of abstract ideas such as moral principles to guide action takes us far beyond anything that you will find in a physics or chemistry textbook, and so we are free in the sense of emergence, of going beyond simpler forms of causality. Again, we cannot break the laws of physics, but we can act in ways that add new causes that go far beyond physical causation. No electron understands the Golden Rule, and indeed an exhaustive study of any given atom will furnish no clue as to whether it is part of a person who is obeying or disobeying that rule. The economic laws of supply and demand are genuine causes, but they cannot be reduced to or fully explained by chemical reactions. Understanding free will in this way allows us to reconcile the popular understanding of free will as making choices with our scientific understanding of the world.


Roy F. Baumeister is an eminent social psychologist with over 500 scientific publications, plus 31 books, including a New York Times best-seller, Willpower



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戰爭促進各地區文明的產生 - A. Rathi


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War Drove the Rise of Civilizations


Akshat Rathi, 09/25/13


Editor's Note: This article was provided by The Conversation UK. The original is here.


According to British historian Arnold Toynbee, “History is just one damned thing after another.”


Or is it? That is the question Peter Turchin of the University of Connecticut in Storrs tries to answer in a new study just published in the Proceedings of the National Academy of Sciences. He and his colleagues show history may be deterministic, at least to a certain extent. Their computer simulations show that warfare may have been the main driver behind the formation of empires, bureaucracies and religions.


Historians may be a bit leery about scientists making this sort of attempt, since history is driven by a complex set of events, some of them seemingly one-time only. But Turchin thinks otherwise. Through an approach he calls cliodynamics (named after Clio, the Greek muse of history), he wants to unravel the past by testing hypotheses against data.


For his latest work, he joined with Thomas Currie, a lecturer in cultural evolution at the University of Exeter. In the new study, they use a computer simulation to model the largest societies in the years between 1500 BCE and 1500 CE.


Their model uses a map of Africa and Eurasia split up into cells that are 100 kilometres on each side. The properties of each cell are its natural landscape, height above sea level and the possibility of agriculture (which was the main driving force behind societies). The borders are seeded with military technology, starting with the use of horses. That technology then spreads as societies fight it out virtually. What emerges is the probability that each cell of land could or could not be occupied by civilisations as time progresses. (Note: Red depicts higher probability of existence of a civilisation and green lower.)




“Remarkably, when the results from the simulation are compared with real data from the past, the model predicts the rise of empires with 65% accuracy,” Currie said. If military technology is removed as a factor, the model’s accuracy falls to a mere 16%. “It seems warfare created intense pressure that drove these societies.”


Other researchers such as Jared Diamond and James Robinson have suggested, respectively, that agriculture and social institutions drove civilisations. They undoubtedly contributed, but Turchin and Currie argue that their results show that competition through warfare may have played a more important role.


Peter Richerson, emeritus professor at the University of California at Davis, studies cultural evolution and is impressed by cliodynamics. “It is early days yet, so the specific hypothesis tested here is liable to prove wrong or at least incomplete,” he said. “The model fails to predict the emergence of large empires in Central Asia. Something not in the current model is going on there.”


Currie agrees. “Our results are a good fit because of the broad scale. We are aware we are glossing over many complexities,” he said. Still, there is lots of potential value in building these models. The global database of historical events has many gaps. With efforts underway to grow these databases through all the information that historians, archaeologists and social scientists can find, the models are bound to get better.


The Conversation

Akshat Rathi is science and technology editor at The Conversation UK.



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