Bias as usual? Or fair play?

David Stern, commissioner of the National Basketball Association, isn’t too happy with the recent revelation that N.B.A. referees appear to have a racial bias in the way they call fouls. He’s questioned the validity of the statistical analysis by Justin Wolfers, an assistant professor of business and public policy at the Wharton School, and Joseph Price, a Cornell graduate student in economics, which suggests that white and black referees call fouls preferentially against players of the opposite race. The N.B.A. insists that its own analysis (of different data) reveals no such bias, although other experts who’ve seen both analyses say that the Wolfers and Price study is more convincing.

But I wonder if Stern and the N.B.A. wouldn’t be better off with a different tactic. A finding of this kind may make for scandalous headlines, but it isn’t really all that surprising, and takes its place in an already sizable literature showing that racial bias often works more or less unconsciously, that even its perpetrators often remain completely unaware of it. The fact that it took sophisticated mathematical analysis even to identify the bias, and that neither N.B.A. fans nor players appear to perceive it, suggests that maybe the N.B.A. isn’t doing such a bad job (though not that they shouldn’t try harder).

Psychologists have demonstrated that even children as young as three years old already attribute lasting and special significance to skin color, which they see as more fundamental than clothing styles, for example, or profession. They’re not surprised that someone might change clothes or the kind of work they do, but do not consider it credible that someone might change his or her race.

Most adults seem to have similarly automatic responses to race, with built-in biases. A few years ago, for example, one brain-imaging study of adults found that both white and black subjects, when presented with faces of the other race, showed increased activity in the amygdala, a brain region that typically responds to stimuli that have emotional significance. The subjects, meanwhile, reported feeling no particular emotion in connection with the different faces. Another study, this one of white subjects only, found that those whose amygdalas were most active also scored highest on a standard test for racial prejudice.

These studies were and are highly controversial (what’s not in this area?), and the scientists behind them quite rightly argue that they should be interpreted with care. After all, having these unconscious reactions doesn’t mean that people will act on them.

Still, this evidence strongly suggests that racial differences influence human behavior at a very primitive and unconscious level. Hence, it’s hardly surprising that N.B.A. officials, making split-second decisions on rapidly moving events under tremendous pressure, might succumb – weakly, the statistics suggest – to some kind of automatic and unconscious bias.

That’s not to say that bias of this kind is acceptable, that it’s ineradicable and that we just have to live with it. Far from it. The point is that understanding our natural biases – and their sometimes counterintuitive origins – may ultimately give us a better chance to take measures to mitigate their damaging consequences.

For many years, psychologists thought that people categorize others automatically along three lines – by age, sex and race. Numerous experiments, including those already mentioned, seem to show as much. But six years ago, anthropologists Robert Kurzban, John Tooby and Leda Cosmides of the University of California, Santa Barbara, suggested that this idea has deep problems, at least when it comes to race. That’s because through most of evolutionary history, people were not exposed to other races. So there was no way for any kind of hard-wired racial sensitivity to evolve.

Instead, they argue, the experimental finding that people do categorize by race, automatically and rapidly, arises as a kind of accident. What our ancestors did need to be able to do – and there were potentially deadly consequences if they got it wrong – was to identify the groups or coalitions to which people belonged. Is the stranger walking into camp part of my tribe, or an enemy?

To make such decisions, the argument goes, people naturally latched onto whatever clues were available, including style of clothing or skin color. This would be little more than a nice theory if the three authors hadn’t also backed it up with some further experiments.

To test the idea, they had volunteers look at photos of blacks and whites, and manipulated cues that gave volunteers information about the peoples’ group affiliations, so that the apparent coalitions among them went not along racial divisions, but across them. In this case, they found, the power of racial categorization quickly decreased, as it was replaced by awareness of the true coalitional boundaries.

The conclusion was that racial awareness isn’t innate; group awareness is. Unfortunately, in today’s world, perceived coalitions often run along racial or ethnic lines, and so coalitional perception takes on the form of racial or ethnic perception.

A paradoxical element of this view is that racial discrimination emerges more or less from the same instincts that support natural group identification, which almost certainly played a huge role in helping our ancestors to form strong and cohesive groups. You’ve got to wonder, with these influences being so automatic, whether the N.B.A. is really doing worse than anyone else.

Perhaps bias in the N.B.A. has been discovered only because sports naturally generates the kind of data easily susceptible to mathematical analysis. Social researchers starved for good data naturally look for the low-hanging fruit first. The same influences may be far more pervasive, yet very difficult to demonstrate mathematically.

The really difficult question, for Stern and the rest of us, is what any organization or society can do about racial bias, given that it is so deeply rooted as to influence the behavior even of people who profess to be and truly believe they are fair-minded.

The roots of ethnic violence

One week ago, the International Criminal Court in The Hague issued arrest warrants on charges of war crimes and crimes against humanity for Ahmad Muhammad Harun, Sudan’s former interior minister who oversaw the Darfur Security Desk, and Ali Muhammad Ali Abd-al-Rahman, a leader of the Janjaweed militia. Mr. Harun is now Sudan’s minister of humanitarian affairs. The two men seem to be rather small fry compared to Omar Hassan al-Bashir, the Sudanese president, but it’s a step in the right direction. Too little, too late, of course, for the hundreds of thousands who’ve been tortured, raped and murdered in the Darfur region over the past four years.

The question, as always, is why African and Western governments have been so painfully slow in bringing pressure against the Sudanese government, which might have stopped the killing years ago. Unfortunately, the pattern is all too familiar: as Samantha Power documented in her powerful book “A Problem From Hell,” the history of genocide in this century is one of governments, including the United States, responding almost habitually with denial and delay, with excuses and inaction.

Why? Governments, no doubt, have their own secret and not always admirable reasons for staying out. Most people, I suppose, find it hard even to imagine these things happening, as they lie so far outside our personal experience.

But the failure also stems, I suspect, from a deep misunderstanding of the origins of ethnically-targeted violence – and of the way individuals in the right positions can exploit the power of social patterns for their own selfish ends. From the Turkish slaughter of Armenians in the early 20th century through Rwanda and the former Yugoslavia, genocide has erupted almost never as a spontaneous orgy of mass killing, but always a result of political calculation and orchestration.

Before the massacre in Rwanda, for example, radio stations and newspapers owned by a handful of government officials began referring to the Tutsi as “subhuman.” The government funded and organized radical Hutu groups that amassed weapons and trained people as killers.

There was no spontaneous social uprising. The fate of one million Tutsis had been planned and prepared by April 6, 1994, when a plane carrying the Rwandan president and the Hutu president of Burundi was shot down in Kigali.

Ten years ago, a group of noted experts in sociology and psychology met in Northern Ireland to discuss the roots of genocide, and they concluded that most of the ethnopolitically motivated killings in the 20th century could be traced not to “spontaneous popular actions,” but to “dominant state elites trying to maintain their nations’ unity and their own monopoly on power.”

But this understanding is complete only if we see that leaders aren’t able to do anything they like. They wield power by stirring up social patterns and directing them for their own ends. Unfortunately, we humans are in many ways almost pre-programmed to make this possible.

In natural ethnic groups, of course, ethnocentrism is a universal phenomenon, with people everywhere convinced in no uncertain terms that their culture is superior. This isn’t just a characteristic of the uneducated; ethnocentrism presumably finds its roots in the structure of the human mind, and in the evolutionary experience of our hunter-gatherer ancestors who lived in small groups.

More surprising yet, a readiness for group-level prejudice may also be linked to the collective mechanisms that support human cooperation. On the basis of computer simulations in recent years, political scientists Ross Hammond of the Brookings Institute and Robert Axelrod of the University of Michigan suggest that in especially primitive social conditions – when people have limited opportunities to use reputation or character as a guide to someone’s trustworthiness – raw prejudice, based on crude ethnic markers, can actually be beneficial.

Roughly speaking, Hammond and Axelrod found that ethnic prejudice – again, only in these primitive conditions – helps to organize people into homogeneous ethnic groups within which interaction is easy and mostly cooperative, while minimizing the more difficult and often costly interactions between groups. Without prejudiced behavior, you would not get as much cooperation.

The conclusion is that ethnocentrism, while it may be ugly, also may be effective. The researchers suggest that it may be no coincidence that ethnic divisions and tensions tend to become enhanced and more influential in conditions of economic
collapse or when war tears apart the social fabric.

Sadly, it is our innate preparedness for ethnocentric behavior that politicians such as Slobodan Milosevic – or President Bashir today – use so effectively. In 2003, when various African tribes began rebelling in Darfur, Bashir responded by arming irregular militias and directing them to attack black civilians indiscriminately. Many of the militiamen were of Arabic descent, driven and motivated by powerful ethnic prejudice.

Historians once argued over whether individuals or social forces control history. The truth is that both are important. An individual can “pluck the strings” of a social pattern much as a musician would those of a guitar, and wield power far beyond his own personal being.

This abstract understanding does nothing to lessen the unspeakable suffering of the millions of people with names and faces and dreams whose lives have been and are being ruined or cut short. But it should alert us that genocide is not the direct consequence of unstoppable age-old hatreds, but that of people in power who use their influence to stoke hatred for strategic purposes.

It is only these people who need to be stopped.

How order creates itself

An anonymous commenter in the New York Times, responding to my previous columns, suggested that my title “Our Lives as Atoms” (this is the title under which these posts appear in the NYT) is "more than a little puzzling,” and wondered “Where will all this lead us?” I’ve written about the amplified polarization of opinion in the political blogs, and about the abuse at Abu Ghraib prison, which had a disturbingly eerie resemblance to famous experiments at Stanford University 36 years ago. What does any of this have to do with atoms? Fair question. I’d like to start my answer by telling you about a strange phenomenon in Spitsbergen.

Spitsbergen is a Norwegian island in the Svalbard archipelago. It has spectacular mountains, abundant glaciers and desolate tundra, where stones are littered over a flat and mostly featureless terrain. In places on this tundra, the stones are arranged in a remarkable way; they lie not in a chaotic, haphazard jumble but in an ordered array of hauntingly beautiful, nearly perfect circular piles. You really have to look at a photo to believe it.

Where do these stone circles come from? Some might suspect the activity of intelligent agents, the local people, perhaps. But in fact, these circular piles arise all on their own by a natural process, with no human intervention. As geophysicists Mark Kessler and Brad Werner first explained a few years ago, forces associated with freezing and thawing push the stones into stretched-out piles, and then curve the long piles around (at least sometimes) to form complete rings.

Our human intuition is ill-prepared to understand such “spontaneous order” in the physical world. Suppose you put some sand in a shallow box with a lid and shake it up and down. Will anything interesting happen? Most people think not. But when physicist Harry Swinney and colleagues at the University of Texas at Austin did this experiment a few years ago – O.K., they used millions of tiny ball bearings rather than sand – they found something very surprising. When the frequency of shaking speeds up and exceeds a certain limit, beautiful wave-like patterns form in the box.

Such spontaneous order is caused by feedback. A little pattern, even if it arises quite by accident, sets up forces that reinforce the pattern. A little clumping of stones on the tundra triggers physical reactions that lead to more clumping, and eventually to stone piles.

This still says nothing about what our lives have to do with atoms. But bear with me a tiny bit further.

The physical world contains lots of kinds of stuff – liquids and solids, metals that conduct electricity and rubber that doesn’t, semiconductors and superconductors, liquid crystals and magnets. These things are made of different kinds of atoms, but that’s not the only reason why they’re different from one another. One of the most important lessons of modern physics is that the way things are organized sometimes matters more than what they are made of. The same carbon atoms that make soft, dull graphite also make sparkling and super-hard diamond. Organization matters.

Which returns me to the mysterious title, “Our Lives as Atoms.” It may be a crude analogy, but people are akin to “atoms” in that we are the elementary building blocks of the social world. Although we tend to think of ourselves as individuals making up our own minds, we’re obviously influenced by what others around us do. Social patterns routinely emerge that have little to do with the character of individual people.

In June 2000, on the afternoon of the opening of the London Millenium Bridge, the first pedestrian bridge built across the Thames River in central London for more than a century, a policemen noticed the bridge begin to sway from side to side. Authorities quickly herded the people off and shut the bridge. What had caused the problem? The best explanation is that people’s feet, simply by walking, had set up a weak vibration in the bridge, a gentle swaying, which created feedback.

To keep their balance, people found it easier to adjust their gait and walk in time with the sway. But this amplified the motion. The more the bridge swayed, the more people adjusted their gait, making the bridge sway even more, until it was swinging several inches to either side. It was spontaneous order indeed, and of a rather dangerous kind.

This is a nice metaphor for how individual actions work together to create larger social forces. We don’t ordinarily think this way, I suspect, because our inner voice usually explains things in terms of narratives that refer to peoples intentions, thought processes and so on.

But it would be a very strange world indeed if the basic logic of spontaneous order didn’t affect us – possibly at many levels – in the way we think, the opinions we have, the clothes we wear, our political beliefs, what we do for a living and so on. In my first two columns, I looked at how individual psychology feeds into the mechanisms of the Web to create and amplify polarized opinions, and how the situation at Abu Ghraib prison, like situations in thousands of other prisons worldwide, set up the preconditions that made abuse more likely, perhaps even predictable.

I hope that clears up the connection to atoms, for Anonymous or anyone else. Maybe this column should have been the first one, but then, that’s the way the human mind works – trial and error. And ideally, correction.

The illusion of a nation divided

We seem to be a rather polarized country. According to views often expressed in the media, especially online, Republicans revel in the idea of torture and detest our Constitution, while Democrats want to bring the troops home from Iraq only to accomplish the dastardly double-trick of surrendering our country to the terrorists and kicking off a genocide in the Middle East.

It’s odd then that recent polls actually show 60 percent of Americans wanting to see the troops come home from Iraq either immediately or within a year. Another poll has 90 percent of Democrats, 80 percent of independents, and 60 percent of Republicans agreeing that global warming is a serious problem and that we as a nation should be a global leader in doing something about it. Studies show that when it comes to issues ranging from health care to the death penalty, from immigration to Social Security, people in the so-called red and blue states hold remarkably similar views.

Still, the illusion of a nation divided persists, and one reason that it does may be oddly mechanical. It’s quite possible that the emergence of visibly polarized views in the media, especially on the Internet, may be an almost automatic result of the relatively simple rules by which opinions and attitudes propagate through human heads.

Before I explain, I’d like to bring up what might seem to be a separate issue, racial segregation.

In the early 1970s, it was taken for granted among American academics that persistent racial segregation was due mostly to racism. Studies had revealed widespread racial bias in hiring, promotion and pay, and real estate practices that worked to keep blacks out of white neighborhoods. But Thomas Schelling, an economist then at Harvard, suggested that another factor might also be at work.

Schelling supposed that many people, even those who are perfectly happy to live in an integrated neighborhood, might also prefer not to live in one where they were part of an extreme minority. You wouldn’t think this simple preference could have much influence, but it can. Moving coins representing people around on a grid of squares representing houses, Schelling showed that the simple preference not to live in an extreme minority should generally lead people to move about in such a way that a community ends up segregated into distinct, racially segregated enclaves.

No one would come to this counterintuitive insight by sitting in an armchair, philosopher-like, and thinking about it. Schelling found it by way of an experiment, in his case with coins and paper, though today researchers can demonstrate the same effect using computers. The important conclusion isn’t that racism is unimportant; there is no question that it is. The point is that segregation by itself doesn’t imply racism; segregation might well arise quite automatically, the races separating like oil and water. Racism is real, but so is the automatic segregation effect, and we should be aware of both.

What does this have to do with our polarized political world? Just after the 2004 election, a pair of mathematicians undertook a study of how blogs link to one another. Imagine all the blogs on the Web as points on a page, colored red or blue depending on their political slant. Now draw a line between any two if one of them links to the other. Doing this, Lada Adamic and Natalie Glance found that the red and blue bloggers belonged to strongly separated communities, within which there were many links between like-minded sites. In contrast, there were very few links connecting the red community to the blue. (The original paper has a nice diagram of the two communities, showing the links within and between them.)

This intellectual segregation of the like-minded into separate enclaves persists today. And it is almost certain that it can be explained by the operation of a process like Schelling’s.

People experience real psychological discomfort – psychologists call it “cognitive dissonance” – when confronted with views that contradict their own. They can avoid the discomfort by ignoring contradictory views, and this alone brings like-minded bloggers together.

Humans share another psychological habit too – a strong tendency to adopt, even if unconsciously, the attitudes of those with whom they interact. We even copy other people’s behavior patterns.

In experiments at the University of Amsterdam, psychologist Ap Dijksterhuis had two separate groups of volunteers talk with some actors who behaved as either professors (supposedly intelligent) or soccer hooligans (supposedly not so smart). Afterwards, when the subjects were asked to answer a series of general knowledge questions, the people who had been “primed” by interaction with the “professors” did significantly better than those primed by the “hooligans.”

If just being around people who act “smart” or “stupid” can make us act similarly, goodness knows what automatic influences percolate through the more extreme regions of the blogosphere.

Our largely unconscious psychological mechanisms appear to support a kind of mechanical feedback that cannot easily lead to anything but a pronounced segregation into polarized enclaves, with attitudes and opinions amplifying themselves and reverberating within the confines of two distinct halls of mirrors. None of which, obviously, is conducive to healthy public discourse, nor supportive of any kind of reasoned and balanced consideration of issues.

The trouble is that these forces operate outside of our view. Many people, not by choice but more or less automatically, filter reality in an emotional way that preserves and supports the groups to which they feel linked.

The good news is, we’re not all bloggers – yet. And the American public still shows a more balanced range of opinion, much of it squarely in the middle, than one would guess from looking at the polarized blogosphere.

How people turn monstrous

It is four years and a few days since CBS News published the first photos documenting the systematic abuse, torture and humiliation of Iraqi prisoners at Abu Ghraib prison. The Bush administration and the American military have worked hard to firmly establish the “few bad apples” explanation of what happened. Eight low-ranking soldiers were convicted, and Staff Sargent Ivan Frederick II, who was found guilty of assault, conspiracy, dereliction of duty and maltreatment of detainees, is now halfway through his eight-year prison sentence.

But there are very good reasons to think that Frederick and the others, however despicable their actions, only did what many of us would have done if placed in the same situation, which puts their guilt in a questionable light. Can someone be guilty just for acting like most ordinary human beings?

In a famous experiment back in the 1970s, Philip Zimbardo and other psychologists at Stanford University put college students into a prison-like setting in the basement of the psychology department. Some of the students played prisoners and others guards, with uniforms, numbers, reflecting sunglasses and so on. The psychologists’ aim was to strip away the students’ individuality and see what the situation might produce on its own.

What happened was truly disconcerting — the guards grew increasingly abusive, and within 36 hours the first prisoner had an emotional breakdown, crying and screaming. The researchers had to stop the experiment after six days. Even normal kids who were professed pacifists were acting sadistically, taking pleasure in inflicting cruel punishments on people they knew to be completely blameless.

These were ordinary American college kids. They weren’t monsters, but began acting monstrously because of the situation they were in. What happened was more about social pattern, and its influence, than about the character of individuals.

Emeritus professor at Stanford, Zimbardo has argued in a recent book, “The Lucifer Effect,” that what happened in these experiments is also what happened at Abu Ghraib. As he points out, in lots of the photos the soldiers weren’t wearing their uniforms; they were anonymous guards who referred to the prisoners with dehumanizing labels such as “detainees” or “terrorists.” There was confusion about responsibility and little supervision of the prison at night.

The more the soldiers mistreated the prisoners, the more they saw them as less than human and even more worthy of that abuse. In both the experiments and at Abu Ghraib, most of the abuse took place on the night shift. In both cases, guards stripped prisoners naked to humiliate them and put bags over their heads. In both cases, the abuse involved the forced simulation of sexual behavior among the prisoners.

Frederick hooked up wires to hooded detainees, made them stand on boxes and told them they’d be electrocuted if they fell off. He stomped on prisoners hands and feet. He and others lined up prisoners against the wall, bags on their heads, and forced them to masturbate. His actions were indeed monstrous.

But when Zimbardo, as an expert witness, interviewed Frederick during his court-martial, these were his impressions:

He seemed very much to be a normal young American. His psych assessments revealed no sign of any pathology, no sadistic tendencies, and all his psych assessment scores are in the normal range, as is his intelligence. He had been a prison guard at a small minimal security prison where he performed for many years without incident. … there is nothing in his background, temperament, or disposition that could have been a facilitating factor for the abuses he committed at the Abu Ghraib Prison.

If someone chooses to commit an illegal act, freely, of their own will, then they are plainly guilty. Conversely, the same act performed by someone acting without free will, compromised by mental illness, perhaps, or the coercion of others, draws no blame. Far less clear is the proper moral attitude toward people who do illegal things in situations where the social context exerts powerful, though perhaps not completely irresistible, forces.

Can a person be guilty of a crime if almost everyone, except for a few heroic types, would have done the same thing? This is a question for legal theorists, and one likely to arise ever more frequently as modern psychology reveals just how much of our activity is determined not consciously, through free choice, but by forces in the social environment.

But the more immediate question is why those who set up the conditions that led to Abu Ghraib, or at least made it likely, haven’t also been held responsible. When Frederick arrived at Abu Ghraib, abusive practices, authorized from above, were already commonplace. Prisoners were being stripped, kept hooded and deprived of sleep, put in painful positions and threatened with dogs. On his first day there, Frederick recalled, he saw detainees “naked, handcuffed to their door, some wearing female underclothes.”

The conditions cited by Zimbardo, the situational recipe for moral disaster, were already in place.

The conclusion isn’t that Frederick and the others didn’t do anything wrong, or that they somehow had an excuse for their actions. They could and should have acted better, and Frederick has admitted his own guilt. “I was wrong about what I did,” he told the military judge, “and I shouldn’t have done it. I knew it was wrong at the time because I knew it was a form of abuse.”

But you and I cannot look at Frederick and the other guards as moral monsters, because none of us can know that we’d have acted differently. The evidence suggests that most of us wouldn’t have. The coercion of the social context was too powerful.

The second conclusion is that those really responsible for the abuse, on a deeper and more systematic level, still should be brought to justice. They’re in the upper tiers of the military chain of command and its civilian leadership; they’re in the White House.

Today, Frederick will wake up in prison, have his breakfast, take some exercise and face the daily monotony of prison life, something he can expect for the next 1300 days or so. He can be justifiably angry that those responsible for putting him in that setting at Abu Ghraib, where almost anyone would have done the same thing, are today walking around free.

The key ideas

Anyone coming to this site for the first time may have no idea what The Social Atom is about, or what are the key notions of social physics. Here are a few of the key ideas:

First point: We need to think in terms of patterns, not people. Social science has not progressed primarily because of an excessive fixation on the complexity of individuals, whereas it is collective patterns of order and organization that are often most important.

For example, imagine a crowd on the street, maybe people shopping at Christmas time, or flooding out of a stadium after a big football game. Everyone goes more or less where they want to go, and the chaos of the crowd reflects a mass of different individual decisions. There doesn't seem to be any order or organization. But in fact if you look closely you'll see something interesting - that many people move through the crowd within fairly narrow streams or lanes in which everyone moves in the same direction and flows along with one another. These streams snake through the crowd, form and dissolve, and they tend to persist. Why? Because people find that moving within these lanes or streams, flowing along with their neighbors, is generally easier than fighting with the chaos of the rest of the crowd. Even if a stream takes you a little off course, its better to move with it and then backtrack.

The interesting thing is that no one intends or plans these patterns, yet they end up really having a lot to do with how people move through the crowd. This is the idea of pattern, not people. To understand the flow of people in a crowd, just thinking about atomized individuals and their intentions isn't nearly enough - you have to take account of these patterns.

Now, this is a trivial example and not really important. But modern research is finding that similar patterns influence our lives at many levels - in the way we think, the opinions we have and the clothes we wear, our political beliefs, what we do for a living and so on. Although we tend to think of ourselves as self-determined individuals making up our own minds, we're strongly affected and influenced by what others around us do and we get carried forward in persisting streams of behavior, not unlike those streams in a crowd. These streams lie behind everything from fashions to runs in the stock market to the way we form social classes or have certain values. Without intending to, we help create youth movements, waves of hysteria, religious cults or nationalistic fervor, and these then act as forces that constrain and channel our own behavior. Yet we don't often see this, and as a result we miss the really important forces that influence our lives. To understand the human world better, we need to think of patterns, not just people.

Point two: This perspective actually has quite a lot in common with physics, with key problems that physicists face and the way they go about solving them. Physics is largely about understanding the laws of collective pattern and organization.

Most people think physics is quantum theory, Albert Einstein and relativity, the atom bomb, black holes and so on. This is the popular image of physics, and this is physics, but a lot of modern physics has also gone off in another direction, and most people don't know this. Consequently, there is a great misunderstanding about whether physics can help us understand the human world. People say that can't be possible, because you can't wrap up human life in simple equations, but what they're thinking about is physics as it was two centuries ago, when the whole idea was about finding the fundamental equations. Physics has moved way beyond that, and to see how physics can help, you need to have an updated view of what it is.

Most physicists today actually work on the physics of ordinary stuff such as liquids and solids. Water is a liquid when it comes out of the tap; put it into the freezer and it turns to solid ice. What makes that happen? What happens when water boils and turns to vapor? Ultimately, it is all down to the way the atoms fit together; the patterns by which they fall together in the substance. Take the very same atoms and put them together differently and you get completely new things. Diamond, which is made of carbon atoms, becomes the soft graphite of a pencil tip. You get a new and totally different material just by putting the same atoms together in a different pattern. The key insight in this field that almost all of the properties of a substance - its being a liquid or solid, whether it is soft or hard, elastic or brittle, its color - all have to do with how the atoms or molecules inside are put together. A lot of modern physics is really concerned with understanding how this can be; how organization can emerge on its own, the laws by which it forms, and so on. The answers don't always come down to simple equations, but this science has done a lot to understand how simple processes can give rise on their own to organized forms of surprisingly complexity.

Scientists are beginning to see that much the same is true when you look at the social world. Much more than their individual personalities, what is most important is the patterns of how people interact. Just as you can study the atoms in a diamond in infinite detail and never answer why it is diamond and not graphite, you'd never understand the social world even if you knew everything about individual people. So in a sense, physics and social science really face much the same problem - trying to understand how relatively simple parts get put together to create wholes, collective systems with properties all their own.

Our understanding of the human world is still relatively backward, I think, in part because the philosophy of man and society got off on the wrong track centuries ago and has been stuck with some damaging preconceptions, the worst of which is that man is somehow essentially different from the rest of nature and stands apart from it. This idea is still very influential. Even so, there's been lots of recent work by psychologists showing that individual people often follow fairly simple rules in making decisions. There are universal characteristics that hold across cultures. In every place on earth you find families, you find social norms, you find a few rich and many poor, you find fashions, waves of irrational behavior, religion and so on. These are the social equivalents of things like liquids and solids, only we're not used to thinking of them this way. We'll get more used to it in the future.

Point three: These ideas have real repercussions, as a few visionary thinkers have known for many years.

As one example, take racial segregation. In the US you have whites in suburbs, blacks in inner cities, a long-standing, very important problem. The cause, most people automatically think, is racism. But you have to think a little more carefully. Scientists have actually known for decades that you can have segregation even without racism - that quite innocent human behavior, nothing remotely linked to racism, can make the races separate more or less like oil and water.

Here's why. For the sake of argument, just suppose that everyone would like to live in a nice 50-50 mixed community. But that also no one really wants to be part of an extreme minority of less than, say, 30%. This isn't really being racist. Yet look what happens. If you start out with people mixed together randomly, you will find, just by pure chance, that some neighborhoods tend to be mostly white and others mostly black. Indeed, by chance alone, you'll find that a few people do end up living in neighborhoods where they're part of an extreme minority. Suppose these people move out to a more balanced area. Then the neighborhood they leave behind becomes even more strongly segregated, in turn driving out others. It's a simple mathematical process. In this way, scientists have shown, you can get pronounced racial segregation, pushing whites and blacks into separate enclaves, even if everyone really preferred to be mixed together. It's very surprising and counterintuitive, but true. This is the power of pattern over people. You can easily get an outcome that absolutely no one desires or intended.

Now, to be absolutely clear, this isn't to say there isn't racism. There are racists and their attitudes and actions cause lots of damage, but the point is that racial segregation might not have much to do with racism, which can actually have a much simpler mechanical cause. The point is that you certainly need to know about this if you hope to do anything about it.

Point four: Patterns can also be positive. By learning how to manage them, we could be more effective in making intelligent social policies.

For example, consider the amazing turn around of population growth in Kerala, the southern-most state of India. Until about 15 years ago, population was exploding there as it is in the rest of India, and nothing seemed to work. The government even tried a program of forced sterilization, which also failed. Then something almost miraculous happened. In the late 1980s, the Keralan government - aided by volunteer organizations - undertook a massive effort to stamp out illiteracy in Kerala. Literally tens of thousands of volunteers crisscrossed the countryside and managed to track down over 150,000 illiterates, of whom two-thirds were women. Three years later, in 1991, the United Nations declared Kerala the world's only 100% literate state - and surprisingly, the population then stopped growing. Today Kerala has the same birthrate as European nations. This region of India solved this age-old problem not by addressing re-production directly, but through simple education, especially of women.

Now it's interesting to see how this worked. There are two keys. The first is that education empowers women to seek other interests outside the home, in employment or otherwise. They gain power and have more control over their reproductive lives. You'd expect this to have some effect on population growth, but a second effect - a pattern effect - seems to explain why change came to Kerala so quickly and why it has been a stable change. No person lives in isolation, unaffected by the actions of others. For centuries, Keralans lived simple agricultural lives without need to advanced education. It's easy for parents to decide not to push for education for their children when education isn't likely to be important in their lives. But when lots of people become educated everything changes. When everyone else is educated, and when life comes to depend on education, then what was formerly an understandable decision to forego education now becomes obviously unattractive to everyone. Education itself becomes self-sustaining, not because people have changed as individuals, not because of human psychology, but because of the logic of collective patterns and what supports them. This seems to be a general lesson - that education creates self-sustaining streams of good consequences.

There are also positive streams carrying us forward over much longer timescales. This seems to be the best explanation, for example, for our human ability to be kind to others even in situations when we get nothing directly back in return. No other organism on Earth does this, and there's a real biological mystery here, as evolution is not generally kind to those who do not consider their own needs first. But the deep explanation seems to be that selfless behavior probably helped our ancestors survive within strong and cohesive groups. We tend to forget that more than 99% of human history was history utterly unlike what we know today. Our ancestors lived as hunter-gatherers in small groups in the jungles and on the plains, and they often had deadly combat with others, or had to compete with others for land. It is not too hard to imagine that if two groups were competing, one being made of completely selfish individuals, and the other of ready cooperators, the latter would have a big advantage. Many of us today have altruistic feelings because such feelings have been essential to the successful history of human groups - so you could say that even individual human character bears the traces of collective, pattern effects.

So the patterns I'm talking about aren't necessarily positive or negative, but can be either.

Point five: There is no contradiction between individual freedom and the existence mathematical laws for the human world much like those of physics. The idea that there is rests on a deep misunderstanding.

Birth rates have gradually fallen all across the Western world over the past 40 years. There's a general trend you find in every country - the US, Germany, Spain. This obviously doesn't imply that any particular set of parents didn't make choices and express their freedom. Patterns can exist at the level of many people, even while individuals continue being free, there's just no contradiction in that.

Think about the end of a music concert. You can begin clapping early or late, clap for a long or short time, expressing your individual attitude. But if you make recordings of clapping - and scientists have actually done this - you find that the way the sound rises and falls tends to follow a universal mathematical pattern, much like clockwork. What's even more surprising is that the very same pattern shows up in the way groups of people change from one kind of behavior to another - the way many people across the globe have adopted cell phones over the last few decades, for example. You cannot understand these trends accurately if you think that everyone made up their minds independently. Rather, as in the case of clapping, lots of people are strongly influenced by what they see others around them doing. The pattern acts back to influence and channel individual actions. So while were free, we're also strongly influenced and channeled by social patterns.

To take another example, consider the stock market. An investor might be the smartest person in the world, and know for sure that stock in IBM or some other company should begin rising rapidly tomorrow. But if for some completely crazy reason everyone begins selling IBM, and its price plummets, that wisdom doesn't count for much - hanging on against the herd may come at a terrific price. Again, the things we do are often strongly constrained by what the group does, and as a result, human behavior is often far more predictable than you might think.

Point six: Doing social physics has become much easier with modern computers. Computational capacity explains why this revolution is happening now.

For centuries the great philosophers and social theorists have played around with fascinating games of "what if." Plato explored what the supposed perfect state would be if it was ruled by wise Philosopher- Kings. More recently we've had spectacular - and often spectacularly painful - musings on the benefits of anything from communism to deregulation. Unfortunately, these musings have always been based around lots of vague words and arguments, because no human mind is smart enough to foresee what really might happen when you make changes in systems involving ten or a hundred or a million people. The growing web of causes and effects just overwhelms the power of even the greatest human mind to foresee what might come out.

But no more - or at least not always. Today, scientists have learned to augment the power of their minds with computing technology. The idea is to build models of social systems - a community, a company, a market, etc. You program lots of computer agents to act like people, to make decisions like people do, to learn and adapt, and then you run the computer to see what comes out - the computer does all the hard work, and very quickly. In this way you can carry out "virtual" social experiments to find answers to "what if" questions, something that has only become possible in the past few years. For example, you can look at the way companies grow. Companies form because people working together can do a lot more than people working on their own. Everyone knows that. What you find in these experiments, however, is a much deeper story about how companies evolve over time - they tend to start out with lots of hard workers, but over time, as they get bigger, tend to get infected with free riders - people who like the big salary but don't actually work so hard, and put more effort into appearing to work hard. This makes older companies vulnerable, and leads to a natural life cycle of the firm. A surprising conclusion is that companies don't persist just by making profits. They persist by having an ability to attract and keep good workers.

This kind of thing is really being used. Several years ago the NASDAQ stock exchange planned to change the tick size - the basic price increment - of its securities listings, thinking that a smaller size would make it easier for the market to discover the price of stocks more accurately. It sounded like an obviously good idea, but the exchange wisely decided to investigate further before going ahead. They developed a model of their exchange based around adaptive computer agents who were able to adapt and alter their trading strategies on the fly, or discover new strategies, just like real people. Then they used the model as a laboratory, and found that reducing the tick size beyond a certain point actually made things worse as some agents were able to exploit weaknesses to cheat the market and make easy profits. These strategies grew less risky and more profitable with a smaller tick size. Fortunately, NASDAQ discovered this before learning the same lesson in reality. These kinds of models are now being used all over the place.

Red Think/Blue Think

Explain this. A recent poll taken by the Pew Research Center asked Americans to give one word best describing their impression of George Bush. The ten most common responses appear to reveal extreme partisan polarization, with half strongly positive and half strongly negative. While the two most popular responses were "incompetent" and "arrogant," the next two were "honest" and "good," followed by "idiot," "integrity," "leader," "strong," "stupid" and "ignorant." Nothing middle of the range there. You either like and respect Dubya, or you view him with utter contempt.

I've often wondered how this can be. Clearly all people aren't forming their views by a lengthy and thorough consideration of the facts, because then most would have similar views. A better explanation, perhaps, may lie in research that suggests that something in the way our brains work makes us highly susceptible to strongly partisan views, because they help to preserve our emotional link to some group with which we have become associated (the political left or right, for example). The force is so deep that many people do not even perceive evidence that contradicts their pre-formed opinions.

For example, in the run up to the 2004 U.S. presidential election between George Bush and John Kerry, researchers led by psychologist Drew Westen of Emory University had partisan Republicans and Democrats look at quotes, from Bush or Kerry, in which the candidates were clearly contradicting themselves. Westen and colleagues monitored the brain activity in these individuals as they tried to explain the contradictions. They found no increased activity in parts of the brain normally engaged during reasoning. Rather, it was primarily brain circuits involved in emotion and conflict resolution that lit up. As Westen concluded, "None of the circuits involved in conscious reasoning were particularly engaged... Essentially, it appears as if partisans twirl the cognitive kaleidoscope until they get the conclusions they want...”.

In other words, many of us seem to filter reality in an emotional way so as to preserve and support groups to which we feel linked. Any understanding of politics, I think, of the vast division between Red and Blue states, for example, has to take this into account. It's the strong influence of these emotional blinders that makes the political talk shows so clearly ridiculous as a means for finding anything like consensus or deeper understanding. In these shows, quite literally, all are talking while none are hearing.