Social Contagion Modeled on Random Networks

 

Check out the video of Daniel Cicala’s talk, the fourth in the Applied Category Theory Seminar here at U. C. Riverside. It was nicely edited by Paola Fernandez and uploaded by Joe Moeller.

Abstract. A social contagion may manifest as a cultural trend, a spreading opinion or idea or belief. In this talk, we explore a simple model of social contagion on a random network. We also look at the effect that network connectivity, edge distribution, and heterogeneity has on the diffusion of a contagion.

The talk slides are here.

Reading material:

• Mason A. Porter and James P. Gleeson, Dynamical systems on networks: a tutorial.

• Duncan J. Watts, A simple model of global cascades on random networks.

Cognition, Convexity, and Category Theory

Two more students in the Applied Category Theory 2018 school wrote a blog article about a paper they read:

• Tai-Danae Bradley and Brad Theilman, Cognition, convexity and category theory, The n-Category Café, 10 March 2018.

Tai-Danae Bradley is a mathematics PhD student at the CUNY Graduate Center and well-known math blogger. Brad Theilman is a grad student in neuroscience at the Gentner Lab at U. C. San Diego. I was happy to get to know both of them when the school met in Leiden.

In their blog article, they explain this paper:

• Joe Bolt, Bob Coecke, Fabrizio Genovese, Martha Lewis, Dan Marsden, and Robin Piedeleu, Interacting conceptual spaces I.

Fans of convex sets will enjoy this!

Liars and Hypocrites

Who do you trust: the liar or the hypocrite?

Some people like to accuse those are worried about climate change of being “hypocrites”. Why? Because we still fly around in planes, drive cars and so on.

What’s the argument? Could it be this?

“If even those folks who claim there’s a problem aren’t willing to do anything about it, it must not really be a problem.”

That argument is invalid. Say we have a married couple who both smoke. The husband says “we should quit smoking.” But he keeps smoking. Does this mean that it’s okay to smoke?

Or suppose he says “you should quit smoking”, but keeps on smoking himself. That’s would be infuriating. But it doesn’t make the statement less true.

Indeed, our civilization is addicted to burning carbon. It’s a lot like being addicted to nicotine. Addiction leads people to say one thing and do another. You know you should change your behavior—but you don’t have the will power. Or you do for a while… but then you lapse.

I see this in myself. I try to stop taking airplane flights, but like most successful scientists I get lots of invitations to conferences, with free flights to fun places. It’s hard to resist. It’s like offering cigarettes to someone who is trying to quit. I can resist nine times and cave in on the tenth! I can “relapse” for months and then come to my senses.

In fact the accusation of hypocrisy is not about the facts of climate change. It’s about choosing a social group:

“The people who want you to take climate change seriously are hypocrites. Don’t be a sucker. Don’t let them boss you around. Join us instead.”

This takes advantage of a psychological fact: most of us prefer liars to hypocrites. A lie is forgivable. But hypocrisy—someone publicly saying you should do something when they don’t themselves—is not.

There are studies about this:

• Association for Psychological Science, We dislike hypocrites because they deceive us, 30 January 2017.

The title of this article is wrong. Liars also deceive us. We hate hypocrites for other reasons.

We’re averse to hypocrites because their disavowal of bad behavior sends a false signal, misleading us into thinking they’re virtuous when they’re not, according to new findings in Psychological Science, a journal of the Association for Psychological Science. The research shows that people dislike hypocrites more than those who openly admit to engaging in a behavior that they disapprove of.

“People dislike hypocrites because they unfairly use condemnation to gain reputational benefits and appear virtuous at the expense of those who they are condemning–when these reputational benefits are in fact undeserved,” explains psychological scientist Jillian Jordan of Yale University, first author on the research.

Intuitively, it seems that we might dislike hypocrites because their word is inconsistent with their behavior, because they lack the self-control to behave according to their own morals, or because they deliberately engage in behaviors that they know to be morally wrong. All of these explanations seem plausible, but the new findings suggest that it’s the misrepresentation of their moral character that really raises our ire.

In an online study with 619 participants, Jordan and Yale colleagues Roseanna Sommers, Paul Bloom, and David G. Rand presented each participant with four scenarios about characters engaging in possible moral transgressions: a member of a track team using performance-enhancing drugs, a student cheating on a take-home chemistry exam, an employee failing to meet a deadline on a team project, and a member of a hiking club who engaged in infidelity.

In each scenario, participants read about a conversation involving moral condemnation of a transgression. The researchers varied whether the condemnation came from a “target character” (who subjects would later evaluate) or somebody else, as well as whether the scenario provided direct information about the target character’s own moral behavior. Participants then evaluated how trustworthy and likeable the target character was, as well as the likelihood that the target character would engage in the transgression.

The results showed that participants viewed the target more positively when he or she condemned the bad behavior in the scenario, but only when they had no information about how the character actually behaved. This suggests that we tend to interpret condemnation as a signal of moral behavior in the absence of direct information.

A second online study showed that condemning bad behavior conveyed a greater reputational boost for the character than directly stating that he or she didn’t engage in the behavior.

“Condemnation can act as a stronger signal of one’s own moral goodness than a direct statement of moral behavior,” the researchers write.

And additional data suggest that people dislike hypocrites even more than they dislike liars. In a third online study, participants had a lower opinion of a character who illegally downloaded music when he or she condemned the behavior than when he or she directly denied engaging in it.

I believe the accusation of hypocrisy is trying to set up a binary choice:

“Whose side are you on? Those hypocrites who say climate change is a problem and try to get you to make sacrifices, while they don’t? Or us liars, who say there’s no problem and your behavior is fine?”

Of course, being liars, they leave out the word “liars”.

One way out is to realize it’s not a binary choice.

There’s a third position: the honest hypocrite.

Perhaps the most critical piece of evidence for the theory of hypocrisy as false signaling is that people disliked hypocrites more than so-called “honest hypocrites.” In a fourth online study, the researchers tested perceptions of “honest hypocrites,” who—like traditional hypocrites—condemn behaviors that they engage in, but who also admit that they sometimes commit those behaviors.

“The extent to which people forgive honest hypocrites was striking to us,” says Jordan. “These honest hypocrites are seen as no worse than people who commit the same transgressions but keep their mouths shut and refrain from judging others for doing the same — suggesting that the entirety of our dislike for hypocrites can be attributed to the fact that they falsely signal their virtue.”

There’s also a fourth position: the non-liar, non-hypocrite. That’s even better. But sometimes, when we need to take collective action, we should listen to the honest hypocrite, who tells us that we should all take action, but admits he’s not doing it yet.

And now, here’s a great example of someone trying take advantage of our hatred of hypocrites. Pay careful attention to how she cleverly tries to manipulate you! By the end you’ll feel different than when you started. If she were trying to get you to smoke, by the end you’d light up a cigarette and feel proud of yourself.

An example

The Hypocrisy of Climate Change Advocates
Julie Kelly

So according to all the hysterical people, President-elect Donald Trump has appointed the most climate denier cabinet ever. As cabinet confirmation hearings get underway, expect to hear the charge “climate denier!” a lot.

For those of you who don’t know what a climate denier is, it means you either challenge, question or flat-out reject the idea that the planet is warming due to human activity. In the scientific world and in the world of international liberal groupthink (but I repeat myself), this is blasphemy. Should you remotely doubt the dubious models, unrealized dire predictions, changing goal posts or flawed data related to climate science, you are not just stupid according to these folks, but you are on par with those who deny the Holocaust.

Even people who believe in manmade climate change (or AGW, anthropogenic global warming) have been excommunicated from the climate tribe for raising any concern about climate science. Last month, Roger Pielke, Jr. wrote a revealing op-ed in the Wall Street Journal about how he became a target of the climate junta for saying there was no connection between weather disasters and climate change. Although Pielke believes in AGW and even supports a carbon tax to mitigate its impact, his scrutiny made him a target of powerful folks in Congress, the media and even the White House.

The first time I was called a climate denier was a few years ago, after I started writing about agricultural biotechnology or GMOs. The charge was an attempt to undermine my credibility on supporting genetic engineering: the line of attack was, if you don’t believe the science and consensus about man-made global warming, you are a scientific illiterate who has no business speaking in defense of other scientific issues like biotechnology. This was often dished out by climate change pushers who also oppose GMOs because they are anti-capitalist, anti-corporate ideologues (Bernie Sanders could be the poster child for this).

As I did more research on climate change, I learned one important thing: being a climate change believer means never having to say you’re sorry, or at least never making any major sacrifice to your lifestyle that would mitigate the pending doom you are so preoccupied with (but, sea ice!). You can go along with climate change dogma and do virtually nothing about it except recycle your newspapers while self-righteously calling the other side names. From the Pope to the president to the smug suburban mom, climate adherents live in glass houses that function thanks to evil stuff like oil and gas while throwing rocks at us so-called deniers.

So who are the real deniers: those who are reasonably skeptical about climate change or those who give lots of lip service to it while living a lifestyle totally inimical to every tenet of the climate change creed?

To that end, you might be a climate change denier if:

You are the Holy Father of the largest denomination of the Christian faith who calls climate change “one of the principal challenges facing humanity in our day” and that coal, oil and gas must be replaced “without delay” yet lives a palatial lifestyle powered by fossil fuels.

You are the president of the United States who tried to ban fracking on public land because it emits greenhouse gases but then takes credit for cutting “dependence on foreign oil by more than half” thanks to fracking.

You are a presidential candidate whose primary message is blasting big corporations from Exxon to Monsanto for destroying the planet but then demands a private jet to make meaningless campaign appearances on behalf of the woman who beat you so you can keep getting attention for yourself.

You are a movie star who works in one of the most energy-intensive and frivolous industries but now earns fame by leading protests against fracking and demands the country live on 100 percent renewables by 2050 then jets your family off from Manhattan to Australia on a jumbo jet to take pictures of the Great Barrier Reef.

You are Robert Kennedy, Jr.

You drive a Tesla but don’t know the electricity comes from a grid supported by fossil fuels.

You are a legislator who pushes solar panels and wind turbines without having the slightest clue how much energy and materials — like steel, concrete, diesel fuel, fiberglass and plastic — are needed to manufacture them.

You are Leonardo DiCaprio.

You are a suburban mom who looks down at other moms who don’t care/know/believe in climate change but you spend the day driving your privileged kids around in a pricy SUV and have two air-conditioners in your 6,000 square-foot house,

You oppose nuclear energy and/or genetically engineered crops.

You eat meat because meat production allegedly emits about 14.5 percent of greenhouse gases or some made-up number according to the United Nations.

You eat any sort of food because agriculture uses all kinds of climate polluting energy not to mention the big carbon footprint to process, package, ship and deliver that food to your local Whole Foods.

You are John Kerry.

So if you live off the grid, never fly in an airplane and don’t eat, then you can call me a denier. For the rest of you, please zip it. You deny climate change by your actions because you contribute daily to the very greenhouse gases you contend are destroying the planet. I’d rather be a denier than a hypocrite any day.

Complexity Theory and Evolution in Economics

This book looks interesting:

• David S. Wilson and Alan Kirman, editors, Complexity and Evolution: Toward a New Synthesis for Economics, MIT Press, Cambridge Mass., 2016.

You can get some chapters for free here. I’ve only looked carefully at this one:

• Joshua M. Epstein and Julia Chelen, Advancing Agent_Zero.

Agent_Zero is a simple toy model of an agent that’s not the idealized rational actor often studied in economics: rather, it has emotional, deliberative, and social modules which interact with each other to make decisions. Epstein and Chelen simulate collections of such agents and see what they do:

Abstract. Agent_Zero is a mathematical and computational individual that can generate important, but insufficiently understood, social dynamics from the bottom up. First published by Epstein (2013), this new theoretical entity possesses emotional, deliberative, and social modules, each grounded in contemporary neuroscience. Agent_Zero’s observable behavior results from the interaction of these internal modules. When multiple Agent_Zeros interact with one another, a wide range of important, even disturbing, collective dynamics emerge. These dynamics are not straightforwardly generated using the canonical rational actor which has dominated mathematical social science since the 1940s. Following a concise exposition of the Agent_Zero model, this chapter offers a range of fertile research directions, including the use of realistic geographies and population levels, the exploration of new internal modules and new interactions among them, the development of formal axioms for modular agents, empirical testing, the replication of historical episodes, and practical applications. These may all serve to advance the Agent_Zero research program.

It sounds like a fun and productive project as long as one keeps ones wits about one. It’s hard to draw conclusions about human behavior from such simplified agents. One can argue about this, and of course economists will. But regardless of this, one can draw conclusions about which kinds of simplified agents will engage in which kinds of collective behavior under which conditions.

Basically, one can start mapping out a small simple corner of the huge ‘phase space’ of possible societies. And that’s bound to lead to interesting new ideas that one wouldn’t get from either 1) empirical research on human and animal societies or 2) pure theoretical pondering without the help of simulations.

Here’s an article whose title, at least, takes a vastly more sanguine attitude toward benefits of such work:

• Kate Douglas, Orthodox economics is broken: how evolution, ecology, and collective behavior can help us avoid catastrophe, Evonomics, 22 July 2016.

I’ll quote just a bit:

For simplicity’s sake, orthodox economics assumes that Homo economicus, when making a fundamental decision such as whether to buy or sell something, has access to all relevant information. And because our made-up economic cousins are so rational and self-interested, when the price of an asset is too high, say, they wouldn’t buy—so the price falls. This leads to the notion that economies self-organise into an equilibrium state, where supply and demand are equal.

Real humans—be they Wall Street traders or customers in Walmart—don’t always have accurate information to hand, nor do they act rationally. And they certainly don’t act in isolation. We learn from each other, and what we value, buy and invest in is strongly influenced by our beliefs and cultural norms, which themselves change over time and space.

“Many preferences are dynamic, especially as individuals move between groups, and completely new preferences may arise through the mixing of peoples as they create new identities,” says anthropologist Adrian Bell at the University of Utah in Salt Lake City. “Economists need to take cultural evolution more seriously,” he says, because it would help them understand who or what drives shifts in behaviour.

Using a mathematical model of price fluctuations, for example, Bell has shown that prestige bias—our tendency to copy successful or prestigious individuals—influences pricing and investor behaviour in a way that creates or exacerbates market bubbles.

We also adapt our decisions according to the situation, which in turn changes the situations faced by others, and so on. The stability or otherwise of financial markets, for instance, depends to a great extent on traders, whose strategies vary according to what they expect to be most profitable at any one time. “The economy should be considered as a complex adaptive system in which the agents constantly react to, influence and are influenced by the other individuals in the economy,” says Kirman.

This is where biologists might help. Some researchers are used to exploring the nature and functions of complex interactions between networks of individuals as part of their attempts to understand swarms of locusts, termite colonies or entire ecosystems. Their work has provided insights into how information spreads within groups and how that influences consensus decision-making, says Iain Couzin from the Max Planck Institute for Ornithology in Konstanz, Germany—insights that could potentially improve our understanding of financial markets.

Take the popular notion of the “wisdom of the crowd”—the belief that large groups of people can make smart decisions even when poorly informed, because individual errors of judgement based on imperfect information tend to cancel out. In orthodox economics, the wisdom of the crowd helps to determine the prices of assets and ensure that markets function efficiently. “This is often misplaced,” says Couzin, who studies collective behaviour in animals from locusts to fish and baboons.

By creating a computer model based on how these animals make consensus decisions, Couzin and his colleagues showed last year that the wisdom of the crowd works only under certain conditions—and that contrary to popular belief, small groups with access to many sources of information tend to make the best decisions.

That’s because the individual decisions that make up the consensus are based on two types of environmental cue: those to which the entire group are exposed—known as high-correlation cues—and those that only some individuals see, or low-correlation cues. Couzin found that in larger groups, the information known by all members drowns out that which only a few individuals noticed. So if the widely known information is unreliable, larger groups make poor decisions. Smaller groups, on the other hand, still make good decisions because they rely on a greater diversity of information.

So when it comes to organising large businesses or financial institutions, “we need to think about leaders, hierarchies and who has what information”, says Couzin. Decision-making structures based on groups of between eight and 12 individuals, rather than larger boards of directors, might prevent over-reliance on highly correlated information, which can compromise collective intelligence. Operating in a series of smaller groups may help prevent decision-makers from indulging their natural tendency to follow the pack, says Kirman.

Taking into account such effects requires economists to abandon one-size-fits-all mathematical formulae in favour of “agent-based” modelling—computer programs that give virtual economic agents differing characteristics that in turn determine interactions. That’s easier said than done: just like economists, biologists usually model relatively simple agents with simple rules of interaction. How do you model a human?

It’s a nut we’re beginning to crack. One attendee at the forum was Joshua Epstein, director of the Center for Advanced Modelling at Johns Hopkins University in Baltimore, Maryland. He and his colleagues have come up with Agent_Zero, an open-source software template for a more human-like actor influenced by emotion, reason and social pressures. Collections of Agent_Zeros think, feel and deliberate. They have more human-like relationships with other agents and groups, and their interactions lead to social conflict, violence and financial panic. Agent_Zero offers economists a way to explore a range of scenarios and see which best matches what is going on in the real world. This kind of sophistication means they could potentially create scenarios approaching the complexity of real life.

Orthodox economics likes to portray economies as stately ships proceeding forwards on an even keel, occasionally buffeted by unforeseen storms. Kirman prefers a different metaphor, one borrowed from biology: economies are like slime moulds, collections of single-celled organisms that move as a single body, constantly reorganising themselves to slide in directions that are neither understood nor necessarily desired by their component parts.

For Kirman, viewing economies as complex adaptive systems might help us understand how they evolve over time—and perhaps even suggest ways to make them more robust and adaptable. He’s not alone. Drawing analogies between financial and biological networks, the Bank of England’s research chief Andrew Haldane and University of Oxford ecologist Robert May have together argued that we should be less concerned with the robustness of individual banks than the contagious effects of one bank’s problems on others to which it is connected. Approaches like this might help markets to avoid failures that come from within the system itself, Kirman says.

To put this view of macroeconomics into practice, however, might mean making it more like weather forecasting, which has improved its accuracy by feeding enormous amounts of real-time data into computer simulation models that are tested against each other. That’s not going to be easy.

 

Information Aversion

 

Why do ostriches stick their heads under the sand when they’re scared?

They don’t. So why do people say they do? A Roman named Pliny the Elder might be partially to blame. He wrote that ostriches “imagine, when they have thrust their head and neck into a bush, that the whole of their body is concealed.”

That would be silly—birds aren’t that dumb. But people will actually pay to avoid learning unpleasant facts. It seems irrational to avoid information that could be useful. But people do it. It’s called information aversion.

Here’s a new experiment on information aversion:

In order to gauge how information aversion affects health care, one group of researchers decided to look at how college students react to being tested for a sexually transmitted disease.

That’s a subject a lot of students worry about, according to Josh Tasoff, an economist at Claremont Graduate University who led the study along with Ananda Ganguly, an associate professor of accounting at Claremont McKenna College.

The students were told they could get tested for the herpes simplex virus. It’s a common disease that spreads via contact. And it has two forms: HSV1 and HSV2.

The type 1 herpes virus produces cold sores. It’s unpleasant, but not as unpleasant as type 2, which targets the genitals. Ganguly says the college students were given information — graphic information — that made it clear which kind of HSV was worse.

“There were pictures of male and female genitalia with HSV2, guaranteed to kind of make them really not want to have the disease,” Ganguly says.

Once the students understood what herpes does, they were told a blood test could find out if they had either form of the virus.

Now, in previous studies on information aversion it wasn’t always clear why people declined information. So Tasoff and Ganguly designed the experiment to eliminate every extraneous reason someone might decline to get information.

First, they wanted to make sure that students weren’t declining the test because they didn’t want to have their blood drawn. Ganguly came up with a way to fix that: All of the students would have to get their blood drawn. If a student chose not to get tested, “we would draw 10 cc of their blood and in front of them have them pour it down the sink,” Ganguly says.

The researchers also assured the students that if they elected to get the blood tested for HSV1 and HSV2, they would receive the results confidentially.

And to make triply sure that volunteers who said they didn’t want the test were declining it to avoid the information, the researchers added one final catch. Those who didn’t want to know if they had a sexually transmitted disease had to pay $10 to not have their blood tested.

So what did the students choose? Quite a few declined a test.

And while only 5 percent avoided the HSV1 test, three times as many avoided testing for the nastier form of herpes.

For those who didn’t want to know, the most common explanation was that they felt the results might cause them unnecessary stress or anxiety.

Let’s try extrapolating from this. Global warming is pretty scary. What would people do to avoid learning more about it? You can’t exactly pay scientists to not tell you about it. But you can do lots of other things: not listen to them, pay people to contradict what they’re saying, and so on. And guess what? People do all these things.

So, don’t expect that scaring people about global warming will make them take action. If a problem seems scary and hard to solve, many people will just avoid thinking about it.

Maybe a better approach is to tell people things they can do about global warming. Even if these things aren’t big enough to solve the problem, they can keep people engaged.

There’s a tricky issue here. I don’t want people to think turning off the lights when they leave the room is enough to stop global warming. That’s a dangerous form of complacency. But it’s even worse if they decide global warming is such a big problem that there’s no point in doing anything about it.

There are also lots of subtleties worth exploring in further studies. What, exactly, are the situations where people seek to avoid unpleasant information? What are the situations where they will accept it? This is something we need to know.

The quote is from here:

• Shankar Vedantham, Why we think ignorance Is bliss, even when It hurts our health, Morning Edition, National Public Radio, 28 July 2014.

Here’s the actual study:

• Ananda Ganguly and Joshua Tasoff, Fantasy and dread: the demand for information and the consumption utility of the future.

Abstract. Understanding the properties of intrinsic information preference is important for predicting behavior in many domains including finance and health. We present evidence that intrinsic demand for information about the future is increasing in expected future consumption utility. In the first experiment subjects may resolve a lottery now or later. The information is useless for decision making but the larger the reward, the more likely subjects are to pay to resolve the lottery early. In the second experiment subjects may pay to avoid being tested for HSV-1 and the more highly feared HSV-2. Subjects are three times more likely to avoid testing for HSV-2, suggesting that more aversive outcomes lead to more information avoidance. We also find that intrinsic information demand is negatively correlated with positive affect and ambiguity aversion.

Here’s an attempt by economists to explain information aversion:

• Marianne Andries and Valentin Haddad, Information aversion, 27 February 2014.

Abstract. We propose a theory of inattention solely based on preferences, absent any cognitive limitations and external costs of acquiring information. Under disappointment aversion, information decisions and risk attitude are intertwined, and agents are intrinsically information averse. We illustrate this link between attitude towards risk and information in a standard portfolio problem, in which agents balance the costs, endogenous in our framework, and benefits of information. We show agents never choose to receive information continuously in a diffusive environment: they optimally acquire information at infrequent intervals only. We highlight a novel channel through which the optimal frequency of information acquisition decreases when risk increases, consistent with empirical evidence. Our framework accommodates a broad range of applications, suggesting our approach can explain many observed features of decision under uncertainty.

The photo, probably fake, is from here.

To Really Judge Good Music, Turn Off the Sound

In a study published in the Proceedings of the National Academy of Sciences, Chia-Jung Tsay showed musicians clips from classical music competitions. She asked them to guess the winners. Different musicians were given different kinds of clips: audio recordings… videos with sound… and videos with no sound!

They did best when they saw videos with no sound.

It’s not that the winners were good-looking. It’s that they moved in expressive ways.

This reminds me of how people are willing to pay more for wines whose names are hard to pronounce… or how you can predict who will win an election by watching videos of the candidates—with the sound off.

I think there’s something important about these results. They’re a bit depressing: if our cognitive apparatus is so deeply flawed, maybe we’re doomed. But maybe it’s not so bad. Maybe we just tend to define the point of various activities too narrowly!

We go to a concert, not just to listen to music, but to watch the performer. We drink a wine, not just to taste it in our mouth, but to bask in the sense of being sophisticated. We judge a candidate, not just by what they say, but by how they say it.

You can see the paper here:

• Chia-Jung Tsay, Sight over sound in the judgment of music performance, Proceedings of the National Academy of Sciences, 19 August 2013.

You can hear (or see) a nice summary and discussion here:

• Shankar Vedantam, How to win that music competition? Send a video, National Public Radio, 20 August 2013.