First days at Dartmouth College

I just arrived in Hanover, NH to start a new position at Dartmouth College. I earned a fellowship from the Neukom Institute for Computational Science. William Neukom is Bill Gates’ old lawyer, and he was an alumnus of the College, and it seems he wanted to give back by funding interdisciplinary research that involves computers. For the next few years, he’s funding mine.

The town is very pretty. Also tiny: ten times smaller than Bloomington, IN, the previous smallest town I’ve lived in. But there’s plenty here for me, and plenty of goodness. Something tells me that, despite the deep deep isolated winter, life will be easier here than it was in Switzerland. I’ve already started mapping the local fruit trees, many of which are in action now. I found hops, which I’d never actually seen before, but which I recognized from beer bottles. Lots of micro brews use hops flowers as a motif to ornament the labels of their brews. Ha! The flower looks more like the bud of a flower than like a lower itself. If you grab it and mash it up in your fingers it smells delicious. It might actually be edible, though not every part of the flower is as palatable as others. And I’ve had another unexpected find for this latitude. I was walking along an ivy-covered wall, or at least I assumed it was ivy, and found it was grape-vine-covered instead. And I found another bunch of grapes vines later that day. All way under-ripe, but I’ll be paying attention as the season passes. I’ll be totally surprised, and utterly pleased, if edible grapes grow around here in the fall time.


This entry was posted on Tuesday, September 1st, 2015 and is filed under updates.

Extra info about my appearance on BBC Radio 4

I was on a BBC radio documentary by Jolyon Jenkins, “Rock Paper Scissors.” The goal of the documentary was to show that this seemingly trivial game is secretly fascinating, because of what we humans make of it. My own academic contribution to that fun claim has been published here and in much more detail here.

Jolyon was a gracious host, but the documentary was released without any word or warning to me, and with rough spots. I’ve got to clarify a few things.

The most important is an error. The show ended with my describing a game in which people “irrationally” herd together and make lots of money. The results of this game were reported faithfully in the show, but the game itself got defined wrong, and in a way that makes the results impossible. Here’s the full game: All of you pick an integer 1 through X. Each person gets a buck for picking a number exactly one more than what someone else picked. ADDITIONALLY, the number 1 is defined to be exactly one more than number X, making the choices into a big circle of numbers. The documentary left that last bit out, and it’s really important. Without anything to beat X, I’m guessing that everyone will converge pretty quickly on X without much of this flocking behavior. It’s only when the game is like Rock Paper Scissors, with no single choice that can’t be beat by another, that you start to see the strange behavior I describe in the show.

Three more things. All of the work was done with my coauthor and advisor Rob Goldstone at IU, who wasn’t mentioned. Second, it’s not accurate, and pretty important, the way that Jolyon implicitly linked my past work to my current employer. The work presented on the show was performed before I started with Disney Research, and has nothing to do with my work for Disney Research. Last, a lot of what I said on the show was informed by the work of Colin Camerer, specifically things like this.


This entry was posted on Wednesday, August 5th, 2015 and is filed under audio/visual, updates.

Paper on Go experts in Journal of Behavioral and Experimental Economics

I just published a paper with Sascha Baghestanian​ on expert Go players.

Journal of Behavioral and Experimental Economics

It turns out that having a higher professional Go ranking correlates negatively with cooperation — but being better at logic puzzles correlates positively. This challenges the common wisdom that interactive decisions (game theory) and individual decisions (decision theory) invoke the same kind of personal-utility-maximizing reasoning. By our evidence, only the first one tries to maximize utility through backstabbing. Go figure!

This paper only took three years and four rejections to publish. Sascha got the data by crashing an international Go competition and signing up a bunch of champs for testing.


This entry was posted on Saturday, July 25th, 2015 and is filed under science, updates.

Unplanned downtime last week

The site was down because I got hacked — didn’t keep wordpress up to date. The site is still affected, with slow load times. The good news was that someone told me about the problem, a sure sign that people actually read this blog. Go Figure.


This entry was posted on Thursday, July 16th, 2015 and is filed under updates.

My dissertation

In August I earned a doctorate in cognitive science and informatics. My dissertation focused on the role of higher-level reasoning in stable behavior. In experimental economics, researchers treat human “what you think I think you think I think” reasoning as an implementation of a theoretical mechanism that should cause groups of humans to behave consistently with a theory called Nash equilibrium. But there are also cases when human higher-level reasoning causes deviations from equilibrium that are larger than if there had been no higher-level reasoning at all. My dissertation explored those cases. Here is a video.

My dissertation. The work was supported by Indiana University, NSF/IGERT, NSF/EAPSI, JSPS, and NASA/INSGC.

Life is now completely different.


This entry was posted on Monday, November 25th, 2013 and is filed under books, science, updates.

Enfascination 2013

29742_396066756605_704462_n“Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.” Thus spoke Martin Luther King Jr. in a great endorsement for humility, curiosity, and discovery.

On Thinko de Mayo, from 1PM, you will have five minutes to help us see how dangerous we are. You may share anything at all during your five minutes, as long as you personally think it’s fascinating. Your goal is to transmit your sense of fascination to others. FB page:

If the constraints of themes help you brainstorm, try “Science towards nescience.” But generally, you should trust yourself. If you manage nothing more than five minutes of wobbling, inarticulate, ecstatic blubbering then Well Done: You have successfully expressed the unfathomable depth of your subject.

This is the ten-year anniversary of these lectures –– ten years since I attempted the world’s nerdiest 21st birthday kegger. This will be the fifth and probably last in Bloomington. Ask me for help if you’ll have slides or a demo.

Past topics have included:
Slide Rules, Counting the Permutations of Digit Strings, Conceptions of Time in History, Chili Peppers, How to cross a glacier, The Singularity, Indiana Jones, Rural desert water distribution systems, Hexaflexagons, Small precious things, Wilderness Camps as Commodity, DIY Cooking, Roman Emperor Deaths , Joy of Science, Salt , Three Great Banquets in Italian History, How to Sharpen a Chisel, Some Properties of Numbers in Base Ten, The Physiological Limits to Human Perception of Time, Geophagy, Pond Ecology, Superstition: For Fun and Profit, Counterintuitive Results in Hydrodynamics, The Wolof Conception of Time, Arctic String Figures, The Seven Axioms of Mathematics, Dr Seuss and his Impact on Contemporary Children’s Literature, Twee, Motorcycle Life and Culture, Cultural Differences Between Japan and the US, Brief history of the Jim Henson Company, Female Orgasm, Insider Trading: For Fun and Profit, Film of Peter Greenaway, A Typographical Incident with Implications for the Structure of Thought, Cooperative Birth Control, Tones in Mandarin, Unschooling and Deschooling, Q&A: Fine Beer, DIY Backpacking, Chinese Nationalism in Tibet, Biofuels, The Yeti, The Health Benefits of Squatting, The Big Bang, How to Pick Stocks Like a Pro, Food Preservation Technique, or Managing Rot, Infant Visual Perception, Demonstrations in Number Theory, Rangolis, Kolum, The Hollow Earth, Edible Mushrooms: For Fun and Profit, Human Asexuality, A History of the California Central Valley Watershed, An Account of the Maidu Creation, The Paleoclimatology of the Levant, Rural India, German Compound Words, Manipulating Children, Physics of Time, Animal Training on Humans, Constructed Languages, This Week’s Weather, The XYZs of Body Language, Light Filtration Through Orchards, Our Limits in Visualizing High Dimensional Spaces,Twin Studies.

Last year’s audio:
And video/notes from before that:


UPDATE post-party

Here is what happened:

  1. The Tiger Café by Ronak
  2. Jr. High School Poetry Slam by Lauren
  3. The “Border” language by Destin
  4. Perception/Objectivity by Paul Patton
  5. Readings from James Agee by Jillian
  6. “A signal detection theory of morality” or “The morality manatee” by Seth
  7. Dreams and the four candies by Danny
  8. Pick Two by Adam
  9. Trust and Trust Experiments by Jonathan

Rock-Paper-Scissors ms. on Smithsonian, NBC, and Science Daily blogs.

This is my first (inter)national press, I’m a little embarrassed to feel excited about it. Its also a pleasant surprise, I wouldn’t have expected it to have general appeal.


Enfascination 2012 number 2 at the Complex Systems Summer School in Santa Fe, NM

I spent the summer of 2012 with fascinating people. Seeing only their talent as scientists, I thought I knew how fascinating they were. But this short-notice series of short talks revealed their depth. There is no record of the proceedings, only the program:

SFI CSSS Enfascination, for we must stop at nothing to start at everything:
Priya on Symmetries
Kyle on the adversarial paradigm
Drew on the history of espionage in Santa FE
Tom’s song, the Power Law Blues
Seth on keiteki rio
“Yeats on robots sailing to Byzantium” by Chloe
Christa and her Feet
Xin on Disasters
“Kasparo, A robotics opera” by Katrien
Jasmeen on post-war polish poetry
Keith on voting
Madeleine’s “Paradoxes of modern agriculture”
Sandro singing “El Piscatore”
Robert on audio illusions, specifically Shephard tones and the McGurk effect
Isaac on biblical Isaac
Miguel on the diversity of an unpronounceably beautiful variety of sea creature
Nick on mechanical turk
Georg’s poetry

Come Fall 2013, I’m working for Disney Research in Zurich

They don’t currently do social science, but they’ve gotten a taste of what it can do and where it can go. They’ve hired me to help launch an interdisciplinary behavioral research agenda — economics, sociology, psychology — lab experiments, web experiments, simulations, and big data. I don’t know what to expect, but I believe its in line with my goals for myself and I’m excited and grateful.


This entry was posted on Thursday, February 21st, 2013 and is filed under science, updates.

In PLOS ONE: Cyclic dynamics driven by iterated reasoning

This paper, published with my advisor Rob Goldstone, reports a major result of my dissertation, that people can flock not only physically, but also in their depth of iterated reasoning through each other’s motives. It is interesting because of the many economists who hoped that type of reasoning would prevent flocking. Ha!

* Here is the paper:
which follows the preprint

* One-minute video of this emergent cyclical behavior:

* Three-minute video explaining it in terms of the movie The Princess Bride:

* And here is a press release draft to give you a sense of it:

Rock-Paper-Scissors reveals herd behavior in logical reasoning

“Poor Bart, always picks Rock.” In these telling words from Lisa Simpson, we see Rock-Paper-Scissors as a game of mind reading. Scientists have already used Rock-Paper-Scissors to study how we cooperate, to show that we are bad randomizers, and to build AIs that can beat us at our own game. But this simple game has many more tricks up its sleeve. Rock-Paper-Scissors gives us the ideal case study for herd behavior in higher-level reasoning: specifically, thoughts about the thoughts of others. You would like to think that your thoughts are your own, but recent work from the Indiana University Cognitive Science program shows that people playing Rock-Paper-Scissors subtly influence each other, converging on similar ways of reasoning over time. The natural analogy is to a flock of birds veering in concert.

In work appearing in PLoS ONE (XXX), Seth Frey and Robert L. Goldstone introduce a version of Rock-Paper-Scissors called the Mod Game. In each round, they gave IU psychology undergraduates a choice between the numbers 1 through 24. Participants earned money for picking a number exactly one greater than someone else, but the choices wrapped around in a circle so that 1 beat 24 (just as Ace beats King in card games). Participants just had to anticipate what others were going to pick, and pick the next number up — keeping in mind that everyone else was thinking the same thing. In this game of one-upmanship, the best performers aren’t the ones who think the most steps ahead, but the ones who think just the right number of steps ahead — about two, as it turned out in the experiment.

Many economists predict that with enough experience, people should be able to think infinite steps ahead, or at least that their number of steps should increase dramatically over time. But this isn’t what happened in the Mod Game. Instead, when participants were shown each previous round’s results, they tended to cluster in one part of the circle of choices and start bounding around it in synch. Groups produced a compelling periodic orbit around the choices, reminiscent of the cultural pendulum swinging back and forth, bringing, say, moustaches in and out of fashion. Interestingly, the cycling behavior consistently got faster with time. This means that people did learn to think further ahead with time — the economic prediction was partly correct — but the increase was much less dramatic than it ought to have been: after 200 rounds of the Mod Game, the average number of thinking steps increased by only half a step, from 2 to 2.5. Moreover, herding in this game benefited everyone; a tighter grouping of choices means a higher density of money to be earned in each round.

What does all this mean for society? Typical treatments of higher-level reasoning look to it as preventing herd behavior, but we can now see it as a source. Anticipation may be the motor that keeps fads running in circles. It could be a source of the violent swings that we see in financial markets. And if you’ve ever been in a bidding war on Ebay, you may have been caught in this dynamic yourself. If every bidder is tweaking their increasing bids based on the tweaks of others, then the whole group may converge in price and in how those prices rise. The process isn’t governed by the intrinsic value of that mint Star Wars lunch box you’re fighting for, but on the collective dynamics of people trying to reason through each other’s thoughts. Whether looking at benign social habits or mass panics, social theorists have always treated human herd behavior as though it resulted from mindlessness. But this simple lesson from Rock-Paper-Scissors suggests that even the most sophisticated reasoning processes may be drawn about by the subtle influence of social interaction.