A Beginner’s Guide: Special Projects

Some assignments in “A Beginner’s Guide to Irrational Behavior” were graded, but many were not. We were delighted to see an incredible amount of effort put into all of the projects in this course, and some amazing products have emerged. Below, we’ve collected just a few of them to share.

Multimedia Project

For this project, students were asked to pick one theme from the course and put their creative skills to work, depicting that topic through art. They could produce a video exploring conflicts of interest, record a song about the strength of social norms, create a graphic novel dealing with the stress of high bonuses, paint a painting that reflects decision making in a state of arousal, write a poem about the what-the-hell effect, design an app that helps people save for retirement, make an elementary school lesson plan to teach kids about defaults, and so on — anything was on the table.


Increasing pain of payment by Anna Pasquale


An Animated Definition of Irrationality by Jean Synodinos

Irrationality: From A to Z by Geeta Sadashivan


April Fools’ Meme by Paul Fenwick



Irrational Chicken by James Coombes (with illustrations by Geeta Sadashivan)


Song: Predictably Irrational by Jan Zurcher

Listen to it here: https://soundcloud.com/jan-zurcher-1/predictably-irrational/s-ZeNwH


Predictably Irrational
Reason will propel me
Into the traps and snares
Professed by Dan Ariely
Invited to Dan’s for dinner
I should take a gift
Just a little something
To give his day a lift
Perhaps a box of candy
Would really fit the bill
I’ll try that little candy store
Up on the hill


The shelves are filled with bon-bons
Three hundred different kinds
So many varied choices
It’s boggling to the mind
My brain’s about to pop
I turn to walk away
Just then I notice
The “Special of the Day”


I pull money from my pocket
“Pain of paying” hits me hard
Maybe ‘stead of cash
I should use my credit card
As I stand there waiting
I run a mental account
My monthly gifting budget
Won’t cover this amount


What happens if I steal it?
People do that all the time
But “Do unto others”
Reads the little sign
I know – I’ll make some
Use my grandma’s recipe
It’ll be the best
‘Cause it’s made by me


I’ve made an extra batch
I’ll just try a little bite
Before I know it
I’ve eaten everything in sight



Micro-story: “Just One Breath” by Douglas Gunn

Author’s note: in the following micro-story, Just One Breath, I’m trying to evoke the feeling state of that special moment, an example of cognitive dissonance, when we identify irrationality in another person but willfully decide to ignore their behaviour, in effect becoming complicit with their irrationality, because we feel sympathy or compassion for the person. We consciously decide that dispelling their irrational belief comes with a higher cost than leaving the person to continue with their belief.

There’s this guy on Queen Street,
missing an ear
and an eye that looks over everybody’s shoulder,
the other glancing at the legs of the Pretty Ladies.
One Ear smells like the back seat of a late night cab
and he sucks hard at a soundless harmonica,
cursing blue-onions, and other impossibilities, each time he runs out of breath.
“What’cha doin’, man?” I say, twirling a quarter in my pocket.
One Ear looks up – simultaneously at me and somewhere into the heavens above my shoulder – and says “Gettin’ rich.”
“Is that right?” I let the quarter slip from between my fingers to nestle deep in my pocket once again. “How’s that work, exactly?”
“What’s it to you?”
“Just curious,” I’m all sincere and marvel as One Ear looks like he might yet, for a moment, manage to focus both eyes on me.
“Just between you and me?” mumbles One Ear.
“There ain’t no one else listenin’”
“Guy came by last week, says to me, all jovial like, ‘I like your sound. You want a million dollars?’”
“And you said?”
“’Who don’t?’”
And I think there’s no arguing with tautology. “He’s paying you to play that thing?”
“No, man.” One Ear’s all indignant and getting up in my face. “I gotta work at it some.”
“Then you get your million bucks?”
“You daffy?” One Ear sends both eyes staring off over my shoulders each in search of different astrological signs. “Gotta master it first, Ol’ Man River.”
“Ol’ Man River? For a million dollars?”
“There’s a twist.”
“Is that right?” I try not to sound dubious.
“In one breath.”
“Just one?”
“Tha’s right.”
“Ol’ Man River on the harmonica in a single breath?”
“uh-hu” One Ear nods, pursing his lips to give another go at the instrument in his hands.
“You get your money then, huh?”
“Any chance this guy ain’t bein’ sincere?”
“What’cha sayin’?”
“Well, maybe he doesn’t think he’ll ever have to pay you.”
“He said he heard about one of them Sherpa’s, high in the mountains, that could do it.”
“I don’t know about that…”
“‘Coz you ain’t rich.”
“And this guy was?”
“He had a nice suit on.”
“That certainly says something about a man”
“And shiny shoes. One’s I could see my face in.”
“Gotta trust a man who shows you your own face.” I listened for a few moments to One Ear draining his lungs of oxygen, depleting the harmonica of dulcet tones, and searched my pocket for errant change. “Look,” I say, and wait patiently for One Ear to look. “How  ‘bout I give you a quarter to play part of Long Tall Sally?”
“No way”
“Gotta keep practicin’. Guy said I won’t get no money if I play anything else.”
“That’s what he said, eh?”
“Uh-hu. And you just gotta believe a man dressed like that.”
“I suppose you do,” I say and toss my quarter into the overturned hat lying on the sidewalk next to One Ear.

A Beginner’s Limerick to Irrational Behaviour by René Kragh Pedersen

A professor at Duke once confessed
How a coworker’s candy did test
He started out light,
then his morals took flight:
“What the hell – I’ll eat all the rest!”
Affective forecasting they say,
is a situational sway
a predictional predicament
on adaptions ambivalent
Will I like Minnesota in May?
A flea market hoarder so proud
With collections that garnered a crowd
Was offered in gold,
Yet nothing got sold
The effect? He was too well endowed!
There once was a boss quite impressed,
with researchers of brainwork the best
When she meant to inspire
A large bonus proved dire
They got so motivated they stressed!
A quick motivation from Sue,
on office relations kung fu
when you fail to acknowledge
the work of your colleagues
It hurts like you tore it in two!

Mastering Irrationality? by Anna Rooney

I read it in the paper,
then I heard it on the news.
I thought about it, talked about it,
gathered several  views.
I Googled it, considered it
and checked my bank account.
Did I really need to buy it?
An astronomical amount!
Come on now, I started thinking,
Try not to be a fool.
Please do not be irrational
What did they teach you in that school?
Could I get a second-hand one?
Maybe Craigslist – maybe borrow.
Was that really worth the effort?
Maybe wait until tomorrow.
I had a fleeting thought just then
that my birthday is in May.
Should I put it on my wish list?
That way someone else would pay.
As I walked and thought and pondered
I noticed a window display
And there it was, before my eyes
it was my lucky day.
It was on sale, the right colour
and they only had one there.
But was I being rational?
I didn’t really care.
So then and there, I rushed right in
And bought it – ignore the plan!
I deserve a little treat, n’est ce pas?
And to my teacher…..sorry, Dan

Professor Dan and his students by Sheryl Wickwire

Here’s to Professor Dan Ariely
Who talked about choosing jam, not jelly
Learning from his Center for Advanced Hindsight
His students spend many a late night
Reading instead of watching the telly

Social Norms & Market Norms Don’t Mix by Sheryl Wickwire

Arriving at the party with a gift
Norm unintentionally created a rift
When he announced what it cost
The evening was lost
Leaving the hostess quite miffed.


A Birthday Card for Dan (from the class)


Course Wiki

The course wiki will remain open to coursera students, even after the course site closes. This is an editable document, full of relevant resources and guides to further explore the content of the class.

Student Stories

We asked students to share their stories, and tell us whether they decided to make changes to their professional or personal lives as a result of this class, and what happened as a result of those changes. Below are just a few of their stories:

I want to thank Dr. Ariely, Aline Gruneisen, and the rest of the team for a truly amazing course. Since I teach part-time at a local college and have done online courses on occasion, I am aware of the tremendous amount of work and thought that has gone into this course. I wish you had a Wishlist or “Tip Jar” somewhere or, at the very least, I could buy you all a beverage of your choice. I would be more than happy to make a donation in your names to a favorite charity, if you’d like. 

Had behavioral economics been around when I was in college, I would have instantly changed my major. Instead, we were telling this joke:
A physicist, an architect, and an economist were stranded on a desert island. The physicist and architect had managed to construct a rudimentary shelter and cistern to hold fresh water, but there wasn’t much food until a cargo box of canned beans floated onshore. Unfortunately, there was no way to open the cans. The physicist suggested heating a can over a fire until the pressure caused the can to burst. The economist, who had done nothing but sit under a palm tree and stare at the ocean since they washed ashore, pointed out the beans would be lost in the sand. So the architect suggested they construct a container to catch the beans. The economist found a flaw with every design and every plan the physicist and architect came up with to open the can. Finally, in frustration, the architect shouted, “Well, if your so smart, why don’t you solve the problem?” The economist said, “It’s simple. First, you assume a can opener.”

And for those non-classic economist, the joke was popular because whenever a problem came up in economics, the usual response was “First, we assume…” 

Thank you all for showing me that I wasn’t crazy when I argued that people did not behave according to the classical economic models. And, Dr. Ariely, thank you for all the great jokes! I’ll keep an eye out on Coursera for any future classes from any of the team members or guest lecturers. Oh, and i’ve been driving people nuts telling them about this class and the related books and materials.

Carolyn E. Cooper

Thank you Dan and your hard working team!!! This had been the best course I have ever taken! I found it interesting and fun. I must admit that I went into this course thinking I was going to be a sponge and the course would be easy. Boy was I wrong! And I am glad that I was so wrong. The course required so much more from me than I expected and pushed me in ways that, quite frankly, surprised me. I found myself putting aside reading time and study time every week. I never expected to be apart of the discussion forum and yet week after week I found myself on the forums and immersed in the fascinating topics. I learned things that I know will change the way I think and act for the rest of my life. What a profound effect your course has had on me. I grumbled about the readings but felt immense pride and joy when I finished each week’s reading. The difficulty of the class made me appreciate all of the effort that I put into. I would recommend this course to anyone. Thanks once again for such a wonderful experience!!

Vanessa De Guglielmo

My three year old kid has demonstrated to be more “sophisticated” than his mother by consciously choosing one marshmallow now instead of experiencing the frustration of failing to wait for the other one (he nibbled the first one in a previous attempt)… I wonder if this shows he is more aware of his limits than many of us… I will follow up with praise, encouragement, humor and training, and later on perhaps making the reward more tempting (my son is not much of a sweet tooth), or asking someone more neutral to try it with him in a more controlled environment. Perhaps at some point he will tell me he is ready for the challenge to wait.

My life feels at times like living in a sociological experiment: like a person from a foreign planet trying to communicate and interact, observing and recording what is going on around me. A couple of years ago, just entering my thirties, I was diagnosed what was formerly called Asperger, now it is defined being highly functional somewhere in “the autism spectrum.” I think the best description would be having two left brains… The feeling is of an excessive “rationality” in some areas of my life, where a part of the naive conclusions of traditional economics are going on in my head naturally as defaults when making a decision or evaluating a situation. Meanwhile, I was puzzled to observe people many times behaving in ways that were counterintuitive for me, and at the same time I was puzzling those around me. I notice I was able to perceive and point out incongruities and dissonances, as well as marketing tricks and conflicts of interest that were not so evident to others. Cognitive overload is also a big part of my life, and inability to detect deception explains many of the free falls I have experienced, along with a lack of a tightly knit social support network. Frankly, there is no fudge factor for me for enacting dishonesty, it seems it is just not build into my system, and can’t help myself. Don’t get me wrong, I am human alright and visceral factors get to me, as well as the IKEA effect, perception of fairness and effort, decision illusions and many more…

Thanks to this course I have found many explanations, which are helping me greatly to improve my empathy (towards myself and others), decision and social networking skills. Of special value were the lectures on social and market norms, and how it affects social interaction and contracts. Very useful indeed was the lecture of uniting the decision and the consumption environments, yes, you guessed it, almost all my purchases, even celery, tend to be rationally assessed and don’t work when opening the fridge hungry for instance. In this sense I am also learning from my kid to let go just a little, and am enjoying my purchases more. 

The part about humor was also very useful in order to understand it better, but I will limit benign violations to myself or hypothetical others, because I feel the boundaries can be easy to cross.

I have been fascinated with the effect of honor codes, where this moral reminder can cancel cheating, I even proposed them as an intervention for the pernicious not invented here bias but I agree they have to be varied so as not to create numbing. By the way, the paper on psychic numbing is probably the best I have read in my life, I have passed it on to any heavy weights in my contact list.

Living in a very poor country and not being completely solvent myself, I was also particularly touched by the effects of being poor and how it highlights trade offs and pain of paying which can lead to cognitive overload and bad financial decisions (like borrowing at insane rates).

One of my hobbies is religious studies, and this course has spurred a lengthy reflection on the connections between the topics of the course and some religious principles**.

As an underemployed free lance consultant and single mother (where’s my second marshmallow?*** ???? the tradeoffs to balance work, sleep and a demanding toddler in order to be fully engaged in the course have been salient at times, but well worth it.

I feel awareness and overcoming default attitudes and behaviors are key aspects to this course, like in that “This is water” speech that is going around****…

Thank you for helping me rationalize the irrational, and enjoy and appreciate it more. This is quite the journey.

Yasmina N. Mata

As a piano teacher, I have been faced every year with the dilemma of how to get my students to agree to participate in the recital at the end of the school year. Of course, most students view the recital with a sense of dread, and fear that they will get nervous playing in front of an audience rather than just me, and that that anxiety will cause them to “blow it.” While all of the parents also share that concern, some tell their child that they will participate, and other parents ask their child if they want to participate. I have never really liked when the parents ask their kids if they want to do it, because, for the most part, they will say that they don’t. I feel that the parents who take this approach are afraid of their child having a bad experience and are unwilling to let them take that risk. Getting the child properly prepared to take on that risk involves a lot of work on my part, as the teacher, and extra work on the part of the parents. They will have to make sure that their child gets in the necessary practice time, which could also mean dealing with resistance. I think letting their kid make the choice is subconsciously the easier option for the parents.

In past years, I have sent emails to the parents announcing the date of the recital, explaining that the recital is optional, and that they should let me know as soon as possible if their child was going to be participating. The number of students who ended up playing at the recitals would be around two-thirds of my total number of students, and sometimes it was slightly more than half.

This year, through what I have learned in this class, I realized that I had been using the “opt in” option as my default. Therefore, the emails that I sent to the parents this year were very different. I announced the date of the recital. I told them that the recital was appropriate for even the most beginning of piano students. I told them that I would be assigning recital pieces to the students during the next couple of weeks, and that they were free to contact me with any questions. I used the “opt out” default. It worked. All but two of my students agreed to participate this year. 

Dan, this class has been wonderful! I am sure that I have bored people talking about it and posting on Facebook. You have a way of making your students feel like you are a friend, even via computer. I always couldn’t wait for the new lectures to be posted. I particularly enjoyed the Office Hours. What I liked most about your jokes was that I could tell that you liked them. So, even though I had heard them multiple times (rewatching the lectures), I would still laugh out loud when you delivered the punchline. There was a twinkle in your eye, and that cracked me up…

Doreen Leigh

Dear Prof. Ariely and your team, It might sound clichéd, but the fact is that taking your course was one of the most enjoyable things I have done in recent years. I am a former insurance industry worker turned stay-at-home mom, who discovered and fell in love with behavioral psychology/economics. I am a voracious reader of the subject and a follower of your column at WSJ. Your course was the most intellectually stimulating experience for me, and last night when I found out I had made a perfect score of 62, I sat staring at it in disbelief with tears in my eyes. Recently with my youngest child turning 6, I had been thinking of going back to school, but couldn’t decide what to study. I think I have found the answer! Every week I looked forward to hearing your lectures, and getting started on the “required reading.” I plan to read the “recommended” list gradually, since it was hard to find the time during the course. I involved my entire family in the course, and I think they enjoyed it alongside me, particularly my husband who tends to be fairly evolved and ‘rational,” and my 12 year- old son who is not. Now we are missing the excitement and I am hoping that you will consider an Advanced course soon!! Thank you!

Maneesha Sharma

…I have learned so much from this course that I will apply to my ethics work with companies. Codes of Ethics are a necessary part of ethics programmes, but as you found at Princeton they may not be very effective. The course has given me some ideas about how to use them differently. The “signing before” rather than “signing after” aspect of integrity commitments will also come in handy. And many others.

In my own life, I struggle with eating a bit too much and rationalising it in various ways. I already realised that I had to have the commitment to the personal trainer to counteract my tendency not to go to the gym, despite actually enjoying exercise.

I always looked forward to Tuesdays when new lectures would be posted and found myself carving out the necessary time to listen to all of them once on Tuesday or at least by Wednesday. I would also listen to them again throughout the week. I started the course thinking that I wouldn’t necessarily do the quizzes or the exam, or the writing assignment. By the beginning of week 2 I realised that I would do EVERYTHING and was looking forward to it. I have spent the last month 3,000 miles away from where I live finishing the process of emptying out my parent’s home and selling it. There was much to do, but having the lectures to watch and other things related to the course helped me feel not so alone and to give me something else I considered worthwhile to do. I was concerned that I would have to take the Final Exam with jet lag after my return to London yesterday; however I broke it in half and did only half on no sleep and the rest today after a long night’s sleep. So, one can always find the time for something that is important!

My favourite Dan quote is when you have good ideas and lawyers in the same room it means NO ACTION. I hope that despite being a lawyer by profession although no longer by practice, I have gotten many good ideas and that I WILL TAKE ACTION in my ethics work to implement these ideas.

I really felt for Dan when he mentioned his experiences talking to bankers, etc. I talk to senior executives of companies regularly and the extent to which their biases and other irrationalities determine the destiny of their companies and employees is appalling. I would only encourage Dan and his colleagues NOT TO GIVE UP. It only takes one powerful and strategically placed person in the management team to see the wisdom sometimes for an idea to be adopted.

 Thank you very much Dan and the entire team. You have created a quality course – don’t dumb it down next time – and better yet, do “An Advanced Guide to Irrationality” instead so I can continue the journey with you.

Ruth Steinholtz

I can not express how much I enjoyed this course. Apart from all interesting insights in human behavior, it also meant a big deal for me in terms of self esteem. I have met many difficulties in my education because I am disorganized, easily distracted and have lack of self control. Recently I quit an important and expensive education because I could not get to the content of the course. I lost my way in practical information, schedules, complicated websites etc. It costed me 2000 euro and I left with nothing than a feeling of disappointment. As soon as I was on my feet again I became curious and interested in learning again. This is the paradox I often meet in my life. At that moment I found this course. It is my first MOOC experience. Now Dan, I know you are not happy with offering these courses for the price of FREE but if I had to pay I would not dare to take this course because I did not trust myself anymore. I found it so inspirational to listen to your lectures, I even loved your very cheesy jokes. The content of this course was a feast of recognition. I discussed the content with my friends and colleagues. Reading the academic papers was hard for me. I have to admit that I expanded my fudge factor a little bit and sometimes just read the beginning and the end. The real challenge for me was the writing assignment. I am happy I did not give up. I also liked the community very much. It is very inspirational to “meet” people from all over the world studying the same subject. The only thing I did not like was the negative response about the grades and the statement of accomplishment. People have the right to express their opinion, of course, but I was annoyed by all the whining. Maybe because I had the experience of being treated really fairly and positively by the people who graded my essay. This course made me follow more coursera courses. They are also very interesting but this one is still the best. Thank you so much for this positive experience.

Connie van Pinxteren

I am finding this course immediately practical. I am a medical director of an ICU here in central Indiana, and at a single multidisciplinary critical care meeting yesterday I found 3 opportunities for behavioral economics to impact meaningful change:

1. Switching to an “opt-out” default order to help cardiologists comply with a newly implemented policy not to mix heparin into arterial line bags (a decades-old practice that is now understood to carry risk.)

2. Using an “identifiable victim” approach to help deal with a problem of ICU nurses occasionally not calling the Organ Bank when certain patients are reaching the end of life. (This is a call they know they are supposed to make according to established policy, but at times is inconvenient. The “victim” becomes the unseen potential organ recipient, who loses that opportunity when a potential donor dies without the family being asked about donation.)

3. Using short term “reward substitution” to help us through a culture change of using less sedation in the ICU. Use of less sedation is the newer standard of practice that is associated with better outcomes, but is initially hard on the staff because they have to handle agitation differently and more frequently at first.

I do believe that these tools are the wave of the future in developing better ways to provide ICU care and to help prevent faulty decision making by providers.

Thank you Dan and your Lab (by the way, I would love to contribute to your lab by buying a few of your CAH teeshirts… I’m sure I’m not the only one!) for your devoted attention to this course. I think that my vision of the world is forever changed, and I look forward to learning more about this subject and implementing where I can.

David Ryon

For the Writing Assignment, I wrote about a way to solve the problem of unpicked fruit in our valley, here in Soller, Mallorca, Balearic Is., Spain. This morning I discovered in the local paper that two charities have devised a way to use my idea! (which they must have picked up on the virtual ether telepathic waves, unless they’re also part of this MOOC and one of them was an evaluator of my W.A. ???? They have managed to persuade some of the farmers to let unemployed people pick the oranges, with the benefits going to the pickers and the farmers are ‘Feeling Good About Giving’ (Anik, Aknin, Norton & Dunn, 2009) and avoiding loss aversion by not spending money to have the fruit picked.

Grace Helen Mayer