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The Power of a Nudge—Part 2: Little Nudges with Big Impact

Lithium Alumni (Retired) Lithium Alumni (Retired)
Lithium Alumni (Retired)

Last time, we took a theoretical exploration of a nudge—a subtle intervention that slightly changes the context (i.e. the environment, the presentation, etc.) to drive certain behaviors. This allowed us to understand its relationship with respect to other techniques that drive behaviors. Like the baby-step approach, nudge also focuses on the ability factor of the Fogg’s Behavior Model (FBM). However, the difference between nudge and baby step is that nudge focuses on simplifying the context while baby step focuses on simplifying the behavior itself.


Nudge in the right direction.pngBecause simplicity is a stronger behavior driver than motivation (which is commonly used in gamification), nudge is very powerful! Cognitive psychology and behavioral economics have demonstrated again and again that small and apparently insignificant contextual changes can have a major effect on people's behavior. Today, I will present several famous examples of how small changes of context can nudge people’s behavior significantly. I will also dive deeper to understand the real power of a nudge.


Default This and That

One of the most popular and powerful tools for nudging people’s behavior is the use of defaults. It is fairly well know that a pre-selected or presumed default choice can increase a selection significantly. Nations that require citizens to explicitly opt-out of organ donation have a significantly higher—more than 3x—organ-donor rate than nations that require citizens to explicitly opt-in. Simply changing the presentation of the choices—a seemingly insignificant change of context—has a huge effect on what people ultimately choose.


There are several reasons why defaults have such a strong effect on behavior. First, defaults change the perception of the social norm, because people may believe that default choice is the one picked by most others. So people simply choose the default due to social conformity. The second reason is that people may perceive the default as a recommended choice that is somehow optimal. Lastly, defaults change the perception of the status quo. When a choice is complex or far in the future, such as organ donation, people don’t immediately grasp the consequences of their choice. In this scenario, people tend to stay with the status quo, because that is the path of least effort. 

Nudge Organ Donation Default2 px600.png

Yes, you guessed it; defaults are little nudges with huge impact.


Environmental Changes to the Path of Least Resistance

Another powerful tool for nudging people into the habit of doing something is to change the environment. Simply by placing salads and fruits at eye-level on shelves, that are easy to reach in a cafeteria (and placing the sweets on harder to reach shelves) can nudge people into the habit of heathier diet. This is a very subtle change of the environment that doesn’t forbid people from eating sweets or changing their incentives for picking sweets over salads, or vice versa. The consumers always have a choice to pick the less healthy alternative should they want to. However, this subtle change of the environment is able to increase salad consumption by 300% and increase fruit sales by 102%.


The same is also true of our social environment. You might hear of the strange finding that obesity seems to be contagious. This is really an effect due the nudging of our social environment. People around obese friends tend to develop unhealthy eating habits as a result of the behavior contagion in their social environment.


Remember that the capacity to break norms—including social norms—is an adaptability resource that is often needed to carry out non-routine or non-conforming behaviors. Creating a social environment where overeating is the norm contributes to compulsive eating being the path of least resistance.


Avoid Splashing with a Nudge in the Right Direction

urinal fly.pngThe last example is fairly well known—at least to most men anyway—the urinal fly. Who would’ve guessed that simply etching a house fly above the drain of the urinals is going to reduces spillage by 80%? This is a nudge, because it doesn’t prevent men from aiming elsewhere, nor does it change the economic incentives—you don’t win a prize or receive a badge for aiming at the fly. Conversely, you won’t be punished for mindlessly splashing other places (Unless you happen to hit the shoes of the man next to you perhaps?)


Giving someone a target, a goal, or a direction merely helps to focus people’s drifting attention. This essentially reduces the number of options by accentuating one option among many approximately equivalent ones.


The Real Power of Nudge

Because a nudge is such a subtle intervention, it often changes people’s behaviors or choices without them even knowing it. I can’t stress enough the importance of the subtlety here, because that is what makes nudge such a potent behavior driver. Nudge is powerful because it can change people’s behavior without taking away their autonomy, which is a very potent intrinsic motivator—from self-determination theory.


When designing the choice architecture of a nudge, it’s important to consider that consumers must always maintain their freedom to choose the unwanted alternatives. Moreover, these alternatives must be designed and constructed so they are approximately equal to the desired behavior—they must not be much-more-difficult or much-more-expensive than the behavior you want to encourage. In other words, consumers must be "able" to choose the unwanted behaviors just as easily and cheaply.


This is unlike anything we’ve seen before, because most behavior interventions require people to comply with certain rules, which often result in some loss of autonomy. Even gamification requires the users to opt-in to the “game” in order for us to drive the gamified behaviors. Although the best gamification strategies are those where the users don’t know and don’t feel like they are playing a “game,” users can often recognize it. They may not know precisely which behavior is being gamified, but they will recognize that they are being gamified. In that case, it can ultimately lead to annoyance, dissatisfaction and reduced engagement.


choice architecture2.pngA nudge only plays a facilitative role in driving behaviors, so users typically don’t even know that they are being nudged. Moreover, there is no neutral design in nudge, because neutrality doesn’t exist in choice architecture. Every context (i.e. environment, presentation, etc.) drives some behaviors—including doing nothing. For example, researchers have shown that the first candidate on a ballot could get 4% more votes just for being listed first. This is the true power of a nudge, because people will be nudged whether they like it or not. There is no opt-out for a nudge, since opting out is a behavior that can be designed and nudged towards.



Despite the hype around gamification, it is only one set of tools that focus on the motivation factor of the FBM to drive consumer behaviors. However, consumer behaviors can be driven more effectively if we focus on the ability factor of FBM, because simplicity is typically a stronger behavior driver than motivation. There are 2 approaches that focus on the design of simplicity to drive behaviors:

  1. baby steps—focuses on simplifying the behavior (i.e. tiny habits)
  2. a nudge—focuses on simplifying the context (i.e. the environment, the presentation, etc.)


We illustrated the power of nudge through 3 examples where little nudges resulted in huge impacts:

  1. Assuming a default opt-in for organ donation increases the organ donation rate by more than 3x
  2. Rearranging the food items in a cafeteria to make healthier items more convenient and easy to reach increases salad consumption by 300% and fruit sales by 102%
  3. The urinal fly decreases spillage by 80%


The power of nudge lies within its subtlety, and this is why nudge is able to drive behavior without diminishing people’s sense of autonomy. Consequently, consumers always have the freedom to choose among all the available options—including not choosing at all. This is what Prof. Richard Thaler—pioneer of nudge—meant when he said there is no neutral design in choice architecture. Every design nudges some behaviors in some subtle ways—including no behavior.


What this means is every time you are presented with choices, you are being nudged in some way. Keep an eye out for the nudges in your daily life. I am sure you will spot a lot more of them.


Alright, that’s it for today!


So what’s next for my blog? You’ve already learned 2 of the 3 paths for creating long-term behaviors. Should I write about the final path (i.e. intrinsic motivation) or should I take a break from gamification and write about big data? You decide and let me know. Thanks for following!


BTW—I just presented you with a specific choice… Did you feel the nudge?



Michael Wu, Ph.D.mwu_whiteKangolHat_blog.jpg is CRM2010MKTAWRD_influentials.pngLithium's Chief Scientist. His research includes: deriving insights from big data, understanding the behavioral economics of gamification, engaging + finding true social media influencers, developing predictive + actionable social analytics algorithms, social CRM, and using cyber anthropology + social network analysis to unravel the collective dynamics of communities + social networks.


Michael was voted a 2010 Influential Leader by CRM Magazine for his work on predictive social analytics + its application to Social CRM. He's a blogger on Lithosphere, and you can follow him @mich8elwu or Google+.

About the Author
Dr. Michael Wu was the Chief Scientist at Lithium Technologies from 2008 until 2018, where he applied data-driven methodologies to investigate and understand the social web. Michael developed many predictive social analytics with actionable insights. His R&D work won him the recognition as a 2010 Influential Leader by CRM Magazine. His insights are made accessible through “The Science of Social,” and “The Science of Social 2”—two easy-reading e-books for business audience. Prior to industry, Michael received his Ph.D. from UC Berkeley’s Biophysics program, where he also received his triple major undergraduate degree in Applied Math, Physics, and Molecular & Cell Biology.
Occasional Commentator
Occasional Commentator
Nudged to a "Thank You." 🙂 many framing thoughts came to mind... a nudge-artifact. A few positively resonant enough to demand clarifying effort, I suspect - to form a decent question, and then off we go...looking forward to reading more. Not what i think of as decent questions, but fun enough to toss out there: Does the urinal fly move? 🙂 And once the pissee realizes it's a artificial fly does the nudge result reverse to some degree?
Lithium Alumni (Retired) Lithium Alumni (Retired)
Lithium Alumni (Retired)

Hello @imonad,


Thank you for taking the time to comment, and glad to hear that many framing arise from this article. And remember, no question is too simple, and I will always respond.


To address your question: the urinal fly does NOT move. And even after people realized the fly is fake, the effectiveness of the nudge is still present. That is people (men) continue to aim and splash less.


It is something that is very subtle that doesn't take much mental processing, much like the default used in organ donation. People are either mindless and careless or they are nudge to the direction the choice architect designed even when they are conscious about the choice they make. 


That is what makes nudge so powerful.


Alright, thank you again for commenting. I look forward to seeing you again here.


Occasional Commentator
Occasional Commentator
I like the idea of a cognitive "path-of-nudge", similar to my "path-of-ah-ha", which one can observe with master educators, or sale people... micro nudges that generate effortless movement towards action/time.
Occasional Commentator
Occasional Commentator
hi Mike, i developed a micro-nudge design to assist people in Self-discovery, and early, in reinforcing specific memories. i realized early on in developing behaviroal change that effort was extremely difficult energetic to bring forward in an individual, so i had to come up with ways to cause the greatest amount of cognitive effort applied to managing human memeory wo/the sense or feeling of effort being called for... Cheers
Lithium Alumni (Retired) Lithium Alumni (Retired)
Lithium Alumni (Retired)

Hello @imonad,


Thx for sharing your work.


Although I see a resemblance between nudge and the path of ah-ha (i.e. enlightment), I believe they are fundamentally different. The ah-ha moment is a change of the person's mental state and often comes from learning and realization. Where as nudge is a change in the context and the environment that is external to the user. In nudge, people often are not aware that they are being nudged, but in enlightment, people are often well aware that they are being taught something and imparted with knowledge or thoughts by the educator or sales person.


So despite the fact that they are some similarity that they are subtle and drives behavior, they are quite different.


If you are trying to reduce the effort for memory recall (i.e. empowering the user with more abilities for the cognitive task), then you are actually using the baby steps approach that I described 2 earlier posts that I presented. Those are different from nudges as well.


They are all related methods for changing behavior. However, they are completely different approaches to drive behavior changes. I guess for practitioners, it doesn't really matter as long as your can drive behavior your want. But for academics and scientist, it is important to know the subtle difference between them, because some are more effective than others depending on the problem. 


Thank you again for sharing. I hope to see you again soon.


Occasional Commentator
Occasional Commentator
Hi Michael, Thanks for the nudge I did get it 🙂 I do have a few questions which I want to ask as I'm becoming more interested in behavior psychology but that's more personal interest than helping the community. Will try and find out a way to send you a message and not spoil the q & a chain here. But then to come to a decision would love to see you complete the third one of intrinsic motivation.
Occasional Commentator
Occasional Commentator

Hello @MikeW 

May be I'm asking this question impatiently without waiting for the blog on third path about intrinsic motivation.


I'll still ask/state this here out of curiosity Smiley Happy



My take is that Gamification also provides some sort of nudge,


Providing a scaffolding to make people feel an activity as easy and achievable/doable.

Providing a status as to where you stand in an activity and how much does it take to compete the activity(or giving a sort of nudge that it doesn't take much to complete the activity).

Creating a user centric design which creates a kind of satisfaction or Joy in participating or completing an action/process(A gamified Banking app providing you details of how much you are short of saving for your goal instead of your normal a/c balance is a sort of nudge(read intrinsic motivation to save).


Isn't all these some sort of a small nudge?


I understand that all these paths have to used in the respective situations/context and each has its own advantage but I would like to see the distinct advantage of using one over the other.


Will be happy to hear your views on this.

Lithium Alumni (Retired) Lithium Alumni (Retired)
Lithium Alumni (Retired)

Hello @LakshmananP


Thank you for taking the time to comment on my blog. I will try to address your question without giving any spoiler here.


First, we must distinguish the common colloquial notion of a nudge and the behavior economist's notion of a nudge. If you are talking about the colloquial sense of a nudge, than yes, gamification does nudge people to take some action. So does monetary rewards, bribe, trickery, etc. In fact, anything short of brute force coercion (or the use of command and power) will nudge people to carry out a certain behavior.


However, that is not the nudge that we are talking about here—the behavior economist’s notion of nudge. The behavior economist's definition of nudge is defined in my last post: “it is the the design and construction of choice architecturethat alters people’s behavior in a predictable way without forbidding any options or significantly changing their economic incentives.”


So if you are not designing the choice architecture or constructing it, you are NOT using nudge (i.e. the behavior economist’s nudge). If you are changing the incentive, such as most gamification does via feedback, status or rewards, you are NOT using the behavior economist’s nudge. If you are forbidding any choices that result in the loss of autonomy, then you are not nudging in the behavior economist sense.


This is an unfortunate use of the languages. Just like gamification is not about games, the behavior economist’s nudge that we are talking about here is not just about nudging people to take certain choices actions. Rather it’s HOW you get people to take those choices and actions. And you have do it through designing and constructing the choice architecture to be considered a nudge in the behavior economist.


Although gamification is still new and rapidly evolving, in the strict academic sense, gamification (at least most of the ones offered by vendors today) is not nudging (in the behavior econ. sense). They do provide nudge in the common colloquial sense though. That is why we make the distinction of the 3 paths:

  1. baby steps
  2. nudge—changing the context (or choice architecture)
  3. intrinsic motivation

Otherwise, all these paths will provide some nudge in the colloquial sense because all these are methods that drive behaviors.


Alright, I hope this make sense.


Thx for the question. I’m sure this is also a point of confusion for many other. Terminology is always challenging to get around especially when it overlaps with our common colloquial notions. So thank you for asking and giving me the opportunity to clarify this.


See you next time.


Lithium Alumni (Retired) Lithium Alumni (Retired)
Lithium Alumni (Retired)

Hello @MikeW 



Thanks for this interesting article.


I would like to ask couple of questions as nudging may seem 'to good to be true' (also for governments to change our behavior as citizens).


- Do you have counter-examples where nudging actually didn't work (or is the assumption that nudging always works if it is correctly implemented)?


- Do you think some people are more influenced by nudging than others (or do you think it only depends on the context)? And if yes, why (psychological resistance, social status, culture ... )?


- Can we anticipate the impact of nudging before implementing it? Or is it a 'implement first and test it' thing?




Lithium Alumni (Retired) Lithium Alumni (Retired)
Lithium Alumni (Retired)

Hello @DavidW 


Thank you for asking, and I’m sorry for not being able to respond earlier. I’ve been spread very thin these day—working 80+ hour weeks + weekends.


Yes, nudge does sound a bit too good to be true isn’t it. Although nothing can be guarantee to work, it is quite powerful. It works as well as if you classical and operant conditioning that work even in mice and pigeons. Basically, if you give a hungry man food, you pretty much know what he’ll choose and how he’ll behave in response. So the theory of nudge is very primal and fundamental in human behavior.


Since you mentioned the government... so I thought I share a tidbit... Nudge work so well that even President Obama have a team of behavior economist/psychologist working for him in his nudge unit in the White House. Even the British government is setting up such a nudge team. So don’t be surprise when you hear the government is nudging citizen behavior. It’s happening. The reason why these government are OK with it is precisely because of the autonomy that nudge offers. The citizen always have an alternative choice and can make that choice easily.


Now, let me try to address your 3 questions.


  1. Despite the power of nudge, it still involves the design and construction of the choice architecture. It’s a design problem. So it can definitely be designed wrong or poorly, and there are definitely poorly designed nudges that doesn’t work. For example the use of defaults. Theories suggest that this is only effectively when the choice people are making is complex and people don’t really have a way to evaluate the outcome one way or another. Pre-selecting a default that is clearly sub-optimal or don’t make economically sense, will not drive the choice/behavior you want. In fact, it will have the reverse effect and also give people a bad user experience.


  1. Yes, there is a differential effectiveness of nudge across the population. We know this because nudge does not and probably cannot drive everyone to make the same choice, however, effective they may be. But the sub-population where nudging is effective doesn’t seem to fall into any specific demographic. It is more context dependent, more specifically it depends on how much resource the person have access to at the moment, and how motivated he is to choose the alternative choice.

    In fact, nudge affect the same person differently because of this context dependence. For example, if I’m very busy today (i.e. don’t have access to a lot of time to consider all the consequence of my choices), I may go with the default today. But if I have access to more time tomorrow and more access to mental capacity to think things through, then I might choose differently.


  1. As with any design discipline, you can always anticipate the impact of nudge based on behavior economics and psychology. But behavior econ/psych is still far from a complete theory of human behavior. There are still many open problem that need research and many questions we don’t know answer to. So to that limit, we can anticipate the impact of nudge within the confine of our knowledge, and existing validated theories. But beyond that, we have to iterate and improve.


Alright, I hope my reply sufficiently address your questions.

Thank you for asking such great questions, and hope to see you again next time.


New Commentator

HI Michael,


Haven't commented here in a while.


One question: If the purpose of a nudge is to allow the user to feel autonomy in their choices, wouldn't that mean you are eliciting a behavior rather than driving a behavior?


To me the two terms imply very different emotional bases for action. One implies choice and, I would add social flow, the other implies constraint and feeling gamed. JMHO that social flow is what gamification design does when successful. Feeling gamed is what gamification design does when people feel constrained in their choices.


As always, I enjoy your writing and thoughts.


Larry Irons

Lithium Alumni (Retired) Lithium Alumni (Retired)
Lithium Alumni (Retired)

Hello @LarryIrons


Happy new years. Welcome back and thank you for commenting.


To address your question... whether it's eliciting or driving a behavior depends on who's perspective you take. If you are the designer who creates the choice architecture, you are driving a behavior. Even users have choices, they are driven to take one action over others. As Prof Thaler states, there is no neutral choice architecture. Every architecture drives something.


If you are the end users, then elicit is probably more accurate, because many times, you don't actually know that you are being driven to take a certain choices.


So, yes, there are difference, but we can also knit pick the details of the language, it is really elicit, or is it evoke, cause, etc. The educator academic of me said that it's an important distinction to make, but the practitioner side of me said that it really doesn't matter as long as we explain that users have full autonomy.


But thank you for the comment. Hope to see you back here more often.