Why did I spend the last hour on social media? I’m supposed to be working! 

Why did I eat all that dessert? I’m supposed to eat healthier!

Why am I smoking this cigarette? I’m supposed to have quit!

Chances are you have recently asked yourself something very similar. You have somehow ended up doing something that goes against your best interest and you’re not sure why.

This is what life feels like for David. He always seems to do and remember the wrong things.

  • David never forgets to empty the snack bowl in the kitchen, but always have to throw away forgotten old fruits and veggies from the fridge.
  • He never goes a day without staying on top of his social media, but he always forgets to read that interesting book he bought last summer.
  • David finds it easy to spend his wages on cool new electronics, but struggle to save for that tropical holiday he is planning with his girlfriend. 

David feels like there is a subtle force pulling him towards doing what he doesn’t want to do and away from the things he wishes he did more often. Well, I’m here to say that the force is real. Wait, hold on Star Wars fans, I’m not talking about that force, I’m talking about one called triggers.

This is the third part in a series of articles on how to design behavior. See the previous parts on Ability here and Motivation here. To make sure you don’t miss the last part, join my newsletter here.


A trigger is best described as call-to-action. “Trigger” is the technical, behavioral word, but you might know them as cues, reminders, or prompts. The purpose of triggers is to nudge us towards taking action and doing a behavior.

To illustrate, consider answering the phone. We have the phone in our hand (able to answer), and it’s the most important call of our life (motivated to answer), but if we have disabled the ringtone and vibration (the trigger), we will still not answer.

It could be Leonardo Di Caprio on the other line, but without the trigger, nothing is nudging us to pick up the phone. Instead, we are left hoping Leo leaves us a voice message. In this scenario, there is simply no call-to-action (no pun intended).

So let’s now dig a bit deeper into triggers and see why they matter in behavior change.

Internal vs. External Triggers

The most important distinction to make with triggers is the difference between external and internal triggers.

External triggers are anything in your environment that tells or remind you to do something. It could be a post-it note, a billboard, or a phone notification. It is something external nudging you to do something. 

Internal triggers are any feeling or emotion that tells or remind you to do something. Typical examples of this are feelings of hunger, thirst or sleepiness and emotions like boredom, loneliness or sadness. It is some signal from your body nudging you to do something. 

Understanding both of these types of triggers are essential for becoming a great behavior designer. However, we will start in this series by looking at external triggers since they are more easily understood.  

External Triggers

External triggers are our environment nudging us along. What we eat, buy and do is very much dependent on the external triggers we encounter in our lives. 

If your office happened to be next to a bakery, the aroma of fresh bread will likely trigger you to feel the daily urge of consuming a fresh croissant.  

It is doubtful however that you will go and see the next Avengers movie if there is no trailers, billboards or advertising for it. If there is nothing triggering you to visit the cinema, you probably won’t see it

The good news is that we aren’t helpless. We have the ability to design an environment where good triggers are in place, and bad triggers are removed.

To understand this better let’s look at what types of external triggers exist.  

Types of External Triggers

Stanford professor BJ Fogg has identified the following three types of external triggers (1).

  • Spark: Helps when you are able, but not motivated to complete a behavior. An example of this is advertising. Ads and marketing messages are often types of spark triggers; they want you to buy something you are not currently motivated enough to buy.
  • Facilitator: Helps motivated people who lack the ability to complete a behavior. Facilitator triggers make the action easier or at least seem easier. A typical example of this is the instructions given when setting up a new phone or computer.
  • Signal: Helps people who are both motivated and have the ability to complete a behavior. The primary purpose of the signal trigger is to make us aware or remind us of something we can and want to do. It could be everything from a calendar reminder or a text message notification.

Hot vs. Cold Triggers
What makes a trigger hot is when it helps you to take action right now. A good example of this is a phone notification which allows you to just swipe and directly access the app or answer the text message. 

A cold trigger encourages action when there is no opportunity to take action. A good example is advertising. Imagine seeing a billboard along the highway telling you to watch a new movie. The problem is that there is no way for you to do that while driving (at least until we have self-driving cars).

To understand this better, let’s look at how David could use this to form a running habit. 

Example: Exercise

Spark: Here David is seeking to get more motivated to run. To achieve this, he could use motivational reminders to get him more excited for his upcoming run. It could contain a message of why running is important to him and what running today can allow him to achieve in the future.

Signal: The purpose here to help David become more able to run. If he knows that he often forgets his running gear, this could be a notification reminding him to bring it. If there is something regarding his running technique that he does wrong and often forgets, he could set mid-run reminders to correct it.

Facilitator: Here David just wants to make sure he never forgets a running session. A facilitator trigger could, for example, be a calendar reminder telling him that his run club session is happening tonight.

Hot vs. Cold: This is pretty obvious, but David wants to make sure that any trigger he sets is actionable. He wants to get his running technique reminders while he is running and get reminded to bring his running gear while he is getting ready for work. What’s the point if he is told to bring his shoes when he is already at his office. 

Be Trigger Happy

When it comes to any behavior change, the first thing you should always consider is the trigger. For a desired behavior or habit, you want to make sure the right trigger is in place. For a undesired behavior or habit, you want to make sure you remove the triggers.

You should start with triggers because they are often easy interventions to make. If you forget to do the desired behavior, create a better reminder. If you feel stuck in a bad habit cycle, just remove what is starting the cycle.

While you hopefully now better understand some of its applications, remember that triggers can be very diverse. Like BJ Fogg says, It can be anything that tells you to “Do this action now!”.

Master The Force

When you start understanding this concept, you begin to realize that there are triggers all around us. Our alarm clock, our Facebook notifications, our inbox alerts, our hungry stomachs, and the list goes on. Hundreds of triggers gently nudge us along and shape our daily routines.

Part of making a great trigger is understanding the context (spark, facilitator, and signal) and then determine a suitable frequency of how often the trigger should occur. Frequency is a balancing act similar to Goldilocks adventure in the bears’ house.

If it is too low, we might not engage enough in the behavior and do it often enough to create a habit. If it’s too high we might get desensitized or annoyed to the point where we remove it. So it needs to be just right.

What usually works best is to start low, and then over time experiment with higher frequencies. Experimentation like this is one of the cornerstones of a good behavior designers arsenal.


Focusing on the trigger is a good place to start as it is easy to change and more often than not the only thing needed to achieve our behavior goals. It is true that a well-designed trigger can make all the difference.

This was the case for David. He started to take note of the triggers existing in his life and took actions to improve them. With small changes, he now lives a life where he does what is in his best interests, at least most of the time. 

The fruits and veggies now have center stage in his kitchen while the snacks are somewhere in the pantry. He finally finished reading his book thanks to turning off his phone notifications and placing his book next to his bed. Lastly, he was able to finally afford his tropical vacation! Being aware of the influence advertising have of triggering him to buy new electronics lead him to setup so that 20% of his wages were transferred straight into his holiday savings account. 

Sitting on a tropical beach, he now has the perfect excuse to never take off his cool sunglasses. Looking good, David!

So, if you are designing for a behavior, first make sure the right triggers are in place. Once you’ve got the triggers working it will start to feel easier to live a good life. More of your good habits will seem to start happening by themselves. Therein lies the power of triggers.

May the force be with you.


We are almost there, just one part left in this series! The final part of this series will bring together all that we learned and help you design your first behavior. Check it out here. 

Until next week, happy designing.
– Samuel

Ready to level up?

Enter Level 1 – Ability.
Enter Level 2 – Motivation.
Enter Level 4 – Get Started


  1. B. J. Fogg, B. (2009). A behavior model for persuasive design. 40. 10.1145/1541948.1541999.
    I recommend you also check out BJ Fogg’s behavioral model website here.

Share this post

Pin It on Pinterest

Share This

Share this post with someone!