Dual Process Theory: How to Market to System Two

System 2

What drives your decision-making? Trick question. Two drivers are behind the wheel: system one and system two.

Which system is driving right now? Which system was driving when you bought that new house? How about when you solved difficult math problems in Grade 11?

As it turns out, logic is literally a scarce resource. So, if you’re making a truly rational argument, you’ll want to ensure you’re optimizing for system two. [Tweet It!]

What Is System Two?

System two is part of the dual process theory, which explains how something can happen in two different ways as the result of two different processes. The theory states that there are two different systems in the brain. The other process being, of course, system one.

(Last year, I wrote an in-depth explanation of system one, also known as the reptilian brain. Take the time to read through it now before continuing with system two.)

These two systems, developed through evolution, are responsible for our decision-making. However, they approach decision-making in two very different ways…

The two are almost exact opposites. System one is instinctual, fast, and emotional while system two is rational, slow, and logical. System one is automatic and requires little effort to use. System two is controlled and requires effort to use. System two is easily defeated while system one is always on.

So, when do you use system two to make decisions? Daniel Kahneman, author of Thinking, Fast and Slow, gives a few examples…


Daniel Kahneman, Thinking, Fast and Slow:

“The highly diverse operations of System 2 have one feature in common: they require attention and are disrupted when attention is drawn away. Here are some examples:

  • Brace for the starter gun in a race.
  • Focus attention on the clowns in the circus.
  • Focus on the voice of a particular person in a crowded and noisy room.
  • Look for a woman with white hair.
  • Search memory to identify a surprising sound.
  • Maintain a faster walking speed than is natural for you.
  • Monitor the appropriateness of your behavior in a social situation.
  • Count the occurrences of the letter a in a page of text.
  • Tell someone your phone number.
  • Park in a narrow space (for most people except garage attendants).
  • Compare two washing machines for overall value.
  • Fill out a tax form.
  • Check the validity of a complex logical argument.” (via Scientific American)

Most of the time, system two is absent. It accepts system one’s suggestions and rationalizes those instinctual, emotional thoughts.

For example, you bought the product because System 1 was influenced by an emotionally persuasive ad. System two will back that purchasing decision, but rationalize it by deciding the product was a necessity or the best quality or the cheapest price.

Since you’re only conscious of system two, you’ll accept system two’s rationalization. You will believe you made the decision for rational reasons.

Sometimes, however, there’s a decision system one can’t make on its own, so system two is called upon.

Why Is It Important?

System two is important if you identify with one of these three statements…

  • My product is truly logically the best choice. Competing products have nothing on us.
  • My product is very complex and can be difficult to understand / use.
  • My product is expensive. Buying it would be a big financial commitment.

Of course, system one and system two work together. You can’t specifically “talk to” one part of the brain and leave the other out of the conversation. That’s just not how it works. However, you can optimize your site to more deliberately call upon system two and trigger rational, logical thinking.

The two systems are not black and white. Just because system two made the decision, doesn’t mean it was the best one. System one can make perfectly logical, useful decisions. Similarly, system two can make incredibly poor decisions.


Daniel Kahneman, Thinking, Fast and Slow:

“It is self-evident that people are neither fully rational nor completely selfish, and that their tastes are anything but stable.” (via Thinking, Fast and Slow)

Understanding how the two systems work, both separately and together, is the key to understanding how to persuade your audience. If it’s not clear, you could be left optimizing for one half of the brain. And who’s to say that half will be the decision-maker this time around?

What Are the Pillars of System Two?

There are four core factors that define system two: pleasure, self-control, easily depleted, and easily distracted. If you can find ways to use these factors to your advantage, you’ll be able to appeal to system two.

1. Pleasure

System one is more concerned with avoiding pain than gaining pleasure due to its primitive nature. System two has the luxury of making decisions based on what will give you the most pleasure, now and in the future.

For example, when using a trip planning site like Kayak


… system two is more interested in getting to go on a trip for less money (pleasure) than avoiding the hassle of manually finding the cheapest price (pain).

This is partially because system two is able to consider the future. System one, on the other hand, focuses on the present.

2. Self-Control

Since system two has the ability to be future-focused, it must exercise self-control. For example, if the trip via Kayak is too expensive, system two has the restraint to say, “This will put me in a bad spot financially for the next six months. I better wait.”

System one isn’t able to do that. It only thinks about right now. So, if system two is busy working on something else, you’re more likely to give in to temptation. More or less, system two is your willpower.

Kahneman explains it with a chocolate cake example…


Daniel Kahneman, Thinking, Fast and Slow:

“It is now a well-established proposition that both self-control and cognitive effort are forms of mental work. Several psychological studies have shown that people who are simultaneously challenged by a demanding cognitive task and by a temptation are more likely to yield to the temptation.

Imagine that you are asked to retain a list of seven digits for a minute or two. You are told that remembering the digits is your top priority. While your atten­tion is focused on the digits, you are offered a choice between two desserts: a sinful chocolate cake and a virtuous fruit salad.

The evidence suggests that you would be more likely to select the tempting chocolate cake when your mind is loaded with digits. System 1 has more influence on behavior when System 2 is busy, and it has a sweet tooth.

People who are cognitively busy are also more likely to make selfish choices, use sexist language, and make superficial judgments in social situ­ations.” (via Big Think)

If your resolution is to eat better, go to the gym, and lose weight, you’re more likely to slip up when system two is busy or tired.

For example, imagine you’re having a stressful, busy day at work and you finally get home at 9 p.m. That’s when you’re most likely to snack (i.e. eat the chocolate cake).

3. Easily Depleted

So, why does that happen? Because system two is easily depleted. Again, logic is a scarce resource.

System one has a large capacity, meaning it can be always on without issue. System two has a much smaller capacity, meaning it gets tired and begins defaulting to whatever system one thinks, even if it’s needed.

Bart Schutz from Online Dialogue explains…

Bart Schutz

Bart Schutz, Online Dialogue:

“One of the results of our limited mental capacity is that our System 2 depletes during the day. We make more rationally controlled decisions in the morning, and more emotional ones at the end of the day.”

Every decision made, every complex problem solved, etc. depletes system two a little more. Once its depleted, it’s gone until you rest and it’s replenished.

4. Easily Distracted

Attention is also incredibly scarce. System two is quite easily distracted, yet requires a good deal of focus. Furthermore, every distraction depletes system two a little more each time. It’s an unfortunate combination for optimizers.

It puts the onus on you to manage attention as best you can. If you want your visitors to make a rational decision, you want to prevent system two from depleting. Thus, you want to eliminate distractions so that system two can focus.

How Can You Optimize for System Two?

So, if your goal is to prevent system two from depleting so that it’s around to make a rational purchase, where should you start? There are some basic optimizations you can make: add an element of surprise, use intuitive design, remove choices and energy drainers, stick to the facts, and choose your timing carefully.

Of course, now that you understand the science behind system two to some degree, you can come up with a whole list of other optimization ideas. For now, these five will be a good starting point.

1. Add an Element of Surprise

If you recall, system two is normally absent. As Bart says, sometimes system two is “sleeping”. Since you’re relying on it to make the purchase, you’ll need to “wake it up”. The best way to do that is to introduce something system one can’t automatically handle on its own.

Here’s how you can apply it…

  • Use popups that present a choice. This element of surprise will trigger system two to make the decision. Be sure that your popup copy is simple and straightforward. You want to wake system two, but you don’t want to present a choice that will deplete it.
  • Use alerts that present a choice. Even something as simple as a Qualaroo alert asking, “What is the likelihood that you would recommend this product to a friend or colleague?” can wake system two.
  • Use surprising imagery and copy in choice locations. Anything that system one isn’t expecting to see (based on experience and mental prototypes) will trigger system two. Place this imagery and copy near decision points (e.g. product search, product pages, checkout).

Good Example: KlientBoost

Check out this popup from KlientBoost…


The popup appears immediately and presents a choice: subscribe or confirm that you like your marketing crappy. This simple act will wake up system two.

2. Use Intuitive Design

So, what is intuitive design? Here’s how Peep explains it…


Peep Laja, CXL:

“The main thing about intuitive design is that it’s invisible. Design is intuitive when users can focus on a task at hand without stopping even for a second. Intuitive designs direct people’s attention to tasks that are important. In the end, an intuitive design focuses on experience.”

Once system two is awake, you must be careful not to deplete it. If your design isn’t intuitive, you’ll deplete system two very quickly. Why? Because before your visitors get to the purchase point, they’ve made countless decisions…

  • Am I on the right page?
  • What’s the next step here?
  • Should I click this one or this one?
  • Does this lead to the product page?
  • What does this button do?
  • How do I add this to my cart?
  • When does my free trial start?

Intuitive design elements eliminate these types of questions to the point where navigating your site and funnel feel like second nature. As a result, system two does not need to put in work, meaning it does not get depleted.

Here’s how you can apply it…

  • Focus your visitors. You might want your visitors to take multiple actions (e.g. purchase and subscribe to your newsletter), but you must have a most wanted action on every page. Your job is to focus on that action and make completing it as intuitive as humanly possible.
  • Use visual cues to direct attention. You can use subtle arrows, you can use not-so-subtle arrows, you can use the gaze of the people in your images (e.g. the little girl in the featured image of this post is looking at the quote, directing your attention to it).
  • Use contrast to demand attention. Be sure your most wanted action contrasts the rest of your site so that it’s near the top of your visual hierarchy. Contrast can also be used to separate blocks of text on a long home page and keep eyes moving downward, for example.
  • Use prototypes. For example, if you visit an agency site, you expect to see “About”, “Services”, “Case Studies”, “Blog” and “Contact Us” in the navigation. You’d be surprised to find any of those missing. Why? Because that’s the prototype of an agency site. Match prototypes so that your site feels familiar.

Bad Example: Bath Magic Inc.

Take a look at this eCommerce site…

Bath Magic Inc.

Does it look anything like you expect an eCommerce site to look? Aside from the distracting design elements, it’s completely unintuitive and strays too far from the prototype of an eCommerce site.

Good Example: BustedTees

Now take a look at BustedTees…


Cart and checkout are in the top, right-hand corner. Product sorting options are down the left-hand side. There’s a large promotional banner below the navigation. There’s a search bar in the top, right-hand corner. All of these elements match the prototype of an eCommerce site, making it more intuitive.

3. Remove Choices and Energy Drainers

You know that system two is easily distracted and easily depleted. That means your focus should be twofold:

Once you lose attention, you lose system two. Why? Because system two requires focus. If attention is divided in a million directions thanks to distracting design and copy, system two can’t work its magic.

This raises an interesting question about choice. Is offering choice a distraction or a welcome benefit? Alex Birkett explored that question in-depth last year.

Barry Schwartz, who wrote The Paradox of Choice, offers an answer as well…


Barry Schwartz, Professor of Social Theory and Social Action at Swarthmore College:

“All of this choice has two effects, two negative effects on people. One effect, paradoxically, is that it produces paralysis, rather than liberation. With so many options to choose from, people find it very difficult to choose at all.

I’ll give you one very dramatic example of this: a study that was done of investments in voluntary retirement plans. A colleague of mine got access to investment records from Vanguard, the gigantic mutual-fund company of about a million employees and about 2,000 different workplaces. And what she found is that for every 10 mutual funds the employer offered, rate of participation went down two percent.

You offer 50 funds — 10 percent fewer employees participate than if you only offer five. Why? Because with 50 funds to choose from, it’s so damn hard to decide which fund to choose, that you’ll just put it off until tomorrow. And then tomorrow, and tomorrow, and tomorrow, and of course tomorrow never comes.

Understand that not only does this mean that people are going to have to eat dog food when they retire because they don’t have enough money put away, it also means that making the decision is so hard that they pass up significant matching money from the employer.

By not participating, they are passing up as much as 5,000 dollars a year from the employer, who would happily match their contribution.” (via The Paradox of Choice)

Bart has written about the Hobson’s+1 Choice Effect, which essentially means you should offer two choices to deplete system two. So, since you’re looking to preserve system two, you’ll want to offer fewer choices.

There’s a big difference between a simple “wake up call” and a lot of thought-provoking questions near a call to action.

Here’s how you can apply it…

  • Identify points of distraction on your site through heuristic analysis. With a couple of colleagues, look for design and copy elements that might be distracting visitors from your most wanted action. Record your findings, make suggestions for improvement and begin optimizing.
  • Identify choices on your site through heuristic analysis. Where are they located? How close are they to calls to action? Are they difficult choices? When you can, eliminate them. Leaving too many choices on your site will deplete system two in the blink of an eye.

Good Example: Postmates

Take a look at this site…


Is anything distracting you from entering your address? Your choices are to login or enter your address, which is an easy one. Either you have an account or you don’t – simple. System two isn’t under pressure to avoid distractions or make multiple decisions.

4. Stick to the Facts

Now, since you’re trying to persuade the rational part of the brain, sticking to the facts and figures is paramount. System two will make the logical choice, which means you need to present your case. Why are you the most logical choice? Why not your competitors?

There is one caveat here. You must be careful not to make Descartes’ Error. Rene Descartes believed in separation of mind and body, logic and emotion. That was his error. While system two is more logical and system one is more emotional, they are not separate.

Treating them as completely separate would be a mistake. They work together, relying on one another. Your job is not to pretend that you can optimize for “logical people” or “emotional people”. Your job is to understand how the two systems work together so that you can better understand human behavior and persuasion.

Just because you’re optimizing for system two does not mean you can completely disregard system one and emotion.

Here’s how you can apply it…

  • Make it easy to compare the benefits and features. If you’re a SaaS site, list out the features of each of your plans and make it easy to compare them (e.g. in a table). If you’re an eCommerce site, list out the product specs, provide reviews and ratings, show similar products, etc. This will reassure visitors that they’re making the best, most logical choice for them.
  • Make it easy to compare price. How much money will visitors save if they pay annually vs. monthly? How much do they save per month by choosing the Pro option instead of the Basic option? How much do other companies charge? How much are they saving on this product?

Good Example: Amazon

Here’s an Amazon product page…


Note that you can see “Other Sellers on Amazon” and confirm that they’re all selling for $169.99. To a visitor looking to make a rational decision, that’s extremely helpful. It says, “Don’t look elsewhere. We already did. Here are the options. You don’t have to worry that this option is too expensive.”

Great Example: Hootsuite

Now take a look at Hootsuite’s pricing page…


All of the features and benefits are listed side-by-side for easy comparison. This is the type of information system two thrives on.

5. Choose Your Timing Carefully

System two is also quite slow compared to system one, which makes quick decisions. System two is more methodical, choosing to weigh options and carefully consider potential outcomes. As a result, your visitors may visit multiple times before making a purchase.

Knowing your audience and understanding when their system two is most awake can be incredibly valuable. You can do this by creating a heat map using your Google Analytics data and a custom report…

Google Analytics Custom Report

Here are the steps you will take to create your heat map…

  1. Create a custom report in Google Analytics. Choose “Flat Table” as your report type.
  2. Your dimensions will be “Day of the Week” and “Hour”.
  3. Your metric(s) will be “Average Conversion Rate”.
  4. Export the report data to Excel.
  5. Insert a pivot table and add conditional formatting to color-code the table.

Once your heat map is ready, you’ll be able to see how your average conversion rate changes based on the time of day and the day of week. This will also show when system two and system one are most active, which you can use for advertising campaigns, email campaigns, etc.

Here’s how you can apply it…

  • Capture emails for a drip email campaign. If you’re finding that your visitors aren’t making a decision right away, you can persuade them to provide their email address instead. That way, you can enter them into a drip email campaign and continuously communicate the rationality of the choice you want them to make.
  • Use your heatmap data to launch a retargeting campaign. Now that you know when to target your visitors, launch a retargeting campaign (using a tool like Perfect Audience). If visitors didn’t convert the first time around, an ad reinforcing the rationality of the choice at a time when system two is most likely to be “awake” might help.
  • Use multiple calls to action. Since system two is slower, visitors will want to read up on your product or service. As they scroll down, they are likely moving away from your above the fold call to action. Be sure to include additional calls to action since visitors might only be ready when they’ve read over half the page’s copy.


There are two systems inside your brain, but they are not separate. They take turns driving. Sometimes one is steering while the other works the gas pedal. [Tweet It!]

Optimizing for system two means protecting a scarce resource: logic. It means keeping system two awake and preventing it from being depleted before the purchase decision.

Here’s how you can optimize for it…

  1. Ensure it makes sense for your site to optimize for rational buyers. More often than not, products are not the most rational choice.
  2. Add a simple, easy to understand element of surprise (e.g. a popup or alert) to “wake up” system two.

  3. Use intuitive design to reduce the burden on system two, preventing it from being depleted.

  4. Identify and remove choices and energy drainers that will deplete system two.

  5. Present the facts and figures, but don’t go so far as to make Descartes’ Error.

  6. Create a heat map to see how your average conversion rate changes throughout the week, which will show you when each system is most active.

  7. Use email and retargeting campaigns to accommodate system two’s slow decision-making.

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  1. Great info Shanelle.

    I’m wondering if the above is true across all sectors. Ie, if a site is highly technical and appeals to analytic thinking vs a site for a museum or gallery. Just a thought. Wondering if you have any data on that.


    1. Avatar photo

      Thanks Trevor! Glad you liked it.

      I wouldn’t say it’s industry-specific. Instead, think of it this way: Is your most wanted action the most rational decision your visitors can make?

      Usually, the answer isn’t yes.

      If it is yes, you’ll want to do everything you can to keep system two “awake” to make key decisions.

      If it’s not yes, you’ll want to optimize for system one…


      Remember, they both work together, so it’s not as simple as “talking” to one half of the brain at a time.

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Dual Process Theory: How to Market to System Two