How to use Motivation-Reaction Units to Enhance Your Storytelling

I recently did a whole post about scene-sequel story structure. While the concept of a scene followed by its sequel is the large-scale structure (or the building blocks) of a story, Motivation-Reaction Units (or MRUs for short) are the minuscule pieces that create those blocks.  

The idea of Motivation-Reaction Units was first found in Dwight Swain’s book on fiction writing: Techniques of the Selling Writer.

Identifying and understanding Motivation-Reaction Units is a great way to improve your prose and sharpen your prowess as a writer.

Distinguishing Motivation from Reaction

Motivation is the stimulus, the event/action for the character to react to.

Reaction is the response to that stimulus

In short Motivation and Reaction is essentially Cause and Effect.

Two things to keep in mind:

  1. Motivation is external and objective

It is easy to imagine motivation as what a camera would capture if it were recording the scene. It is a stimulus placed on the character, and is consistent regardless of who experiences it. This stimulus can be captured by any and all of the senses.

2. Reaction is internal and subjective

The reaction is specific to a character. It captures the emotions that the stimulus invokes, the subjective thoughts that only a specific character can have, and the actions taken in response.

Order matters

The motivation comes before the reaction. This should be pretty straightforward because a character can’t react to something that hasn’t happened.

Ex. 1: “The storm is getting closer,” Mary said after she ran to shut the window. She had screamed when a thundering bolt of lightning electrified the sky.  (yuck!)


Ex 2: A thundering bolt of lightning electrified the sky. Mary screamed and ran to shut the window. “The storm is getting closer.”

Technically, both sentences say the same thing.

In the first example, the motivation is at the end. While the sentence still makes sense and our brains can sift through the information, it inherently slows down the reader. Not to mention, the sentence feels passive and clunky.

In the second example, the motivation is provided and then proceeded by the reaction. The information is clear, concise, and follows a logical thought progression. However, if you look at it closer, the reaction is written in a specific order.

The reaction incorporates 3 distinct parts

When a character reacts to stimuli, there will be a natural order in which they are expected to react:

  1. Initial thought/emotion
  2. Physical reflex or “knee jerk” action
  3. Deliberate action and/or speech

Not every piece is required for every motivation, but it should follow this order. This is how we instinctually process stimuli. Involuntary actions will always occur prior to voluntary actions, i.e. deliberate actions.

If you go back to Ex. 2, you see that this is done. Mary’s initial emotion is fear (which is contextualized by the scream), her physical reflex is to scream, then run and shut the window. Her deliberate speech is then shared at the end.

Following the reaction comes––you guessed it––another motivation. The cycle continues and we move on, building our story MRU after MRU.

Benefits of Motivation-Reaction Units

  • MRUs lend themselves to natural thought progression and the reader can follow along with limited confusion.  
  • They avoid the dreaded info dump. MRUs keep the scene moving, i.e., you are not stuck on a large block of description because action is consistently happening.
  • Using them helps your writing flow and makes your characters’ actions seem more plausible.
  • Readers will gain deeper connections to characters. When the reader observes how the character reacts to certain stimulus, they learn a lot about that character. It allows for the reader to understand why they make certain decisions. Readers will naturally connect to a character if they can understand and relate to their decision making.

Exceptions of Motivation-Reaction Units

Because in writing, all rules are more like guidelines.

  • There might be a time when you wish to intentionally jumble the order of the pieces. It depends on what impact you want your prose to create. Keep in mind that MRUs––with all of the pieces represented in order––will follow a logical progression. Mixing the order will instantly create a degree of obscurity or confusion.
  • Not every motivation will have all three parts of the reaction. In fact, that can feel very heavy handed if every piece is included for every motivation.
  • Sometimes dialogue is involuntary. If you are familiar with A Christmas Story, you will remember “oh, fudge”. There are times where people will speak before they think, and these moments tend to be colorful curses. You can get away with putting the dialogue earlier, so long as it is a reflexive statement.
  • Sentences that offer neither motivation nor reaction should only be included if there is a specific purpose for it. A good rule of thumb is to eliminate any piece that doesn’t fit either motivation or reaction, even if it is a beautiful piece of language.

Additional Considerations

  • The way characters react to motivation will establish their personalities and mannerisms, make sure that reactions align with your vision of the characters and is consistent to your intended perception of them.
  • Don’t have a character react in a way that is out of character just to make something in the plot happen.
  • Reactions don’t just occur from the point of view character. Everyone in the scene should serve a purpose and have a reason for being there, therefore they will also react to the presented motivations. But remember, the POV character will be the only one to illustrate internal thoughts.
  • Consider saving MRUs for editing. Writing with these mechanics in mind might cause the icy grip of writer’s block to grab you by the throat. Start by getting the words on the page. You can wait to sort through your sentences to determine if they are motivations or reactions, and then feel free to toss away what isn’t.
  • Don’t stress. You’re probably using MRUs naturally. Writers will surprisingly set things into structure for two reasons. One is that your writing is unconsciously mimicking books you have read before and those patterns stick. The second is this sort of action/reaction pattern is the natural form our brain processes information, and we, as humans, gel with that.

Utilizing MRUs is a great way to make intentional choices while writing, which will further develop a mastery over your prose.

If you found this post useful, let me know in the comments below. Message me with any content you would like to see in the future!

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