What makes a character fall in love? Is it destiny? A spark? Magic?
What if it was… chemistry? Literally.
We think of our feelings as magic. But love, fear, courage, and trust are all made of something real: tiny chemicals flowing through our brains and bodies. These chemicals are called hormones and neurotransmitters.
For a writer, this isn’t just science — it’s a hidden toolbox. What if you could use these chemicals to build your plot? What if a love story wasn’t about fate, but about dopamine? What if a hero’s bravery wasn’t about willpower, but about adrenaline?
This is a powerful way to create stories that feel incredibly real and human. Let’s break down the science of feeling and turn it into the art of storytelling.
Your Guide to the Body’s “Plot Chemicals”
You don’t need to be a scientist. You just need to know a few key players. Think of them as your cast of invisible characters.
1. Dopamine: The Chemical of Wanting
- What it does: This is the reward chemical. It makes you feel excited, motivated, and obsessed with getting something you want. It’s not about happiness from getting the thing; it’s about the thrilling chase for it.
- In your story: This is the feeling of a new crush. The can’t-stop-thinking-about-them feeling. The obsession of a detective on a case. The thrill of a gambler on a winning streak.
- Plot Idea: Your character is literally addicted to the dopamine rush of stealing. They’re not stealing for money, but for the thrilling chase and the high of getting away with it.
2. Oxytocin: The Chemical of Love and Trust
- What it does: This is the bonding chemical. It’s released during hugs, intimate conversations, and acts of trust. It creates feelings of love, safety, and deep connection.
- In your story: This is the moment two characters truly open up to each other. The bond between a soldier and their loyal companion. The unbreakable trust within a team.
- Plot Idea: In a world of con artists, one thief is hired to betray a partner. But the more time they spend together (releasing oxytocin), the harder it becomes to complete the job. Their biology is fighting their mission.
3. Adrenaline: The Chemical of Action
- What it does: This is the fight-or-flight chemical. It kicks in during danger, making the heart race, senses sharpen, and muscles ready for action. It’s pure, survival-focused energy.
- In your story: This is the chase scene. The battle. The moment of jumping off a cliff. It’s the burst of energy that lets a character perform a superhuman feat to save someone.
- Plot Idea: A character is unusually calm and sluggish. They discover their body doesn’t produce adrenaline. How do they react in a world full of dangers that everyone else runs from?
4. Cortisol: The Chemical of Stress
- What it does: This is the stress hormone. If adrenaline is the siren, cortisol is the long-term aftermath. It creates anxiety, paranoia, and a constant feeling of being on edge.
- In your story: This is the slow burn of fear. The soldier with PTSD. The whistleblower who knows they’re being watched. The constant dread in a horror story.
- Plot Idea: A character is trapped in a job that constantly floods their body with cortisol. The story is about their physical and mental breakdown, and their desperate quest to find a place of peace.
How to Weave Science into Your Story: A Simple Method
You don’t have to write a textbook. You just have to let the science guide your characters’ actions.
Step 1: Pick a Chemical for Your Character’s Motivation.
What is driving them?
- Are they chasing a dream? That’s Dopamine.
- Are they protecting a loved one? That’s Oxytocin.
- Are they running for their life? That’s Adrenaline.
- Are they constantly worried? That’s Cortisol.
Step 2: Show the Chemical’s Effect, Don’t Name It.
Never write: “She felt a surge of oxytocin.”
Instead, show what it feels like:
- Oxytocin feels like: “A warm calm spread through her chest. For the first time all day, the tight knot in her shoulders loosened. His words felt like a safe harbor in a storm.”
- Adrenaline feels like: “The world snapped into sharp focus. The sound of her own heartbeat was a drum in her ears, and every muscle was a coiled spring, ready to unleash.”
Step 3: Create a “Chemical” Conflict.
This is where it gets fun. Make two chemicals fight each other.
- Dopamine vs. Oxytocin: A character is addicted to the dopamine rush of being a famous musician (the chase, the applause) but it’s destroying their family life (their source of oxytocin). Which chemical wins?
- Adrenaline vs. Cortisol: A soldier thrives on the adrenaline of battle but is destroyed by the cortisol of constant, everyday stress back home. They miss the war because their body misses the rush.
A Story Seed: The Love Potion Lab
Imagine a sci-fi story where emotions are not magic, but a science.
A young biochemist is hired to design the perfect first date. Their job isn’t to arrange flowers, but to orchestrate a chemical reaction.
- They plan an exciting activity (like go-karting) to spike dopamine.
- They ensure the meal includes foods that help produce oxytocin.
- They create a moment of slight, shared danger (a walk along a scenic but safe cliff path) to trigger a little adrenaline, which bonds people.
But then, the chemist realizes they have developed real feelings for their client , a genuine, chemical reaction of their own that wasn’t part of the plan.
The plot isn’t about magic; it’s about the messy, unpredictable humanity that gets in the way of perfect science.
Your Invitation to Experiment
Your characters are biological machines, powered by chemicals. Thinking about their drives this way can make them feel more real and their choices more powerful.
The next time you’re figuring out a character’s motivation, ask yourself: “What chemical is driving them right now?”
The answer might just be the key to unlocking your next great story.
What’s a character decision you’ve struggled with? Try explaining it with a chemical in the comments! Let’s brainstorm together.