This post assumes you already understand the importance of character arcs in stories and the different types of character arcs. I will include a brief primer, but it is highly recommended that you read some books on character arcs or listen to podcasts like Writing Excuses or the Wordplay podcast by KM Weiland.

Every major character in your story needs a character arc, which is a term for change over time. There are three major arc types: positive arcs (character becomes a better person), negative arcs (becomes a worse person) and flat arcs (no moral change). Positive arcs are the most common for main characters, but not exclusive. Negative arcs are usually reserved for antagonists or tragic heroes. Flat arcs are used when the character is the impetus for change in others, usually in anthology style stories like Knight Rider, Kung Fu, Murder She Wrote, etc. Yes those are tv shows.

Most sources I’ve come across detail why arcs are important and give instructions for implementing them. Get the character’s starting point (flaws, needs, wants, etc.) and figure out their end point. Then plan some events along the way to get them from one to the other. But how do you actually do that? There’s plenty of ways, but lets look at what psychology can teach us about character development.

People rarely change. We resist it because to purposefully change is to admit something about yourself was wrong to begin with. We don’t like that. Our brains have a vested interest in keeping us the same. They use things like confirmation bias, the above-average bias, and cognitive dissonance to keep us happy in the knowledge that we are just right the way we are. Unless you’re a teenager. Then all bets are off.

This is the first step in understanding how to get a character from where they are (say, distrustful of others) to where you want them to go (part of a team). So we’ll discuss the above three things (briefly) to give you an idea of how your character will resist change, which should spark some ideas on how to implement it in your story.

Confirmation Bias - This is the tendency to seek out information that supports your opinions/views and to ignore information that contradicts it. Think of it like our highly politicized climate here in the USA: if you’re republican, you most likely ignore CNN and enjoy Fox News. If you’re liberal, its the reverse. You come up with a whole lot of “good” reasons for why you can’t trust the other sources. This is your brain tricking you. If you consume varying sources, it becomes harder to form a strong opinion, since understanding the other side weakens your own resolve and the idea that they are wrong because of who they are as opposed to what they believe. So, what kinds of thing will your character seek out or ignore in his/her quest to not change? In the above example of distrust, perhaps s/he will remember keenly every little betrayal and ignore all the times people behaved like trustworthy individuals. Or they might use news and stories of criminals to justify their beliefs, ignoring stories of valor and selflessness.

Above-average Bias - If your character suffers from depression or anxiety, this might not apply, as depressed/anxious folks tend to doubt themselves. The above-average bias is the tendency for people to think they are better than most other people. This is easy to test. Think of your friends and coworkers. Are you “better” than most of them at your job, hobby, whatever? If you said yes, you suffer from the above average bias. Or, ask a roomful of people to rate themselves on some task from 1 - 100(secretly). I guarantee when you average the results they wont be 50%. Probably closer to 75 - 85. This means your character most likely thinks of themselves as better than other people. Which means they don’t need to change, other people do. They will point to the good things they’ve done as evidence, ignoring similar acts from others. There’s that confirmation bias again.

Cognitive Dissonance - This one is a little tricky. Think of an internal contradiction. For example, maybe you consider yourself an honest person. You tell people you’re an honest person. Have you ever lied? If so, you aren’t an honest person. That contradiction is uncomfortable for most people, and your brain hates discomfort. So, to resolve it, you either have to change your view (I am dishonest) which is painful and difficult, or you find a way to reconcile the contradiction. It was a white lie, no harm done. I don’t tell big lies. It was a big lie, but it was for their own good, etc. Your character is going to do the same thing. “I don’t trust that fruit vendor, but this is how exchange works. You still can’t trust people.” This is also where you make exceptions. This one person is trustworthy, but nobody else.

There’s a lot more we could discuss. If you want, go read up on the Availability Heuristic, Narrative Fallacy, or Anchoring Bias. But let’s move on. We know how our characters will resist change, but how do we drag them into changing kicking and screaming?

Conditioning, reinforcement, and punishment. You remember Pavlov’s dogs? If not, here’s a recap: Pavlov was a scientist studying digestion. He found that he could pair the ringing of a bell with feeding a dog and get them to salivate. Eventually, they would salivate when he just rang the bell. This is classical conditioning, and it underpins a lot of our understanding of behavior.

If you want your character to change, you need to condition them to reflexively perform the new thing (trusting others in our example). There’s two different ways to do this, courtesy of B.F. Skinner’s operant conditioning research.

Reinforcement - This is when you reward a behavior. Continuing with dogs, you make them sit, then give them a treat. They associate sitting with treats (a reward) and will eventually sit on command even if you don’t have a treat. This is positive reinforcement. Negative reinforcement is a little tricky to imagine because it’s counterintuitive. Let’s say there’s something unpleasant in your dog/child’s life. We’ll go with vegetables for a child. You get them to do something (maybe eating with a knife and fork), and reward them by taking away the bad thing, in this case: vegetables.

You can use these with your character to teach them how to act through a series of events. Imagine the end state. What is something the character would value? Success is a great reward. So engineer a scene where your character chooses to do the new thing (trust someone) and is rewarded with success or the removal of something bad (easy example, trusts someone and they heal them). Now the character is a little more likely to act that way in the future, and you can engineer a bigger, harder event that pushes them further down the path. Remember the biases from above. The character might explain the change away, but the habit is forming nonetheless. Add in cognitive dissonance, and eventually the character will be forced to accept the new thing (trusting others) or be incredibly uncomfortable. This is that realization scene where the character is forced to recognize they aren’t the loser-jerk they thought they were, or that they were an idiot all along.

Punishment - This one is a no-brainer. Punish bad behavior to make it go away. Psychologically speaking, punishment doesn’t work. It just causes the subject to sublimate or hide their behavior, rather than exterminate it. But most folks don’t know that, so you can safely use punishment in a novel and most readers won’t bat an eye. Like reinforcement, there is positive punishment and negative punishment. Positive punishment is the classic: you add something to a situation after a bad behavior is performed, like spanking. Negative punishment is about taking things away, like an allowance.

Engineer scenes where your character backslides a little, doing things the old-fashioned way (distrusting, in our example). Then punish the character for it by making something worse for them, or taking away something. Maybe they distrust a guard so he takes their weapon. That sort of thing. Confirmation bias can make the character use this as an example of people being untrustworthy (corrupt guards, meh), but again, it’s still there niggling at the back of their mind. Eventually these little things will reach a critical mass and force cognitive dissonance to resolve the contradiction of their behavior and their values.

Putting it all together - So, now what? Based on the above, you should have some ideas for your character. What is the flaw you want them to overcome, or the flaw you want them to grow (for a negative arc)? If they are a flat arc character, you use them as the punishment/reinforcement for the other character’s behavior. Ask yourself what kinds of events would need to transpire to to make a person do the thing you need them to do. Think about how they’ll resist change. Remember to intermingle good and bad behavior. Reward the good, punish the bad.

In my experience, good character arcs have two or three big events culminating in the final do-or-die moment where they must change to succeed. Between those two to three events are a handful of smaller events that might fly beneath the character’s notice at first, but add up to a greater revelation toward the end of the arc.

Using our trust example, big events are trusting an enemy, distrusting an ally, needing to delegate an important task to someone else, or betrayal. Small events might be asking for directions, haggling for services, and lying or being lied to. Just remember to make each scene do more than just one of these events. It should also do world-building or plot movement. Ideally all three. Now get back to writing.