Over the past week and a half, I’ve been writing about factors that are going to influence how characters react to something that scares them. Now let’s put it all together and look at a step-by-step process for writing a character’s fear reaction.

First (assuming an immediate threat), let the instinctive, startle-reflex reaction hit: fight, flight or freeze? There are two big deciding factors here that I’ve seen. One is the kind of reflex that comes into play—at a not-quite-conscious view of the situation, is this something to confront, to run from, or [Need more information, loading, loading, loading]? The other is just how strong a startle reflex the character has, to figure out what kinds of stimuli trigger it and by how much; mine, for instance, is pretty strong, so I’ve been known to tense up at the sound of a phone ringing if it was close to me.

Second, figure out whether this is actually something that they’d be or stay afraid of once the moment of instinct had passed—there’s a difference between jumping back because of a butterfly flying unexpectedly towards you and actually being afraid of butterflies. This is where you start applying categories of fear, duration and immediacy; use the character’s fear profile to figure out how intense her fear actually is, and start to act accordingly.

Third, apply response and coping mechanisms. What’s the character doing about the situation that causes her fear itself? Is there anything she’s trying to do to decrease the fear’s overall effect? How well is that working out for her? Responses tend to operate one at a time, though they may change as one response demonstrates itself ineffective; coping mechanisms, on the other hand, might stack, and might continue even if an overall response fails. Don’t forget the role that fear plays in the character’s life; that’s probably going to influence her response and overall mental state.

Consider also the matters of sensitization and habituation. These are results of exposure to fear stimuli that change how a person’s likely to respond to them. Sensitization, as the etymology suggests, makes a person more sensitive to certain sources of fear—a person who’s hiding from a serial killer in an abandoned house might be particularly sensitized to signs of visitors like footsteps or voices. Habituation goes the other way—the person’s so used to a certain kind of threat that they stop throwing quite so much energy at being afraid of it. If either of these comes into play, it’s going to have a visible effect on your character’s reaction.

What happens if a coping mechanism, or a response, completely fails, or can’t be implemented to begin with? Some people are more adaptable than others, likely to jump from one solution to the next with only a slight increase in fear; others might break down entirely at the first failure. It doesn’t even need to be a complete failure; a particularly fragile individual might freak out and move on to a greater stress reaction at the first sign on trouble, while an impatient one might move on to a new plan before the first has had time to take effect properly. Some people go straight to the greater stress reaction if they just plain can’t execute Plan A, others will consider and discard a few other potential options before the greater stress kicks in.

And there you have it: a simple yet customizable outline for a character’s fear reaction. Have fun!