There is a problem with teaching assertiveness directly to someone who is passive. When you describe assertive behavior to them as clear, direct, unapologetic, and boundaried, they hear aggression. The gap between where they live and where you are pointing feels enormous, and what feels enormous feels wrong. So they resist it, soften it, or dismiss it as "not who they are."
The same problem runs the other direction. Describe assertive behavior to someone who is aggressive, someone accustomed to dominating, controlling, or steamrolling, and they hear weakness. Too soft. Too careful. They translate "assertive" as backing down, and backing down is not in their vocabulary.
Neither person hears center when you point to center. They hear it through their own starting point.
The Overshoot Method
The way around this is to teach past the target. With a passive person, do not teach assertiveness. Teach aggression. Push them deliberately to the far side. Encourage them to hold ground, demand, push back hard, take up more space than feels comfortable. It will feel wrong to them. Good. Wrong is the evidence that they moved.
Once they have experienced what it actually feels like to operate at the aggressive end, not just heard a description of it, reining back becomes possible. Now when you point to assertive, they have a reference point on both sides. Center is no longer an abstraction. It is a felt position between two things they have actually touched.
The same method works reversed. With an aggressive person, push them toward passive. Have them practice complete deference, listening without responding, absorbing without deflecting. It will feel intolerable. That discomfort is information. From that edge, assertive is no longer "weak." It is a significant upgrade from where they just were.
"You cannot calibrate to a center you have never located. Most people have only ever stood on one side of it."
What This Reveals About Perception
The teaching method works. But it also demonstrates something worth sitting with: perception of truth is not fixed. What reads as "normal" or "correct" to any person is heavily shaped by where they started. The passive person is not wrong to perceive assertiveness as aggressive. From their baseline, it genuinely is more aggressive than what they are used to. The aggressive person is not wrong to perceive assertiveness as passive. From their baseline, it genuinely is more restrained than what they are used to.
Both are accurately reporting their experience. Neither is reporting reality without distortion. This is not a character flaw. It is how perception works. The starting point shapes the map.
This has implications beyond communication styles. Any time someone rejects a principle or a correction as "too extreme," it is worth asking: too extreme relative to what? Their objection is usually real. It just describes their starting point, not the destination. That distinction changes how you respond to resistance. The resistance is not ignorance. It is calibration lag.
Teaching Yourself the Same Way
This method is not only for other people. When you are trying to shift your own behavior and subtle adjustments are not landing, the overshoot approach applies to yourself. If you tend toward conflict avoidance, practice deliberate confrontation on low-stakes situations: not because the confrontation is the goal, but because touching that edge recalibrates what center feels like. If you tend toward aggression, practice deliberate restraint. Hold the response. Do not fill the silence. Let the other person finish.
The discomfort of the overshoot is the point. It stretches the range of what feels tolerable and accessible. A person who has deliberately practiced both extremes has a far larger usable range than someone who has only ever operated near one end.
Rein back from the overshoot and you will find assertive, or whatever the functional center is for any given skill, with a precision you could not have reached by aiming at it directly.