"I'm just sensitive"
Some readers will say that this is just who they are. They pick things up. They notice the shift in a voice, the half-second before a reply, the look that others miss. It's a quality, and a book that wants them to stop noticing wants them to be someone else.
I'd agree that noticing is a quality, and I want to separate it from the reading, because they've been fused and they're not the same act.
Noticing is perception. Your partner is quieter than usual. Your manager's email is shorter than usual. The friend's reply took longer than usual. All of that is true, and noticing it is a skill, and I'm not asking you to lose it. A person who notices these things is more useful and kinder than one who doesn't, because they can ask, and offer, and adjust.
The reading is a second step. It takes the noticed thing and supplies a cause, and the cause is you. That step isn't perception. It's inference, and it's the inference that Fenigstein, Epley and Gilbert's work is about, and it runs wrong in a known direction. The sensitive person and the person who takes things personally do the same first step. They part at the second.
Here's how you can tell them apart in yourself. Noticing produces a question. "They're quiet. I wonder what's happened." The reading produces an answer. "They're quiet. It's because of the bins." If what arrives after the noticing is a question, you've noticed. If it's an answer with you in it, you've read.
There's a test for which one you did, and it's the second sentence. After "they're quiet", what came next? If it was "I wonder if the meeting went badly", you noticed and then wondered, and the wondering had them in it. If it was "it'll be the bins", you noticed and then read, and the reading had you in it. The second sentence is where the two paths split, and it's the second sentence the method works on.
So keep the noticing. It's the part that makes you good company for people having a bad day, once the reading gets out of its way. What the book asks is that after you notice, you hold the question open for long enough to write the other account, and that's a smaller change than becoming someone else. It's noticing, then a pause, then a question instead of a verdict.