Mirroring isn't a trick if you mean it
An FBI hostage negotiator's simplest technique is also the one people fake worst.
Chris Voss spent 24 years negotiating with kidnappers and hostage-takers for the FBI. His single most-taught technique is almost embarrassingly plain: repeat the last one to three words the other person said, then stay quiet.
He tells a story about his own son, midway through a conversation about packing "notebooks" for a training. Something in Voss's tone made the son suspect they weren't picturing the same object, so he just said the word back: notebooks? Voss, assuming his meaning was obvious, said it again, louder. The son kept mirroring — one word, flat, no charge — until Voss finally clarified: three-ring binders. His son had pictured a spiral notepad the whole time.
The move isn't magic; it's structural. Repeating someone's own words signals that you heard them precisely, which makes them elaborate, correct, or clarify — and elaboration is where the actual information lives. Voss is explicit that mirroring done as a performance, to seem empathetic, falls flat immediately. It only works as an instrument of real curiosity about what the other person means.
Most advice about active listening skips this part: the technique is only as good as the attention behind it.