A strong claim in "Never Split the Difference"
In Chris Voss' manual on negotiation (on p. 228 of my copy):
If you were able to take an armed kidnapper who’d been surrounded by police and hook him up to a cardiac monitor, you’d find that every calibrated question and apology would lower his heart rate just a little bit.
And that’s how you get to a dynamic where solutions can be found.
I wonder if this is true?