[potato3983]

In the moment it's not a question of fault or good vs bad. It's a question of who do you cast your lot in with in order to have a better chance of exiting the situation alive. Stuff like helping law enforcement or getting back at the bad guys only matters so long as it isn't likely to get you dead.

You're valuable to the hostage takers so long as you're alive. Your continued existence is a nuisance to the police. But obviously the police with their infinite money and manpower have better odds on their side. Situation specific facts must be taken into consideration, etc, etc.

[mewpmewp2]

These are all good explanations for the phenomena, and if you are being taken hostage, it is even rational to empathize with whoever took you hostage to maximize chances of your survival. I think the syndrome part is when you are out of that situation, but still continue to be kind to the hostage takers, and/or keep yourself intentionally in the dangerous situation to be with the hostage taker.