Have you played the Silent Hill series?
The characters don't care at all.
Not totally true, there's usually reasons for that if so. I mentioned Henry before, as well as James having in-story reasons for their reactions, or lack of at times.
Heather and Murphy have perfectly normal reactions- Heather in fact is extremely human, but she's also pretty strong willed so it takes a lot to rattle her fully. Alex is a bit stifled, but again, there's a reason for that and he's otherwise reacting as expected. First game I don't remember much.
There's an unnatural quality about most of the side characters in the games that would explain their reactions as well- they don't seem quite right in many cases.