The problem with telling people they need to be "more scientific and less emotional" when dealing with fear or threats, is that it doesn't work.

If they knew how to be more logical, there wouldn't be a problem in the first place. They don't. And just saying you "should" is not enough. It doesn't enable them to be more logical.

Communication that produces better outcomes requires to put the focus on why the threat isn't a threat and STOP. There is no need to tell people, beyond that they are illogical in the way they are handling fear. Good communicators, with the skill to reduce threat perception of everyone in the room do it all the time. And they produce better outcomes.