A crash course in changing the world.
Trust in authorities will prevent people from panicking. It will enable individuals to better cope with their fears, act more rationally, and support each other. It will allow people to accept more drastic measures such as quarantines and school closings.
I think this is one of the best secrets because it teaches that in a crisis there needs to be someone in charge. Otherwise people start making rash descions and things get worse.
If there is an authortive figure who is not trusted it is just as bad as not having anyone in charge at all. People need someone they can rely on during panicky times otherwise it slows the process of putting things right down.