Zeph Smith, A student of society and humanity
Suppose you are eating lunch at a fast food restaurant, or awaiting an appointment in an office building, on an ordinary day with dozens of ordinary people around you. What are the chances that your life may be in danger in the next few minutes? Usually extremely small;
Now suppose that an un-uniformed stranger carrying a military style rifle and a large ammo clip walks in and starts looking around.
More likely than not, you will remain unharmed; they may be a responsible gun lover promoting open carry and looking for a restroom, or there may be other innocent explanations. There are way more law abiding open carry advocates than mass killers, after all.
But rationally, did your chance of being harmed soon just drop or rise, on the whole?


That vigilance/nervousness is not a misfiring instinct based on ignorance, it's consistent with rational self protection. If you don't get more nervous, there's something wrong with your amygdala and your survival instincts need tuning.
Let's take it a bit further. Suppose you had a traffic scuffle and an angry confrontation ensues; you are really upset and want the other person to take what you think is their responsibility, which they are not doing. If the other person is carrying a holstered pistol, how is that going to affect your behavior? Is it going to cross your mind that this fellow citizen just might use that pistol in their anger? Or would you be wise to trust that outcome to be highly unlikely and nothing to be nervous about? Does your answer substantially vary if you own and like guns (but are unarmed now)?
Basically any time a stranger openly carries around the means to kill or mutilate you in seconds - deliberately or accidentally - and you have no context of relative safety (eg: a gun range or hunting trip), it's survival positive to be wary. Just as you'd be wary if there were a 50 foot deep hole in your living room with no railing