Is Bias a Survival Instinct?

Trigger warning: this may upset some of you. Mods don't delete. Just delete comments as I think this could be an interesting discussion.

Yesterday we had a speaker come in to talk about bias. She was REALLY good and it was a great presentation. Obviously we know what bias is. It's not a difficult concept to understand but we forget about it all too easily. I personally have been actively trying to expand my awareness and have less bias to people. "maybe that dude is tailing me cuz he's on his way to the hospital or because he is about to poop his pants". "maybe that lady is pissed off because she just lost her job and her friend died". There's so many unknown variables about people, we really shouldn't judge a book by its cover.

The one topic she went into depth was implicit bias and how we need to try to be more conscious to not prejudge people blah blah blah. Ya know the normal spiel. I'll agree implicit bias is usually wrong a lot of the time. We can all do better in this aspect.

But it got me thinking, is implicit bias a survival instinct? Does this subconscious process and action actually protect us from threats? Is it human nature? I'd argue yes if it is used in the sense of protecting yourself. You can't trust everyone nor should you blindly trust people without your own personal vetting process. It's ok to prejudge some things while still being politically correct.

Prime example: Columbus has had the highest number of homicides this year ever and we still got a month and half to go. 75% of those homicides are black victims with a majority committed by black suspects. A good amount of them are committed and upon people under the age of 18. Columbus has a terrible 52% clearance rate on homicides. We are well aware of what areas crime is higher. Today two 14yr olds tried to hold up a 75yo man at gunpoint who was volunteering for meals on wheels in broad daylight. Well the 75yo was a retired cop and well he's more accurate with a gun.

So the question I pose is why shouldn't I be on higher alert when in those areas at various times of the day? There's killers free all over the city. Or why shouldn't I pay a little more attention to that person walking my way? Age does not matter- I will judge you. In a bad area- I'm gonna be a bit more suspicious than if I'm in the richest part of town. Driving though the hood at night- you sure bet I'm locking my doors. Plenty of car jacking that way.

I'm from Youngstown which is a shit hole. My wife is from a rich area in Cleveland. She had no concept of inherent risks in bad areas. She had no clue some rando walking up to you in the parking lot of Walmart at 9pm could end badly. Stopping to help that broke down car in the hood at midnight, might be a trap- just call the cops to go help them if you're so inclined. Being too nice or too trusting can be harmful to your health. Period.

Tldr: if this makes me racist, then fuck. I'll judge anyone but I'll also try to make an effort to open a dialogue if the opportunity presents. I will not reply to this thread.