I know that in certain countries like Japan or South Korea: it’s normal to leave the front door unlocked since the probaility of someone breaking in is low since their crime rate isn’t high. I knew a friend of mine who resides in Korea where they even left the car unlocked with the keys inside, can you do either of those things in America?
Growing up on a small town in Iowa, I would leave my car unlocked and windows down during the day. I lived rural and we never locked our door. Now there’s been more development near my mother’s house and she locks the door at night and when she’s not home. Someone down the street about a mile away had someone break into their house. Unfortunately for the perp, the home owner heard, grabbed a golf club and gave the dude a shiner and a titlists face tattoo.
Now I live in a larger metro area and keep my doors locked all day. I truly wouldn’t need to because we have a pretty safe community, but my wife grew up in a worse place so it’s more habit than anything. We also have dogs they could potentially pop a door open and get out, so extra piece of mind.