The culprit in destroying the safety of the neighborhood?
AIR CONDITIONING for the home;with TV as an accomplice.
With the house now a cool refuge from summer's heat,no one needed to sit on the porch for the breezes and shade that made it better than a closed house.Without those millions of adults quietly reading the paper,talking,listening to the ballgame on the radio ,and casually watching the streets and sidewalks the world became less safe.People turned their backs literally on their neighbors.Rare is the TV that could be viewed comfortably in the brighter ambient light outside of the house,so TV viewers had a double inducement to stay inside.
Those kids of earlier times were watched more than they realized but people didn't forbid the kids to be kids as now;plus the perverts knew the real adults were watching ,too.And nobody was taking seriously any crap psychologist when a pervert tried his stuff.
True, we didn't have air conditioning until I was in high school (and only window units then, which were used mostly at night in the DC heat and humidity.
Still, with my sinuses, I thank goodness for airconditioning. I couldn't get over it not being available in Seattle and am thankful for central air here in Iowa.
I'm also such a nerd, I went to the air conditioning exhibit at the National Building Museum. Most of the US would be unproductive w/o air conditoning. Kinda like France.