I lived in Atherton, CA for a while (granted, one of the richest and safest [1] ZIP codes in the US) and we never locked our house. In fact, I did not even have keys!
I was once walking through Atherton and a police officer stopped me to make sure I wasn't doing anything suspicious. I suppose the number of "walking while white" infractions a community tallies might be a good (if unfortunate) indication of how wealthy they really are.
The same police officer later bought me a coffee for no particular reason. What a country.
The wealthy people may send their kids to private schools. The public schools may have students from working class families in adjacent areas in the same school district.
Part of Atherton is in the Menlo Park School District and part of it is in the Redwood City School District. The former is considered to be much better than the latter.
[1] https://www.buzzfeed.com/copyranter/police-blotter-reports-f...