Clutter
In another study performed in Lowell, Massachusetts, researchers found that cleaning up the physical environment was more effective at reducing crime than putting more police on the street.
Both studies are consistent with the “broken windows theory” proposed by social scientists James Wilson and George L. Kelling in 1982 in the Atlantic Monthly.
The basic premise is that if the physical environment is clean or orderly, then people will behave in more orderly ways.