High walls imply defensiveness, and thus implicit hostility; they announce the owner’s intent to keep others out regardless of their intentions. A low wall, like this one, says something different and more hopeful. Being only a symbolic barrier, it implies a society where people are friendly and peaceable – where common courtesy and the rule of law suffice to convince people to respect others.
Image credit: mike138, released under CC BY-ND 2.0 license