The important difference between "jerk" and "asshole" is that "asshole" goes through glass. If you're driving around, then somebody cuts you off, and you mouth "jerk" at them through the windshield, they will smile at you and and wave. While "asshole" will be totally and universally unambiguously understood.

> "asshole" goes through glass

This is a great hard and fast rule of thumb for photocopiers as well!