Greeting is a Learned Skill

Dogs are not born knowing how to interact politely with strangers. Some dogs love everyone and jump on them. Others fear everyone and bark at them. Both extremes need training.

Forcing a fearful dog to accept petting from strangers is called flooding, and it makes fear worse, not better. The dog endures the experience but stores it as threatening. Over time, the fear builds until the dog stops enduring and starts snapping.