Slapping a girl across the face isn’t just about hurting her, it’s a kind of neg. It says, “I can crush you like an insect, but you aren’t worth the effort.” It’s a tacit acknowledgment that she’s weaker than you, beneath you, and if she crosses you again, you’ll put her in the hospital. You treat her like she’s a child throwing a temper tantrum, not an equal.
Like I said already, you should NOT hit women, not unless you want to end up in jail. But the principle still stands. Women should be terrorized by their men; it’s the only thing that makes them behave better than chimps.