I was smacked routinely - if I cried I got smacked again "I'll give you something to cry about". I don't think it affected me, I was quite a violent little girl, but I was an absolute tomboy so used to love wrestling & a good fight. I actually felt pampered compared to my peers as many were hit with belts, twin tub sticks etc, whereas my mum only ever used her hand.
With my own kids, different times, different place, I can count on the fingers of one hand the times I smacked my 2 boys (combined).It wasn't acceptable & most mums didn't smack. My second was maddening & made me grind my teeth, I got a "Timmy Mallett" inflatable hammer & used to hit him over the head with it (when he was 8, 9 yrs old) it was a laugh for him & we both used to end up giggling, but it did relieve my feelings! & maybe that's because I'd been smacked so much myself. I welcome this, it's been a grey area for years, making it illegal clarifies things for parents - just don't!