Mid thirties, and was smacked fairly regularly when 2-8ish, by both parents. It was quite normal to us (and was certainly a lot better than the beltings they both got from their own parents). Never ever without reason, and rarely in anger (although dad is short fused, but mostly shouts and rants). It was very much “for your own good”, and they were very loving and involved parents, I genuinely believe that’s why they smacked us. Usually reasoned with/warned first, and smacks varied from gentle open palm over clothes (ie for stupidity, you should know better, don’t throw balls indoors and break plant pots, sort of behaviour) to stick/wooden spoon for defiance. Mum gave a few quite hard smacks on bare legs when we’d done something dangerous (and probably scared her, looking back) that might have been as much to relieve her feelings as for discipline, but certainly taught us what not to do! We were pretty well behaved, compliant children generally, and although we were occasionally threatened with a smack well into our teenage years, the threat was always enough for us to know when we were pushing our luck.
I remember other non-punishments as being much more unfair, can’t think that I was ever smacked without deserving it (and we probably got away with a lot as well). Also, we had a minute or two to stop crying, and then that was that - maybe a “and don’t do it again!” then it was all over with, hug, eyes wiped and move on. I don’t resent them at all, and have a very good and close relationship with them now, although I thought them very strict as a teenager, especially when comparing them with friends’ parents. Even at that time, though, I would have admitted that they thought all their rules and restrictions were for our own safety/good, and they were very generous and supportive in most things.