There's probably something to this. I don't have kids so luckily I don't have to think much about it (yet, at least). While there are plenty of studies about psychological issues from spanking, but I've always been uncomfortable about the definitions. There is a fair difference between a single sharp smack on the butt (clothed, not bare) like I and my siblings, friends etc. used to get (and deserve) as kids, and actual abuse (i.e. beatings, using implements, hits to the face, arms, torso, etc.), but I feel like most of the studies lump them in together.
It's also hard to control for whether it's a single spank for discipline used only when the situation warrants it or routine, arbitrary or random spanking. There's probably going to be psychological abuse or neglect coming along with it if it's the latter but far less likely for the former.
I have children (too young for this to matter yet) and I have the same discomfort. I was 'smacked' on the bottom sometimes as a child - no real idea about the frequency as this would now be a long time ago. Small children don't have the same sense of reasoning / looking forward as e.g. teenagers or adults, so I appreciate something more primeval should work better (and I'm not going to take away their food). But while all the data suggests hitting or spanking a child is bad, there seems to be no mentions of discriminating between genuinely physically harming the child (e.g. lasting damage like a bruise) and something which hurts but has zero long or medium-term physical effect - just a temporary stinging of the skin over a heavily muscled or fatty area like the bottom.
My personal feeling is that if researched well, the data would probably show that in small children, some form of physical punishment would be shown to be effective and leave no lasting psycological issues. I just don't think there's any good evidence either way.
I promise there not only has been research on small children and corporal punishment and that it's not at all effective and that it is damaging. Above I linked to an article on the subject by the APA. Here's a link to the meta-analysis referenced in the article: https://link.springer.com/article/10.1007/s10567-005-2340-z
"The results indicated that effect sizes significantly favored conditional spanking over 10 of 13 alternative disciplinary tactics for reducing child noncompliance or antisocial behavior. Customary physical punishment yielded effect sizes equal to alternative tactics, except for one large study favoring physical punishment. Only overly severe or predominant use of physical punishment compared unfavorably with alternative disciplinary tactics."
In short:
conditional spanking - more effective that 10/13 other disciplining methods
customary spanking - no more or less effective than other disciplining methods
severe / predominant use of spanking - worse than other methods
The rest of the material available without access to the full paper just seems to back the assertion that data is poor on this topic, and there are methodological issues that make it hard to assess different levels of physical punishment seperately.
My bad. I usually try not to do _exactly the thing I did_, rage-pasting a link without reading it fully.
I'm not going to get into a deep back and forth over this, but nothing I am aware of shows spanking of any sort has good long term effects on behavior and pretty much every piece of literature out there points to corporal punishment being effective for getting a kid to cease acting out, but either ineffective or worse for long term behavior changes.
And sure, maybe being super calm and measured with your application of corporal punishment will prevent it from doing damage. Just seems like a strange path to take when there are effective ones out there that don't require violence or the threat of violence against children.
My mom and dad use to hit me in the bottons witha flip flop as a last resort.
Usually the first measure would she put me staring the wall for a few minutes. To a children that was horrible since I was really bored with the punishment.
In more than one occasion she forget that I was in the "thinking corner" and found me sleeping on my feed, suported by my face in the wall.
I have kids and don't smack them. I don't really feel like I am lacking a tool in my arsenal of discipline. Usually time out, withholding things like TV or treats is enough.
It's also hard to control for whether it's a single spank for discipline used only when the situation warrants it or routine, arbitrary or random spanking. There's probably going to be psychological abuse or neglect coming along with it if it's the latter but far less likely for the former.