Spanking is linked to adverse physical, psychological, and behavioral outcomes
psypost.org
psypost.org
My mom and dad grew up when corporal punishment in schools was still a thing. They both separately lived in Britain and West Germany before moving to the US. My dad also grew-up in the Philippines for a few years.
I was beat about a dozen times by my parents, but never by private or public school officials. Later, my parents made me write sentences on paper like Bart Simpson on the chalkboard. Haha.
Interestingly, corporal punishment is still allowed in the public schools of 14 US states and private schools of 48. Boys receive 81% of corporal punishment while girls received 19. African-American boys receive 16x more than white girls. Technically, this violates Title VI, Title IX, and Section 504 (but sexism only applies to girls, after all and racism doesn't exist if it involves abuse or the school-to-prison pipeline).
https://en.wikipedia.org/wiki/School_corporal_punishment_in_...
These days, I think US parents are both too busy trying to make money at work to teach their children to behave properly, empathize with others considering the Golden Rule, have manners/be considerate/respectful, fearful and inexperienced in the world when their parents are around because of limitation imposed by helicopter parenting, and generally grow-up more "feral" because of unsupervised "latch-key" alone time, and narcissistic because of the celebrity and materialistic culture without the parents to counter it. Also, I think modern parents aren't as skilled in correcting behavioral problems, don't impose consequences as much, and aren't as concerned with their children being unruly in public.