This thread should be a prime example to all the challenges in logic, reason, and ethics we face as libertarians. There is one side clearly being illogical, irrational, and supporting immoral acts...all in the name of tradition, social acceptance, religion (the 'spare the rod' crap isn't even in the Bible...it's dated to like 1600 years later), not facing the ego, etc., etc., etc. I feel so bad for the kids some of your raise(d). I feel even worse for all of us who have to deal with them when they leave your homes for the rest of the world. Children aren't like dogs...you can't beat them and it only be your problem forever. Kids eventually get let out of the yard, and eventually when the sample size is large enough, all the negative statistical effects on their lives and the lives of others come into play. It may not be the majority of spanked kids, but nonetheless the rate of cancer is increased for them, the rate of domestic violence victimization or victimizing goes up, the rate of promiscuity goes up, the rate of drug abuse and addiction, the rate of obesity goes up, the rate of violence goes up overall, the rate of incarceration, etc., etc., etc.
You have failed as a parent if you have learned how to give your children the best possible statistical chance of success and happiness in life, and refuse to give it to them when you can. It matters not whether your kid ends up the bad stat...it takes 100,000 of them for a 3% rate to appear with any reliability. As the sample size grows, the stats becomes more reliable...and we have billions of kids to look at for evidence. If you parented correctly, your kids success or failure has no connection to those risks, as you limited them as much as possible. It doesn't mean a spanked kid won't be immune from all those downfalls, and it doesn't mean a non-spanked kid will never suffer any of those downfalls...it just means it isn't your fault when they fail and is partly to your credit when they succeed. The stats prove this factually...there is no arguing it's too small a sample size or methodologically un-reviewed. We KNOW what gives kids the best chances at survival and success...but some of you just refuse to give your kids the best chances for some illogical, irrational, and therefore ethically bankrupt reason.
Blame yourselves when little Suzy is a whore or little Johnny assaults a man in his alcoholic stupor, or whatever. Don't act like you had no part in that result. You totally had a hand in it. If that isn't the result, consider yourself really lucky...not a good parent.