I do realize that no amount of research will change some of your minds ; just wanted to enlighten you.
Some points from the article:
The odds of a child being more aggressive at age 5 increased by 50% if he had been spanked more than twice in the month.
...her team accounted for varying levels of natural aggression in children, suggesting, she says, that "it's not just that children who are more aggressive are more likely to be spanked."
...spanking sets up a loop of bad behavior. Corporal punishment instills fear rather than understanding. Even if children stop tantrums when spanked, that doesn't mean they get why they shouldn't have been acting up in the first place. What's more, spanking sets a bad example, teaching children that aggressive behavior is a solution to their parents' problems.
The American Academy of Pediatrics (AAP) does not endorse spanking under any circumstance.