Spankings and Learned Agression

I came across this article on the CBS News website about the relevance between spankings and aggression and anxiety in children in different cultural settings. The studies showed that children receiving spankings in countries where physical punishments were frowned upon seemed to act more aggressively than children in other countries. 336 mothers were asked questions about both their physical and verbal disciplining habits, and their children were asked a series of questions to determine how aggressive they were. In Kenya, spankings were used both at home and in school, so children interpreted it as a normal thing. Children in Thailand, on the other hand, were raised in a non-violent Buddhist environment where spankings were rare, so they were more likely to see themselves as being "bad kids". In the United States, it was a bit more difficult to put a correlation on spanking-related aggression in kids.
Whether or not spankings actually take part in aggression and anxiety, this research wasn't necessarily the most effective method of getting information. The mothers and kids interviewed may not of been completely honest about their lifestyles. Also, other factors could lead to aggression and anxiety as well.
http://www.cbsnews.com/stories/2005/11/14/health/webmd/main1042550.shtml