By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) - Are children who are spanked when they misbehave more likely to be anxious and aggressive than children who are disciplined in non-physical ways? Here is what we know.

Researchers studied six different cultures that had vastly different ways of disciplining children. In all cases, children disciplined by physical means, like spanking, were more aggressive. But in countries where the use of physical discipline was more common, being physically disciplined more frequently was not related as strongly to aggression and anxiety as it was in countries where physical discipline was less frequently used.

The study had looked at cultures from Thailand to Kenya and they had no findings as to whether being physically disciplined more frequently causes an increase in aggression and anxiety, or whether children who are already aggressive and anxious are simply physically disciplined more often.