lowers IQ . . . really?

I think it depends on the type of you get. For sure, getting slapped across the face and yelled at, all at the same time, is different from a parent explaining what you did wrong and explaining the consequences of your actions and then ing you and hugging you afterward and telling you they still love you. "" has unfortunately come to mean "beating" which I'm sure comes from people with lower IQ's to begin with. I have seen mothers in Wal-Mart yell at their kid to shut up and then smack them around. Perhaps this is what the article refers to.