Absolute BS because they don’t distinguish between occasional moderate spanking and out and out beating. We spanked out daughter probably less than 10 times before she turned 8 (never needed to after that). Today at 15 she’s one of the wisest, kindest kids I’ve ever met. And if she’s a little “agressive,” then great!
When I read the article, it did differentiate between parents that spank occasionally and those that spank often. It also took into account other factors such as neglect, stress, etc.