When I took out all the fancy PhD words this was what I got. The author will counter the Bible because modern science says it is so. Pretty lame excuse.
PS-We've never wanted or needed to spank our child but there are PLENTY of people who are not as fortunate.
This puts it in a nutshell. You can choose to believe the word of God in the Bible, along with the experience of parents over thousands of years, or you can choose to believe the latest "study" that will be contradicted by another study next week. Anyone who tries to use "scientific studies" as the guide to raising children will be in for a big shock, and their poor unfortunate children will be in for a wild ride as the parents change their minds every week based on the latest data to be released.