The problem with this study making the rounds is that it assumes that spanking is supposed to generate obedience. Who wants to raise children who are obedient? What we want to raise is children who are self-sufficient and who don't cause us problems. They are children who learn to deal with power structures and pursue their own interests accordingly.
Which is exactly what the study says spanked children are like. They are capable of wielding deception, they are capable of wielding violence in their own interests, and they are capable of pretending to go-along-and-get-along when they aren't in positions of power.
They're Odysseus, in other words.
This is the matter of Plato's Hippias Minor, which treats the question of whether Odysseus or Achilles was the greater hero. The usual position of historians and philosophers is that this is a very unimportant dialogue, with a silly argument, that we might even doubt was Platonic except that Aristotle confirms that Plato wrote it.
That's not right at all. The point is that Plato was teaching the Athens that killed him that Socrates was a kind of Odysseus. Aristotle takes the 'simple' reductio argument of this dialogue seriously enough that he responds to it in the Nicomachean Ethics. This is very serious stuff.
What kind of a child are you trying to raise? An obedient one? Or Odysseus?