Some say that "abusers" abuse because "they can". Some say it is about control. I agree with both of these assessments, but I also believe there is a deeper, underlying cause.
To say that "abusers" abuse "because they can", is partly true; for we all have free will to pursue what we deem necessary for our survival. In that sense, we ALL do whatever we do..."because we can".
Additionally, although I agree that "abuse" tends to be about "control", I again think this is only partly true; because every human being that is striving to make progress in their lives -- both abuser and non-abuser -- is also striving to exercise some measure of "control" over ourselves and our environment.
So, then, if the abuser and the non-abuser are both seeking to do what "they can" to maintain a certain level of "control" over their lives and their circumstances, what makes the abuser "abusive" in his or her attempts, as opposed to the "non-abuser"?