Again, I need to interject...from a standpoint of the use of the word "empathy".
To state "people without empathy turn into predators is absolutely not true and unfounded." This word has been exploited to the hilt and gives a wrong impression when used such as stated above. Can you imagine if you should learn that your neighbor has an teen without empathy as they may have Aspergers and the entire neighborhood fears that she will turn into a predator?
And yes, this is from a personal standpoint. I've written about this over and again. One of my purposes in this thread, after discovering how much the word is being used, was to help keep the posters educated on the proper usage of the word as to alleviate misconceptions of those who lack or do not have empathy in sentences such as above. Apparently my goal is failing. Let me clarify. Not all people who lack empathy are going to be sociopathic, destructive, or a Casey Anthony.
Remember, there are those who are born without the ability to empathize (such as those with autism spectrum disorders) and it is unfair to state they will turn into predators. Nor, in my opinion, is the most destructive "is the lack of empathy".
In my personal opinion the most destructive are those who lack conscience, moral goodness and self control.
This is a pretty good article that basically asks the question: Why do autistics have a sense of morality while psychopaths do not, given that they both display a deficit of empathy? (ASD=autism spectrum disorder)
http://fvignemont.googlepages.com/Autism_Morality_Empathy.doc.