SBR cast members mentally challenged?

I am asking a very serious question because someone I know likes to watch South Beach Tow and I cannot discern if all of the members of the cast are really, in real-life fact, mentally challenged or just acting to a script. If the cast is acting to a proscribed script then shame on the producers. If the cast members really are mentally handicapped then shame on the producers.

I have painfully endured half a dozen episodes of this show in order to form an honest opinion of the show.

This program represents everything that is wrong with America today. This show glorifies ignorance, stupidity, spite, hatefulness, arrogance, violence, lack of judgment, lack of morality, lack of common decency, and many other despicable failings.

Is it any wonder that the rest of the world thinks that America is a morally bankrupt society? Shows of this genre provide proof to those people around the world that America is, in fact, a morally bankrupt, brain-dead, society.

So my question stands. Are the cast members REALLY mentally deficient, or are they just normal actors who are doing their job well and acting out the absolutely hateful, despicable, characteristics of American society. If they are normal people who are just acting out a script then they are amazing actors because this show makes me ashamed to be an American citizen.

I just want to know the truth.