Possibly the most consistent argument one is faced with when discussing politically incorrect subjects is the knee-jerkingly reflexive, "You can't generalize like that!" This is usually followed with an anecdote about someone's friend 

Any logical person will soon realize that when discussing macro-issues in regard to society and its trends, not only can you generalize but in fact you must generalize. 

Condensed from here  

I take it that when you see consistent behavior in group that it is obligatory to generalize even though you know there are exceptions.