During Act II, one of the parts that I thought was most revealing about Iago's character was his discussion with Desdemona about different types of women. Not only were his opinions degrading, but they also showed how he chose to view the worst in all types of people. When he sarcastically described the perfect woman in lines 147-157, it becomes apparent that he doesn't believe a woman like this to actually exist in real life. Unsurprisingly, he has a jaded few of those around him and is borderline cruel to his wife Emilia. When she says "You shall not write my praise", meaning "You don't have anything good to say about me", he answers "No, let me not" (II.i.115-116). By bluntly refusing to compliment his wife, Iago reveals that he does not think highly of his her in any aspect.
Then Desdemona presents him with four scenarios involving women. She inquires him on how he would compliment a smart and beautiful woman, and he answers that if a woman is pretty and smart she uses her looks to get what she wants. Next, she asks him about a smart and unattractive woman. Othello asserts that even if a woman is ugly she will be smart enough to find a guy who will sleep with her. Gee, negative much?
When she asks him about dumb and beautiful women, he compliments these most kindly saying that no pretty woman is stupid because her stupidity generally makes her more attractive to men. He seems pretty biased if you ask me. In terms of dumb and ugly women, Iago says that no matter how ugly or stupid the woman is she plays the same "dirty tricks" that smart and pretty women do. Desdemona didn't seem to appreciate this argument of his very much.