Man approaches to greet a new neighbor who is just moving into the house next door and asks what he does for a living.

Neighbor 1: "I am a professor at the University, I teach deductive reasoning"

Man: "Deductive reasoning, what is that?"

Neighbor 1: "Let me give you and example. I see you have a dog house out back. By that I deduce that you have a dog."

Man: "That is right"

Neighbor 1: "The fact that you have a dog, leads me to deduce that you have a family"

Man: "Right again"

Neighbor 1: "Since you have a family I deduce that you have a wife"

Man: "Correct"

Neighbor 1: "And since you have a wife I can deduce that you are heterosexual."

Man: "Yup"

Neighbor 1: "That is deductive reasoning"

Man: "Cool"

Later that same day...:

Man: "Hey I was talking to that new guy who moved in next door"

Neighbor 2: "Is he a nice guy "

Man: "Yes, and he has an interesting job"

Neighbor 2: "Oh, yeah what does he do "

Man: "He is a professor of deductive reasoning at the University"

Neighbor 2: "Deductive reasoning, what is that?"

Man: "Let me give you an example. Do you have a dog house?"

Neighbor 2: "No"

Man: "Fag."