A guy new to the block was unloading his truck when Bob, one of the other neighbors went over to welcome him to the neighborhood. After exchanging names, Bob asked the new guy what he does for a living.
"I'm a professor at the college. I teach "Deductive Reasoning," he answered.
"Deductive reasoning? What's that?" Bob asked.
The professor said, "It would be easier to demonstrate. Just answer my questions either yes or no."
"Do you have a doghouse?"
Bob replied, "yes."
"Then I can deduce that you have a dog. Is that true Bob?"
"Yes."
"Then I can deduce that you probably have a family. Is this true?"
"Yes."
"So since you have a family, I can deduce you probably have kids. Is that true Bob?"
"Yes."
"And since you have kids, I can deduce that you are heterosexual. Is this true?"
"Of course it is!" Bob replied.
"There you go Bob. Deductive reasoning. I asked you if you had a doghouse and eventually deduced that you are heterosexual. Cool eh?"
Bob said, "WOW. That is real cool!"

After that Bob heads back to the house when another neighbor, Joe stops him and asks about his conversation with the new neighbor.
"He's a professor of Deductive Reasoning at the college," Bob told Joe.
Of course Joe has no idea what Deductive reasoning is, so Bob offers to demonstrate.
"Just answer my questions yes or no," Bob instructed Joe.
"OK, first question. Do you have a doghouse?"
"No."
"Homo."