Logic - "Because I said so! Thats why!" Farm-Life - "Your room looks like a Pig Pen!" Envy - "There are million's of less fortunate children in this world who would LOVE to have broccoli for dinner like you do!" Anticipation - "Just you wait till your father gets home!" Value of Education - "If you don't do well in school, you'll end up living under a bridge!" Medical Science - "If you keep making that face, it will stick like that!" Time Travel - "I'm going to knock you into the middle of next week!" Foresight - "Wear clean underwear, what if you're in an accident?" Hypocricy - "If I told you once, I've told you a million times..." To Think Ahead - "If you don't pass your spelling test, you'll never get a good job!" Receiving - "You are going to get it when you get home!" Wisdom - "When you are my age, you'll understand." Ophthalmology - "If you sit that close to the TV you'll go blind!" More Logic - "If you fall out of that tree and break your neck, you're not going to the store with me." ESP - "Put your mittens on! I know when your cold!" Take On a Challenge - "What were you thinking? Answer me when I talk to you! Don't talk back to me!" Sex - “How do you think you got here?” Adulthood - "If you don't eat your vegetables, you'll never grow up." Appreciate a Job Well-Done - "If you're going to kill each other, do it outside - I just cleaned!" Humor - "When that lawn mower cuts off your feet, don't come running to me!" Osmosis - "Shut your mouth and eat your supper!" Religion - "You better pray that will come out of the carpet!" Weather - "Look at this room!! It looks like a Tornado went through here!" Irony - "Keep crying, and I'll give you something to cry about!" Roots - "Shut the Door!! Do you think you were born in a barn?" Contortionism - "Will you look at that dirt behind your ears!" Behavior Modification - "Stop acting like your father!" JUSTICE - "One day you'll have kids, and I hope they turn out just like you!"
I didn't come up with all of these on my own, several are widely spread online, so I don't know where they originated.