Causation vs Association

One of the biggest mistakes in Statistics is confusing Causation with Association.

We can say that cigarette smoking causes lung cancer but we can not say stop smoking causes weight gain. Yes, it is true most subjects will gain weight when they stop smoking. There is an association, but no causation.

One of the best examples is when there is more ice cream sold at the beach, there are more drownings. Does this mean that eating ice cream causes the drownings ? NO !! There is an association between ice cream selling and drowning, but NO causation.

The reason there is more drowning is because there are just more people at the beach. The warmer the weather the more people go swimming the ice cream truck shows up to make some money. This is sometimes called the confounding variable or lurking variable.

There was a very important report recently that there were more Shark attacks in Florida, and therefore more dangerous to go swimming. Well this is not necessarily true.

People wanted to know why the sharks were all a sudden attacking people. Was this JAWS revenge ?

NO, it just turns out that there are MORE people swimming in the ocean, where the sharks just happen to live. It is usually the people running INTO the poor shark, not the other way around.

The key in statistics is to find that confounding variable.

Another interesting stat is that people who have more books at home, their children are more likely to succeed in school. Does having those books at home make kids smarter ? Can a family go out and buy a library and all of a sudden their children will be brighter ? NO !! (although I have met families that have tried doing just this...maybe more for show then to help their children's gpa...lol)

I have a few family friends that have the Steven Hawkins book "A Short History of Time". The author claims anyone with an education should be able to read it. I have tried several times with no success and i have read Singh's Big Bang which is three times as big. So i have found this book at my friend's home library. It probable sat on the coffee table for a year or two (when the book was popular and Steven was making the book tour in his wheel chair....he is considered to be one of the brightest man alive). So i have taped a $20 bill to one of the back pages of the book, to see if anyone ever actually tries to READ the book. Every year i check this book in the home shelves and the $20's are still there....lol