Cum Hoc Ergo Propter Hoc · 4:12am Dec 24th, 2012
Cum Hoc Ergo Propter Hoc
When Event A occurs, Event B will also always occur, therefore Event A causes Event B.
Example A:
Lojika McPhallussy: The number of people infected with AIDS has increased at the same time the number of people using the internet has also increased. This must mean that using the internet is somehow tied to the transmission of AIDS.
Ida Praposar: Maybe AIDS caused people to start using the internet?
Example B:
Ida Praposar: A study has shown that most car accidents occur in within five miles of the home.
Lojika McPhallussy: Wow, the roads near houses must be really unsafe! or possibly car accidents make people want to build homes nearby!
Ida Praposar: No, people can be found at home, or around their homes more often than in random locations, which means accidents that have the same probability of occurring anywhere would logically have more occurrences in places where they spend more time.
Cum hoc, ergo propter hoc translates to "with this, therefore because of this", and is also known as "correlation does not imply causation". Three guesses as to why I used the Latin name instead. :B
Another extremely similar fallacy exists, called post hoc, ergo propter hoc (translating to "after this, therefore because of this"—confusingly, it is also known as correlation does not imply causation). The difference is that events must occur simultaneously for cum hoc, while for post hoc, the events must occur in a chronological order, and the event that occurred first is assumed to cause subsequent events. It's probably easier (and less pretentious) to just refer to any faulty cause fallacy as correlation does not imply causation. This fallacy is commonly used to misread or misinterpret statistics or to imply a false cause for something irrelevant.
I once read a completely serious newspaper article that correlated higher suicide rates to places where people listened to a lot of country music. It may be logical to assume that two events that always occur around the same are related, but you know what they say about assuming. Plus, to assert that one is the cause of another would be an even larger leap. If there is information, it isn't always the best course of action to assume there is nothing outside of what was given, to make connections with only the data that was presented.
I like your blogs. They fill me with logic.
"Twenty-seven lawyers in the room. Anybody know post hoc ergo propter hoc? Josh?"
"Uh, uh, post - after, after hoc, ergo - therefore, after hoc, therefore something else hoc."
"Thank you. Next?"
"Well, if I had gotten more credit on the 443..."
"Leo?"
"After it therefore because of it."
"After it therefore because of it. It means one thing follows the other, therefore it was caused by the other. But it's not always true. In fact, it's hardly ever true."
I love The West Wing.
As the total number of pirates decreases, the average global temperature increases...
Sometimes both cum hoc and post hoc are just coincidences, but sometimes they're not; there may be a very strong correlation. But it's important to always look for a missing common cause, too.
For example, the thing about suicide rates related to country music. I'm not saying this IS the case, but as an example, it could be that what we're looking at is "low-income areas with a mostly white population", which are both country music consumers and have a high suicide rate. Those two facts are not really related to each other; they're just both aspects of a specific population's lifestyle.
This is what I always get annoyed with when the "violent video games cause violence" thing comes up. I would assume that people who have violent tendencies and have trouble controlling their behavior would be heavy consumers of games that give them an outlet for that and 'angry' music that puts a voice to what they're feeling. That doesn't mean the games or music cause violence, and people who are otherwise peaceful can certainly enjoy them without being ticking time-bombs.