Friday, February 1, 2013

Post Hoc As Applied To Everything

I was explaining to my writing class this week what the “post hoc” fallacy is.  A quick flashback to philosophy class reminds us that just because one event precedes another, the first does not necessarily cause the second.  Correlation does not equal causation.  (Stick with me, this will get more interesting.)  Gerald Bracey’s got an awesome book called Reading Educational Research: How To Avoid Getting Statistically Snookered that lays out how to read data (think pie charts, graphs, tables) accurately and not get snookered by all those hacks out there wanting to convince you of things that are partially true but not really. 

When I was in college and hadn’t yet gotten my results from my Math CLEP test, I was enrolled in the basic science class in case I had to meet the math/science requirement that way.  (I went to a small Christian college that had such things as a 3 credit math/science requirement because we were super busy reading the Bible and stuff.)  The first experiment we did in that science class involved developing a hypothesis about how popcorn is popped in an air popper.  I didn’t really get the point of the assignment because we all clearly knew the answer.  But I diligently followed the scientific process and came up with my hypothesis:  The popping sound is what makes the corn pop.  After all, you hear the sound, and then the popped kernel comes tumbling over the edge and into the bowl.  My professor was not amused at my smart-ass, post hoc hypothesis.  I think her molecules were all in a bundle because based on my observational data, we weren’t able to disprove my hypothesis.  I think we all learned something.  About 3 weeks into the class, I found out that I passed the Math CLEP and dropped the class.  My professor smirked and hummed while she signed my drop slip. 

When you find yourself 9 months pregnant and ready for that baby to just. come. out. already, you get all sorts of amazing advice from other moms.  Pineapple!  Walking!  Sex!  Rasberry leaf tea!  These are some of the standard tips that may actually have some evidence behind them.  But then you hear things like spicy food! and bounce up and down! and this-one-very-specific-thing-I-was-doing-immediately-before-I-went-into-labor!  Classic post hoc.  For me, my labors are evidently induced by watching Wipeout.  I was watching people get smashed in the face with large objects covered in dense foam, and bam, Eden was born 12 hours later.  Two years later almost to the day, I was watching people get knocked off of tall objects into pits filled with white foamy substance, and bam, Isaac was born 5 hours later.  Good night, and Big Balls worked for me. 

When I hear my children fighting in the other room, and one of them comes running to me and says, “He hit me!” and the other one is in a puddle on the floor crying, well, it’s anybody’s guess.  With siblings, there’s a whole lot of correlation and causation.  I tend to go into post hoc mode and try to determine who did what to whom and when and find the initial burst of inertia that started the whole thing.  It’s futile, really.  Children are impressive illustrations of the post hoc fallacy.  There is always an endless chain of previous causes (“He hit me!” “She took my toy!” “But he wouldn’t share!” “But I just got it!”  “But I never get to play with it!” and I could seriously go on all day), or some other cause, or no cause. 

Isaac is LOVING this post hoc fallacy right now.  Last week, when we were almost done grocery shopping, Isaac was getting antsy and wanted out of the cart.  I clearly explained that if he listened well, he could get down, but if he didn’t listen to my instructions he would have to get back in the cart.  He appeared to agree.  Next thing I know he’s climbing on a counter underneath a sign that clearly says, “No climbing on the counter.”  I get him off the counter, tell him no climbing on the counter, remind him that he needs to listen or he will have to get back in the cart.  He appears to agree again.  Next thing I know he’s climbing on the counter again.  I pick him up, he throws a fit, I wrangle tantruming toddler to the car along with grocery cart and big sister.  After things are calmed down, we have this conversation: 

Me:  “Isaac, you cannot scream in the store.  It hurts people’s ears.  I put you in the cart because you did not listen and you got on the counter after I told you not to.”  (This is me trying to establish causation.)
Isaac:  “But, my whole body wadn’t on da counter.”  (This is Isaac insinuating that I am committing a logical fallacy because my data is not entirely accurate.)
Me:  “True, you were climbing on the counter.  Your hands and torso and one knee were on the counter.  I told you not to get on the counter and parts of your body were on the counter, so I put you in the cart.”  (This is me reiterating causation and clarifying the facts.)
Isaac: “But, the last time we went to dis store, Eden wad climbing on da counter.  I just doing what Eden did before.”  (This is Isaac saying “Post hoc!  Post hoc!”)
Me:  “Yes, but you need to follow the rule even if no one else is following the rule.  I put you in the cart because you didn’t listen to the rule.”  (This is me engaging the crazy and asking myself if I’m seriously having this conversation with my 2-year-old.)
Isaac:  Silence. 

I do not take this silence to be agreement.  I am not so easily fooled.

I am seriously in trouble.    


Anonymous said...

I love this!

-your bro

Jamie said...

Thanks, bro! :)