Correlation and Causation – DMB III

For most of my academic career, I was all set up to excel in Psychiatry. I took the hard math and science classes, right along with my more artsy-fartsy classes. It likely surprises none of you that I’ve been a published writer (don’t get too excited, just poetry and short stories), and English and I always got along well. If I could have taken only English classes, I probably would have just done that.

It took a very perceptive and gentle professor to make me realize that my mental block in regards to pedophiles would make my intended career nearly impossible. (By “mental block” I mean a seething, completely irrational hatred. I’d been trained, logically, to understand their actions and motivations. Logic and pedophilia just couldn’t go together for me.) Working in forensics wasn’t to be in my future.

So from forensic psychiatry to research psychiatry I shifted. (Don’t ask how I ended up in Marketing/Graphic Design. It’s a long winding road my friends.)

Despite my love of all things art, science and math hold an interest for me too. (Although math stops being fun for me when numbers are no longer “real.”)

With science I was always fascinated by biology. By the questions regarding whether a person is born with every aspect of themselves encoded in their very cells…or whether their upbringing decides who they will become. (Personally, I always felt like it was a little bit of everything.) MFH still finds the occasional Punnett square sketching when I’m trying to work out proper chances of inheritance. (Yes, he thinks it’s very weird.)

With Math, my absolute favorite subject is statistics. I loved how simple it was to change the way people answered a survey just by adding or changing a few words in the questions.  It made me realize how skewed some surveys are and how unreliable they can be. It also made me keenly aware of the difference between Causation and Correlation.

You know when you hear all these studies about researchers finding “links” between this and that? Autism is an especially hot button topic at the moment, so I’m going to talk about that. There’s a lot of money being thrown at researchers to find a cause for Autism. There’s also a disgustingly high increase of online readership for any “news article” that posts about something linking to Autism. Let me be clear here that I completely understand the desire of the average person to read about a disorder that we really still know so little about. That’s not what I find disgusting. What I find disgusting is that certain “news sources” chose to release bad, poorly researched studies as facts, knowing it will drive readership to their pages.

But I’m getting ahead of myself here…

One study I’ve been following – and will continue to follow as it progresses through primate testing – shows that excessive exposure to ultrasound waves alters brain development (in mice). There is nothing being claimed here about Autism, but it was mentioned as a disorder that is centered in the brain. They are trying to see if excessive ultrasound use actually cause neurological disorders, or if the current “link” is simply a correlation involving other factors.

Lemme explain.

On one of my Statistics midterms we had this question regarding a study. The study showed a link between ice cream consumption and colds/flu. The less ice cream consumed, the more colds/flu. The question was, why isn’t there a causation between not eating ice cream and getting a cold/flu?

At first I had the same reaction I had when learning about weighted statistics. (Just because something only has two outcomes doesn’t mean there is a 50-50% chance. Airplanes don’t crash 50% of the time and land safely 50% of the time, for instance.) I didn’t really get it. I had a fleeting moment of wondering if a lower calcium intake had anything to do with a person’s likelihood of getting sick.

Then I noticed something. The graph showing this “link” between the two had an additional line of data showing the months of the year. It showed that the colder the month, the less ice cream consumption…and the more colds/flu. People weren’t getting sick because they weren’t eating ice cream…they were getting sick because the lower temperatures were effecting their immunity.

It’s a really simple, silly example, but you can clearly see that correlation between two things does not equal causation.


That’s part of the reason why I ignore a lot of hot topic research studies. Or, if not ignore outright, at least file into the column of “let’s see if anyone can repeat these outcomes,” before we get all crazy.

Such as in the case of Andrew Wakefield (and, man, do I feel like I’m opening a can of worms here), whose 1998 paper claiming that MMR vaccinations caused bowel issues and Autism was never able to be repeated in a lab setting. (I’m being very good here, not talking about all the other reasons Wakefield and this entire situation drives me bonkers.)

If a single scientist cannot recreate your work, one of two things happened. It is possible, and has happened in very rare cases, that the results were “fluke.” There was no malintent, just an odd outcome, never to be repeated. The more likely, though, is falsified data. This last makes me so angry, because falsified data not only turns the media into salivating monsters of misinformation, it also gives some people false hope. If someone is really sick, and some jerk releases a falsified study showing something random will cure their sickness…well, you get the picture.

I’ve talked ad nauseam about informed decision making, so I’m not going to bring it up again. I am, however, going to say that our world has become a massive influx of often instantaneous information. The thing to remember is that not all information can be treated equal.

Is it my job to force my opinion on…lets say vaccinations…onto others? No, it is not. If someone asks my opinion, I’ll give it. I may have to bite a hole in my lip to keep quiet, but I will not berate a mother for having a differing opinion. But when someone does not show me the same respect and attacks my decision making skills, you better believe that I will pull out my arsenal of facts and figures and use them to full effect.

[I will disclaimer here that if I see a mother actually harming her child, all bets are off. I am not quiet in defense of others.]

When did mothering become a death match competition where only you are doing it the right way and all other options are just WRONG, WRONG, WRONG?

It’s exhausting to try and navigate the waters of parenting. To figure out how to be supportive without smothering. To encourage without creating unrealistic expectations. Most of this seems to be worked out on the fly, with not enough sleep to safely brew a cup of coffee – let alone raise a human being.

So to anyone out there who has rolled their eyes at my choices, or more directly had it out with me over something I am or aren’t doing, relax. You’re still the best mommy in your own mind. I’m going to do everything in my power; read every study, scour conspiracy theories, and – shocker here – talk to actual mothers who I think have pretty great kids; to be the best mom I think I can be.

But you know what the funniest part of this whole thing is? Despite all my faith in stone cold research, sometimes I really do think you just have to go with your gut. After all, that’s where the babies come from. :p