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correlation causation

Correlation implies causation – when it does or does not with vaccines

I originally wrote this article in 2014 to discuss whether correlation implies causation. Not that I expect everyone to read and remember this one article, but it’s frustrating when I see a conversation where people who deny science and accept science both misuse correlation and how it relates to causation. So, I decided to update this article and republish it as a reminder that the relationship of correlation to causation isn’t as easy as a simple trope or meme.

One of the foundations of biomedical science is whether correlation implies causation. Anti-vaccine activists often conflate or misunderstand the two, rejecting or accepting correlation as it fits its narrative.  The “correlation implies causation” story is often abused, misused and confused by many writers.

One thing we do know about correlation is that if you can’t establish correlation, despite numerous attempts, it is nearly impossible to claim causation. Also, if you do observe correlation, it also doesn’t imply causation. 

But there are methods, grounded in powerful science, to establish causation from observations of correlation. So sometimes correlation does not imply causation. But sometimes correlation implies causation. 

This article will help show how we may be able to establish causation from observations of correlation. And, like all science, this is hard stuff. Read More »Correlation implies causation – when it does or does not with vaccines

flu vaccine ingredients

Flu vaccine ingredients – not so scary using simple math

When dealing with those pushing pseudoscience, like the antivaccination cult, the most frustrating thing is that they tend to ignore and deny the most basic tenets of science. If denying the fact of gravity would further their goals of “proving” vaccines are neither effective nor safe, they would do so. And now that it’s flu season, they’re producing zombie tropes about flu vaccine ingredients.

If the antivaccination movement didn’t lead to epidemics of long-gone diseases, which can harm and kill children, the conversation would be over. I would just put the vaccine deniers in the same group as evolution deniers (creationists) or gravity deniers (there has to be some, somewhere). I would mock their pseudoscience, and move on. Of course, their denialism does lead to deaths of children, so we have to do what is right, and stop their lies, misinformation and ignorance in every forum we can.

We have to appeal to scientific values, and despite the fact that antivaccination pushers don’t share those values, we must continue to try. I have gotten enough emails and comments from people that they have started to vaccinate because of what I have written, so maybe some child’s life is better because all of us who support vaccines are heard.

Read More »Flu vaccine ingredients – not so scary using simple math

Simple math – the dose makes the poison

If you spend any amount of time on the internet researching science and pseudoscience, you’ll find alarming claims about toxic or poisonous substances in our foods, vaccines, air, water, and so much else. And then you’ll find a lot of people (myself included) who try to present science-based evidence that these substances are neither toxic nor poisonous.

Generally, the pseudoscience argument proceeds along the lines of “this unpronounceable chemical is going to cause cancer.” And the science (read scientific skeptic) side says “wrong!” Or something like that.

Paracelsus, a 16th century Swiss German physician, alchemist, astrologer, is traditionally thought to have founded the discipline of toxicology, an important branch of medicine, physiology, and pharmacology. Paracelsus wrote one of the most important principles of toxicology:

All things are poisons, for there is nothing without poisonous qualities. It is only the dose which makes a thing poison.

In other words, if you’re speaking about substances in foods or vaccines or anything, the most important principle is that the dose makes the poison (or toxin). Everything that we can consume or breathe is potentially toxic, but what is the most overriding principle must be the dose.Read More »Simple math – the dose makes the poison