To quell that storm, the following week another guest came in to talk more in depth about cancer screening but this guest then made the mistake of mentioning how many cancers can be attributed to behaviours such as obesity and smoking. In fact, the guest said, behaviours cause more cancers than environmental toxins despite host Michael Enright prodding her to say otherwise. Cue another deluge of angry letters saying that ‘isn’t it obvious that the toxins in our environment are causing pretty much all our cancer and shame on this researcher for blaming the victims of cancer instead of the big corporations spewing all these toxins!’ Whoa. That was intense.

When it comes to blaming the victim, these people have it entirely backward. Epidemiology cannot, ever, point to a person and say with certainty that their cancer was caused by x, y or z. Even if a three-pack-a-day smoker got lung cancer, there’s always the chance that something else caused the lung cancer.

What epidemiology can do is to look at two groups or people who are as similar as possible in every way except one being obese and the other not (which, especially in the case of obesity, is very difficult to do). If it turns out one group has more cancers than the other, epidemiologists can attribute it to obesity. Epidemiology can only ever tell what might affect your risk of cancer, it can never say why a particular person actually got cancer.

The only way we could ever blame a specific person for their cancer is if we went back in time, made them not obese in this case, and ran the clock forward again to see if they still got cancer. If they didn’t, then you could say their obesity, in some way, caused their cancer. We’re a long way from time travel so we’ll have to settle for the first approach I described.

What’s more is it’s clear that the public, and more than likely a good chunk of those angry listeners, do blame victims of cancers in some cases. I can’t find the data right now but which cancer charity do you hear the least about: breast, prostate or lung? Why do you think that is?

Jesse Galef of Measuring Doubt caught ESPN writer Pat Yasinkas making a classic mistake called outcome bias. Talking about the Atlanta Falcons who tried and failed on a fourth and inches attempts:

When Mike Smith first decided to go for it on fourth-and-inches in overtime, I liked the call. I thought it was gutsy and ambitious. After watching Michael Turner get stuffed, I changed my mind. Smith should have punted and taken his chances with his defense.

I hope it’s pretty obvious what’s wrong with . It’s easy to decide what the right call would have been after the fact. Next time Yasinkas wants to play the lottery, he should ask to see if he can see the numbers that will be drawn first. Read the rest of Galef’s post in which he demonstrates that the Falcon’s actually did make the right call.

I see sports fans making this mistake all the time and I’m sure I do it too. Why didn’t the Canadiens draft Jeff Carter, Ryan Kesler or Ryan Getzlaf with their first pick in 2003 instead of Andrei Kostitsyn (this might seem like an obscure complaint but Habs fans will never forget it)? There is definitely skill involved in assessing hockey talent in young players–some scouts are better than others–but there’s also a lot of unpredictable things that can happen to a young player that makes him a better or worse player than he was on draft day.

I also see people and journalists judging politicians in the same way. We expect our politicians to always make the right decisions and we judge them based on the outcomes of their decisions when we should really be judging them against what the opposition would have done in the same situation (ignoring the fact that the opposition will always say they would have done the right thing).

But there’s another more subtle way people make this mistake. When discussing Canadian healthcare with my more conservative friends I often hear, “why should I have to pay for someone else’s healthcare?” Oh, my dear conservative friend, you don’t get to see the outcome of the lottery before you decide whether you’re going to buy your ticket. In classic Rawlsian style, what if I asked you to choose before you were born, before you knew you were going to be born healthy or with a debilitating expensive-to-treat disease, whether you wanted single payer healthcare or not, would you choose to risk it? Maybe. You might decide you still want to roll the dice but the choice shouldn’t be as obvious anymore.

I would then go on to ask you if it’s fair that someone who has a genetic disease should pay for their disease given that are not to blame for their disease, but that’s for another post.

(via Open Culture)

The first is that a study aiming to measure the Earth’s temperature increase over the past 60 years, and funded in part by people who have been vehement climate change deniers, has shown that the Earth is indeed warming. Of course, this doesn’t placate a lot of the climate change deniers who find ways–although none that seem valid to me–to discredit the study. I mean, there are always tiny things to nitpick about in any study, but the bottom line is would the interpretation of the results change? I also wonder if climate change deniers require the level of evidence they demand on this topic, for other things they believe–the economic policies they believe in for instance.

The second is seven quick facts that demonstrate that people are responsible for altering the climate. Number two in this list was the one that put me over the top on believing that climate change is happening although I find numbers one and four also particularly convincing.

So…can we now put the questions of if climate change is happening and what is causing it behind us and decide what we’re going to do about it?

There are people at the occupy sites who are whining sissies. There are whining sissies everywhere you go. Left-wing, right-wing, youth, elderly, everywhere. That doesn’t mean there’s no issue to be discussed.

There are people at these occupy things who are just saying where’s the can of whoop ass for the people who messed the economy up in the first place?

Or, why can’t an awesome country like the US manage to increase income proportionally for people of all income levels (not that we’re much better in Canada)? The US managed to do that up until around 1980. Did that so-called bottom 99% become lazy all of sudden in 1980?

People who are poor aren’t necessarily lazy. People who are rich didn’t necessarily work harder than everyone else to be so. I think that’s a problem.

Take a look at the graphs on the right. Is the explanation of these graphs that the top 1% work 120% harder than they did in 1979 and that the bottom 20% work 30% less hard? It could even be the case (though how you would measure that I’m not sure) that the rich work harder now than they used to the poor work less, but that cannot possibly explain all of the enormous discrepancy between the wage difference between the rich and the poor.

Or look at this graphic on the left from the NYT (click on it to see the whole infographic). Compensation tracked productivity pretty well until about 1980, but what happened after that? If the economy is more productive than it used to be, where is the compensation? Do you think laziness explains this difference?

Check out Meddling Kids for another good response to this image.

Ok. Back to thesis writing.

It’s easier to keep track of your personal convictions when they’re simple, black and white, propositions: huge corporations are bad, any product with the word natural or organic on it is good and if the Canadiens would have won game 7 last season against the Bruins they would have won the Cup. When we have to start breaking up those beliefs into more complicated, smaller beliefs–smaller beliefs that might actually be closer to reality–it gets hard to remember all the nuances of our positions.

That’s (probably) why there are people who think that genetically modified organisms have a universally negative impact on human well being or that pharmaceutical companies are so profit driven that nothing they do is beneficial. But GMOs do have some positive aspects (see Golden Rice) and, let’s face it, without pharmaceuticals, a good chunk of us would probably be dead right now. The only thing in this world that is singularly bad is seeing a grey world in black and white (see what I did there?)

Matthew Herper drives this point home with respect to pharmaceutical companies:

My other worry here is that an oversimplified view of how financial conflicts affect medicine leads people to miss the point. One problem is that a view of a demonic industry that is simply paying off doctors and cannot be trusted, and thereby leads people to avoid good products like vaccines (see yesterday’s post about Merck and GlaxoSmithkline’s rotavirus vaccines cutting the death rate from diarrhea in Mexico by half) and cheap, generic statins that have been proved to prevent second heart attacks.

Now, the real problem is, and this ties into yesterday’s post about the role of experts, how are busy people supposed to know what pharmaceutical products are the real deal and which are the result of an industry with a seemingly insatiable thirst for profit?

I never know quite what to think about experts. In one sense believing an expert is putting your faith in their knowledge or expertise, but how are you supposed to judge an expert from a non-expert? Based on someone else’s word? Based on how many books they’ve written? Based on who they work for?

It’s not easy. So, should we ever even believe experts? It’s tempting to say no but what would it be like to go through life having to research everything you’re interested in or that might affect you. For health purposes, for instance, you’d have to learn human anatomy, epidemiology, statistics, biochemistry–it very clearly impossible for one person to do their own research on their health, never mind economics, politics, culture, style, etc.

So we’re stuck. We feel vulnerable putting our faith in what experts say, but we can’t live without them because we don’t have the time to do all the research ourselves.

I have  feeling The Trouble with Experts–airing on CBC this Thursday at 9pm–is going to hammer away at the faith we have in experts but I’m curious to know if it will suggest what we should do if we have no experts to do the research for us? Either way, I’m looking forward to sitting down–maybe with a glass of wine–and watching this documentary.

Here’s an excerpt from an interview in the Toronto Star with the The Trouble With Experts’ maker Josh Freed:

Q: Which field is the most rife with bad experts?

A: That’s tough to say. I think maybe health. There are a million of those so-called nutrition and diet experts who claim to have specific foods or cures to help you live forever. Many of them are self-made experts who belong to some association. Ben Goldacre (the British doctor who writes yjr weekly Bad Science column in The Guardian) applied for membership in a nutrition consultants’ association in the name of his dead cat, Henrietta. He now has a fancy certificate saying Henrietta is a member.

I wonder if he considers himself an expert on experts…

(via: Ben Goldacre’s Twitter)