I just finished two class sessions on ‘Is smoking bad for you?’. We all know the answer, but its powerful stuff to teach to. By 1950, literally millions of people were dying horrible deaths because the science was not being done properly. Indeed, the way to do the science properly had not yet been invented. A decade and a half later, all the lines of evidence we have now were in hand (to be fair, maybe the exact biological mechanisms involved were only slightly more mysterious then than they are now). And the smoking rate in my class is 18%.
The broader implications are also profound. It took 50-100 years to figure out a single factor with ENORMOUS health risks, and it was contentious for decades. What hope then for public discussion on something when the effects are smaller (high fructose corn syrup?) or multi-factorial (colony collapse disorder in bees?), or where the same level of experimental data simply is not possible (climate change?). This is a key point to deliver to the class: things go seriously awry without the scientific method; but equally, the scientific method is often incapable of delivering complete certainty – and on the way, it can be powered by and generate controversy.
Next year, I might teach the whole thing the other way around. Could I step in front of the class and by ‘revealing’ new (ie made-up) data analogous to smoking, convince the class to stop eating ice cream?