Monday, August 24, 2015

Breakfast and the Science of Consensus

Interesting developments bringing into question the general consensus that "breakfast is the most important meal of the day." Increasing numbers of studies are now showing that this may not be true.
The bottom line of these studies is that no causal link is found between eating breakfast and the various health benefits ascribed to it.  In fact, no strong statistical links can be found between either eating or skipping breakfast and various measures of health.  I recommend reading the linked articles for details.
A couple of interesting side points, as well.

  1.  I heard a story (unconfirmed, but trying to track it down) that this "consensus" had its roots in a clever advertising campaign intended to sell more ham -- a campaign that was NOT directed at potential customers. The genius behind this marketing concept developed slick, glossy pamphlets quoting fictitious studies extolling the virtues of a healthy breakfast of ham and eggs. This was distributed to doctors who then advised their patients about this new research. I don't know if this is true or if I am mis-remembering the story, but it sounds like something an ad company would do.
  2. The linked article nicely illustrates the dangers of using "consensus" as a component of scientific research.  When such a strong consensus is assumed a priori, subconscious biases induce the following problems where researchers 

  • Offered biased interpretation of their own results
  • Improperly used causal language to describe their results
  • Misleadingly cited others' results
  • Improperly used causal language when citing others' work.
On the matter of consensus, I like to think about Dr. Richard Feynman's commentary on the Millikan oil drop experiment, used to determine the charge of electron: 

We have learned a lot from experience about how to handle some of the ways we fool ourselves. One example: Millikan measured the charge on an electron by an experiment with falling oil drops, and got an answer which we now know not to be quite right. It's a little bit off because he had the incorrect value for the viscosity of air.

It's interesting to look at the history of measurements of the charge of an electron, after Millikan. If you plot them as a function of time, you find that one is a little bit bigger than Millikan's, and the next one's a little bit bigger than that, and the next one's a little bit bigger than that, until finally they settle down to a number which is higher.

Why didn't they discover the new number was higher right away? It's a thing that scientists are ashamed of—this history—because it's apparent that people did things like this: When they got a number that was too high above Millikan's, they thought something must be wrong—and they would look for and find a reason why something might be wrong. When they got a number close to Millikan's value they didn't look so hard. And so they eliminated the numbers that were too far off, and did other things like that...

So, if scientists can be wrong for reasons of "consensus" on a single, measurable value of a physical constant, might they be more likely to be swayed by consensus on something as amorphous and unmeasurable as climate change? I think you know my answer to that.

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