Motivated Reasoning

"The view that machines cannot give rise to surprises is due, I believe, to a fallacy to which philosophers and mathematicians are particularly subject. This is the assumption that as soon as a fact is presented to a mind all consequences of that fact spring into the mind simultaneously with it. It is a very useful assumption under many circumstances, but one too easily forgets that it is false." Alan Turing.


A more basic theory of the phenomena might include the tendency of Bayesian Inference to just get things completely wrong. The prior probability of an untested hypothesis might start at 50% or coin toss chance. When the first new evidence arrives, let’s say ‘paper’ vs. ‘Plastic’ bag at the grocery store. Repeated cognitive effort might lead two different agents, let’s say a Soccer Mom in a big hurry to get food on the table vs. a green hippie tree hugger will use each factoid differently. As a hippie I believe (my first hypothesis) that plastic in any form will harm Gaia. A soccer mom likes plastic because it fits all of the bathroom trash bins and saves on buying MORE plastic in the form of Hefty Trash Sacks. The agents both agree on the PROBABILITY of the evidence – plastic bags are worse than paper bags because of two orthogonal factoids. But the Bayesian method lead to possibly matching or possibly mis-matching desired outcomes. The soccer mom may decide not to line the trash-can and change the INTERPRETATION of the Bayesian result. Paper sacks win the contest when the kids go away to college.

But motivated reasoning outside of a controlled study can never be pinned down. Think of it this way. I know that of the 100 employees I hire only 20 of them will deliver 80% of the goodness I hired them for. The obvious solution is to continuously cull at least the bottom 20% because these individuals actually detract from good outcomes. This is a just so story. The real trick – correctly FINDING the lower 20% is now the big problem to solve. But what are the factoids and what probability do I assign to the evidence that Joe is a water cooler jockey that detracts from the strategic and tactical success of the organization. Again, the HR manager thinks Joe is okay because he turns in his performance objectives on time and always meets the idiotic HR guidelines while guarding the water cooler.
Which facts wins the day? What alternative facts lose the day?
Of course this is just my cognitive bias, I could be wrong.