The prevailing assumption is that that a person accumulates data, analyzes it, and, based on logical processing of the data, comes to a conclusion. Talking to people who plan to vote for Donald Trump, and based on years of consulting to top management and politicians, I have a different opinion.
People do not come to a decision with a tabula rasa, as a clean slate.
They do not look at data rationally and decide free of biases. Rather, the opposite seems to be true. First they decide, then they look for data that will support the decision they already took. Any data that do not support the decision they already made is either ignored or explained in ways that make it irrelevant.
That is why it is said that the first impression is the critical one: That is where you really make your decision. The rest is commentary.
The a priori decisions people make are based on their past experiences, which often have little to do with the decision they are making now. Nevertheless, they serve as the driving force behind making the new decision.
I find that the a priori decision is influenced heavily by the physical make-up of the person deciding. There is evidence, for instance, that being conservative or liberal is influenced a lot by an individual's hormones.
Even in the field of science this upside-down rationale is common. We first formulate a hypothesis, then look for data to prove the hypothesis is true.
In medical research it is sometimes possible to be free of bias and run controlled experiments that might yield "the truth" because, in pure biology and chemistry, bias is limited. That is not true in politics, in social sciences, or in what matters to our day-to-day behavior.
In social sciences you can rarely design double-blind tests. When double-blind experiments are created, it is to test a very limited, simple, and perhaps almost irrelevant hypothesis, one that is often highly divorced from real life. I find a lot of the "scientific" research in behavioral science laughable.
It is dangerously amusing to listen to those who intend to vote for Donald Trump. They ignore facts that show the guy lies a lot, switches positions, and is superficial in his conclusions regarding very complicated situations. Why will these intelligent, educated, successful people vote for him? Don't they see what I see, that the persona he projects is not the persona that his past behavior or achievements support?
I believe my insight holds: They first chose him because they were angry, or desperate for change, or fearful of something, like the direction the country is taking. They support him because they believe he is the answer to their fears and confirms their biases. Something that he said resonates with them. From there on, they ignore or explain away whatever else Trump says. They ignore the data that should lead them to change their mind.
We are not free to decide based on evidence. We are selective in the evidence we choose to use. We are, first of all, biased and use logic to support our bias. Scary.
Ichak Kalderon Adizes