Nicholas B. Tiller

The blog that unifies scientific skepticism, critical-thinking, health & fitness, and the exercise sciences

  • Nicholas B. Tiller Ph.D.

#44: The 2nd impeachment trial - a lesson in logic and bias

The US Senate convened this past week to argue the conviction of Donald Trump. He was accused of “inciting insurrection” on the US Capitol. After numerous laborious and repetitive speeches on both sides, Trump was acquitted as the Senate failed to reach the two-thirds majority needed to convict.

Although proceedings had the superficial appearance of a balanced trial, the process was instead underpinned by partisan ideological bias, with little if any impartiality. The 2nd impeachment trial, much like the first, was a lesson in the reach of existing prejudice.

As I (somewhat reluctantly) watched the trial unfold, two things really jumped out at me.

First, was the pervasive use of emotive arguments, on both sides. Heavily-edited video presented by the Trump defense depicted dated interviews and speeches in which Democratic politicians invoked aggressive language (almost all of them taken out of context) and interspersed with footage from the Black Lives Matter protests which often turned violent, framed with an ominous soundtrack which transformed the images into a visceral and disturbing collage. It struck me as pure propaganda. The Democrats, in turn, showed footage from Trump’s January 6th speech in which he urged his followers to “fight like hell” while omitting from the video a portion where he subsequently asked them to “peacefully make their voices heard”.

Emotive arguments are used almost exclusively in the health and fitness industry to sell product. The striking “before-and-after” images of a body transformation with a new exercise regimen, or the glossy magazine adverts depicting tanned physiques and glistening abdominals; they’re designed to bypass the logical decision-making centers of the brain (the prefrontal cortex), triggering impulse decisions from the emotion-driven limbic structures like the Amygdala.

Emotive arguments exploit the primal wiring of the human brain, encouraging action from “the gut”. One would expect more composure and precision from such a high-stakes trial.

The second thing that struck me was the ineptitude with which the “prosecution” presented their unconvincing arguments. I don’t mean ‘unconvincing’ in the manner in which they presented the facts, but rather their failure to consider the secondary role that facts would play in the trial given that both sides had already settled into their respective positions. Of course, seven Republicans of 50 voted to convict, but the numbers fell roughly in-line with the popular partisan vote.

As a frame of reference from the exercise sciences, look to the arguments on low carbohydrate diets. Proponents argue that “carbs are the enemy” and almost exclusively responsible for obesity and various metabolic disorders, while opponents argue that a balanced diet is critical for ongoing health and to fuel sports performance.

Both sides exhibit confirmation bias; they favorably interpret evidence in support of their position, while simultaneously ignoring evidence to the contrary. What’s more, both use motivated reasoning to justify their pre-existing stances. For the record, I deliberately sit on the fence in this matter because I haven’t read all the relevant literature. But I know far more about this subject that many people who have already made up their minds. Think about that.

Ideological bias and motivated reasoning are pervasive and show the same traits wherever they manifest; be it in religion, politics, science, or sport.

So why argue with facts in a climate where facts are subordinate to emotion? After all, to quote Jonathan Swift: “you cannot reason someone out of a position that they didn’t reason themselves into”. This is something the Democratic “prosecution” should have considered before the impeachment trial began.

Ironically, it can be ineffective asking people to form opinions that are based on evidence, because we all have ingrained mechanisms of bias which allow us to dismiss evidence that contradict our beliefs. Directly challenging a staunch ideology will provoke a defensive response because nobody likes to be challenged. In these circumstances, you cannot change someone’s mind; instead, you must encourage them to change their own mind. Peter Boghossian at suggests:

"Instead of telling people to form beliefs on the basis of evidence, encourage

them to seek out something, anything, that could potentially undermine their

confidence in a particular belief… this makes thinking ‘critical"

The process of defeasibility encourages an individual to search for evidence that might undermine their faith in something. This is a valid means of determining the extent to which that faith is revisable.

From the outset of this trial, Republicans should have been asked to consider what it would take to shift them, even slightly, from their seemingly immovable position. Would any standard of evidence be acceptable? How would they have responded, on a personal level, if they’d have spoken to a friend or trusted colleague who opposed their position? What if the Trump defense had publicly admitted they had a weak case, or if Trump himself (in some alternative universe) admitted personal wrongdoing? Would any of these occurrences have prompted them to question their staunch ideological stance, or would they have simply doubled-down in any case?

The outcome of the process of a defeasibility test is that you become enlightened as to the extent to which an idea is fixed or finite.

Defeasibility and similar exercises are useful because they cleave a space in someone’s mind for doubt; that crucial word, integral to open and honest enquiry, that detaches us from unwavering faith. Doubt is science’s greatest strength. And without it, nothing new will ever be discovered.