By Kyra-lin Hom

Why do we do the things we do? What makes us think the way we think? And most importantly, if we're such intelligent, clear-minded individuals, why do we make so many bad decisions?! A relatively new and entirely radical theory in (evolutionary) psychology known as “Argumentative Theory” is proposing some of the first plausible answers we've seen yet.

In 2011 Dr. Dan Sperber and doctoral student Hugo Mercier published their paper in the Behavioral and Brain Science journal entitled “Why do humans reason? Arguments for an argumentative theory.” In it they propose that the human power to reason did not evolve to aid us in making the 'right' decision, as is the commonly accepted theory, but rather to convince other people that our decision is or was correct. A subtle but very important distinction – just like this theory that is rapidly gaining support.

Let's start by assuming that the mainstream theory is right, that the weighing and comparing of reasons both pro and con does help us to make good, accurate and appropriate decisions. It should follow then that a single person, by utilizing his or her at least average reasoning skills, will excel at solving logical, statistical and economic puzzles (to name a few). These real life-derived scenarios should be obvious. Our brains should process the provided data smoothly and clearly without any bias. To put it simply, logic and intuition should align. ...Now be honest, how often does that happen for anyone? There is a reason logic is considered one of the hardest fields of philosophy to study.

Here are a few questions compliments of Forbes.com to illustrate what I mean. Think about your answers before reading on.

1) Before Mt. Everest was discovered, what was the highest mountain in the world?
2) Billie was born on December 28th, yet her birthday always falls in the summer. How is this possible?
3) If you were running a race and you passed the person in 2nd place, what place would you be in now?

If you're like me, you probably had a gut reaction to each question. Now because you knew these were trick questions, you probably also knew to immediately doubt your first instinct. This gave you the time needed to apply logic.

Answers: 1) Mt. Everest; 2) Billie lives in the southern hemisphere; 3) 2nd place.

I could further go into economics and the science of consumer choice, but the point is logic and intuition almost never align. Even people who have studied formal logic often fail to objectively evaluate situations on a daily basis. And I'm sure there are even economics professors who still find themselves making the occasional irrational monetary choice.

Argumentative Theory gives us a whole other set of should be's. These make a lot more sense. Essentially if reasoning developed so we can argue effectively and persuasively with others then we should be good at arguing (check), more effective reasoners in diverse groups than by ourselves (check), bloodhounds after data that supports our arguments and less than enthusiastic about data that doesn't (check), and our final decisions should be consistently easy to justify but not always good or better ideas (check). No matter how we might argue to the contrary, lots of research show that these are all true.

This theory also fits snugly with tendencies research psychology already knows people have such as confirmation bias (or cognitive bias) and confabulation. Confirmation bias is the tendency to only seek out information that supports our preexisting biases. This can work miraculously well in a diversely-opinionated group. Think about it. If a group of people with widely varying opinions comes together intent to reach an agreement, each person is going to have a different field of expertise. The final conclusion will likely be a fair and well-advised compromise. This plan of attack, however, falls apart spectacularly when everyone has the same bias (why reasoning alone usually fails) or no intention of reaching any middle ground.

Confabulation is unintentionally lying to yourself or to others. Justifying an impulsive decision post-fact is a perfect example. You didn't actually think about it at the time, but you retell the story as if you had, believing and rationalizing that to be true even though it's scientifically impossible.

Reasoning doesn't mean being fair, objective or right. It means that your decisions are well-justified to the best of your own mind's ability. Big difference. From my understanding, I would say that to be reasonable we need to make sure ours and ones like ours aren't the only opinions we're hearing. Something we could all stand to keep in mind.

If you find this as fascinating as I do, please absolutely find your way to a google search near you. There are a lot more articles on the topic and nearly all of Sperber and Mercier's original work on the theory is available online. Have a wonderful week, everyone!