How to Make Better Decisions Based on Science

This post was originally written for the Crew blog.


Unless you’re a cyborg, you couldn’t help but think of the number “4″ when you saw the above expression. In the same way, the partial phrase “bread and” leaves you with the word “butter” on the tip of your tongue. That’s no accident.

Our brains make thousands of decisions every day. Many of them (like whether you want cream and sugar in your coffee) seem to be automatic. Others (like where you want to go for dinner) can be a bit more taxing and require mental effort.

Research has identified two seemingly separate “systems” of the brain responsible for decision-making. In order to make better decisions, we need to understand what each of these systems is responsible for and how we can shift from one to the other.

How we make decisions

Daniel Kahneman was one of the first to popularize the different decision-making elements of the brain in his book Thinking Fast and Slow. In his book, Kahneman classifies two distinct systems in the brain.

System 1 is quick, primitive, and automatic. It’s the reason you can complete the expression “bread and _” without expending any effort at all. System 1 is also part of the reason you can drive on an empty road while jamming out to music and letting your mind wander.

System 2 exists on the opposite side of the spectrum. This system is careful, calculated, and conscious and is involved in situations that require mental effort. Compared to its counterpart that is responsible for finishing “2+2=_”, System 2 becomes active when you’re asked to solve the expression “1769 x 91″. It’s also the mental superhero in charge of parallel parking your car in a tight space.

The interplay between the two systems is crucial. It would be impossible to make every decision in our day using the effortful System 2. We have a limited amount of mental energy that we can allocate to tasks at hand. This mental limit is why you might turn down the radio and stop talking mid-sentence to another passenger while you merge onto a busy highway or drive between two semis. If you attempt to do two mentally-demanding tasks at the same time, you’ll fail at one or both.

That’s precisely where System 1 comes into play. By subconsciously making many of our decisions automatically, we can save up our mental reserves for when it really matters. This works well for tasks like walking (highly automated) and talking on the phone. However, in some cases, System 1 can lead you to errors in judgement.

You might have seen this setup before. Two lines are drawn, one with arrow fins pointing back towards the center and the other with the fins pointing out and away. Which line is longer?

 Line Test

Those of you familiar with the Müller-Lyer illusion will know that the lines are actually the same length. However, your System 1 brain immediately left believing that the top line was just a hair longer than the bottom one.

The illusion mentioned above helps to explain the trouble in just letting our System 1 brain run wild. Since System 1 is automatic and subconscious, it can lead to errors in judgement when left unchecked. The whole business of making better decisions is largely comprised of shifting our thinking from System 1 to more conscious System 2 thinking when necessary.

Improving Your Decision-Making

Switching from System 1 to System 2 is difficult, but research indicates it isn’t impossible. Here are some steps to switching on your conscious thought and making better decisions.

Automate as much as possible.

Our brain gets tired just like a muscle. When our brain is exhausted, we tend to make worse decisions. Researchers from the Harvard Business Review explain, “The busier people are, the more they have on their minds, and the more time constraints they face, the more likely they will be to rely on System 1 thinking.” In short, our brains are just like a muscle. They can become overwhelmed and tired.

This effect is referred to as decision fatigue. As we make more and more decisions, our System 2 portion of the brain becomes exhausted. We begin to opt for easier decisions like stopping for fast food on the way home from work instead of doing what we know we should do like eat a home-cooked meal.

Research has shown this holds up in places you would expect to always judge situations fair and square — the courtroom. Researchers in Israel collected results from over 1,100 court rulings and analyzed the favorability of the ruling and the time during the day that the ruling came down. They found that favorable results (reducing parole length, removing a tracking device, etc) were more likely to happen earlier in the day or after a short break.

 Decision Fatigue Chart

Perhaps the easiest way to combat decision fatigue is to simply make fewer decisions. Tim Ferriss has gone as far as outsourcing his email to Canada and performing the same workout routine for several years to cut down on the number of decisions he makes and save mental energy for the bigger decisions during his day.

You don’t have to outsource your work to another country to reap the benefit. Instead, automate some of the easier decisions in your day:

  • Select from only a handful of lunch options that you rotate each week
  • Use a service like Amazon’s Subscribe and Save to ship common items like paper towels directly to your house.
  • Consider asking wait staff for dinner recommendations so you don’t have to stare at an overwhelming menu

The key is to cut down on the amount of mental energy you expend on trivial decisions so you can save up for the more important choices in your day.

Consider the opposite.

Did you accurately predict who was going to win the 2012 presidential election? Even if you are positive you had it pegged from the very beginning, research says you’re probably wrong.

This mental trap that causes us to feel more confident in our knowledge of events after they’ve happened is called the hindsight bias. When you learned of the results of the election, you immediately connected it with other memories stored in your brain to strengthen the connection. Now that the results are woven into your memory, you’re more confident that you knew it all along.

The hindsight bias feeds into poor decision making in two ways. First, it prevents us from learning. According to Neal Roese of the Kellogg School of Management at Northwestern University:


The hindsight bias can also make us overconfident in our own judgement. If we feel like we were right all along, why would we be wrong next time?

Richard Larrick, professor at Duke University, offers a simple solution — consider the opposite. As Larrick explains “‘Consider the opposite’ works because it directs attention to contrary evidence that would not otherwise be considered.” So, by looking at a situation from a completely different angle as if exactly the opposite had occurred, we can learn things we otherwise would have overlooked and improve our decision-making capabilities for next time the same situation presents itself.

Ask yourself, “What would an outsider do?”

If you have a tough decision to make, the natural thing to do is to run to your best friend and ask for their opinion. We expect others to have a more rational view on the subject. According to the meta-analysis by the Harvard Business Review, this is a great conclusion.

Taking an outsider’s perspective has been shown to reduce decision makers’ overconfidence about their knowledge (Gigerenzer, Hoffrage, & Kleinbölting, 1991), the time it would take them to complete a task (Kahneman & Lovallo, 1993), and their odds of entrepreneurial success (Cooper, Woo, and Dunkelberg, 1988).

In short, taking an outsider’s perspective can help overcome many of the mental mistakes that we make on a daily basis.

The next time you have a tough decision to make try putting yourself in someone else’s shoes. Ask yourself how they would handle the problem.

Consider fewer options.

If you’ve ever been grocery shopping, you know the mental overload that comes from something as simple as picking a brand of peanut butter. The average grocery store has over 40 options!

Compare that to how Trader Joe’s runs its stores. The chain only carries 10 different varieties. Barry Schwartz, author of The Paradox of Choice, explains that this lack of options actually helps consumers to avoid choice overload. Barry explains, “People are worried they’ll regret the choice they made.”

Researchers Sheena Iyengar and Mark Lepper confirmed this choice overload as well. In their experiment, they presented grocery store shoppers with a tasting booth. One set of participants were asked to sample 24 different types of jam. The other group was only presented with six options. The group presented with only six options was far more likely to purchase jam (30% vs. 3%).

The next time you’re trying to make a decision, avoid expanding your option pool. If you’re headed to the movies, consider only two or maybe three movies to see. If you’re going out to eat, consider only a few restaurant suggestions. By limiting the amount of options, you’ll feel more confident in your decision and potentially avoid regret later.


It’s impossible to completely avoid errors in judgement. After all, we make thousands of decisions every day, many of them subconsciously. By engaging our System 2 brain when it really matters, you’ll hopefully avoid errors when the stakes are high.

Photo credit: GreenBook, Museum of Consciousness,, Contact Center Magazine

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