This last sentence should ring some alarm bells for many readers — it’s a very simple description of confirmation bias. Basically, when we gain a perspective or theory, we tend to interpret everything as confirming that idea. Whatever seems to contradict it is tossed aside or somehow contorted to fit our beliefs.

Popper saw this problem inherent in many theories — both in the physical and social sciences, and in other realms as well. After all, if we find evidence that seems to contradict our beliefs, we should be stopping to see if perhaps we need to abandon or modify our belief.

As a way to cure this ill of self-confirming theories and belief systems, Popper came up with what is now called falsificationism: the idea that a theory or belief system can only be scientific if it clearly lays out what specific evidence would prove it wrong.

Basically, if we’re going to claim that we know something, we have to be willing to admit that we could be wrong about it. More than that, we have to lay out what kind of evidence would prove us wrong. We have to make ourselves falsifiable.

Adopting an attitude of falsifiability does a few key things:

• it helps us to avoid many cognitive biases that can hinder intellectual growth and good decision making
• it makes us clearer thinkers by forcing us to be specific about what we think we know, and what evidence we have
• it boosts our creative thinking by making us naturally more receptive to new ideas and helping us more quickly process them

Our minds tend to run headlong toward safety and comfort. This is true with regards to physical safety and comfort —but it’s also true of intellectual safety and certainty. If we feel like we know something for sure — like we have a firm grasp of it — we want to hold on to that feeling.

And because we want to hold on to that feeling, we tend to manufacture certainty by either stopping the search for new information (fearful that it might endanger our feeling of certainty) or interpreting new information in a way that keeps supporting our feeling of certainty.

The falsifiability mindset is all about thinking through the implications of beliefs, judgments, and decisions. It’s about curbing our craving for certainty. Adopting this mindset is as easy as picking up a simple practice.

For the decision that you’re making, take out a clean sheet of paper, and draw a line down the middle.

On the left side, write at the top “What I Believe to Be True.”

On the right side, write at the top “What Would Prove Me Wrong.”

That left side could be anything. It could be something personal and low-stakes, like “I should buy the new iPhone model” or something more substantial, like “global warming is the result of human industrial waste interacting with the atmosphere”.

The right side is where we will have to do a bit of thinking. That’s where this practice can yield dividends. Having to understand what would prove us wrong forces us to do 3 important things:

• clarify what our actual belief is
• confront the possibility that we could be wrong
• tacitly commit to changing our mind under some specific conditions

Adopting the falsification mindset is simple. Like any exercise in thinking, it helps if you write it out, but that’s not totally necessary.

• For any belief you have, ask what it would take for you to change your mind
• Be specific about what evidence would make you change your mind
• Seek out that evidence, and be willing to change your belief if you find it

Adopting the falsification mindset can be a game changer for an important life decision. But it also works for smaller beliefs and judgments.

Just ask yourself how you could be proven wrong — about any old belief you have. Are you researching a big purchase? If so, what discovery would cause you to cancel the purchase? Are you working toward a professional goal? If so, what new facts or experiences would convince you that this is the wrong goal?

We all have lots of hidden biases that can be examined this way.