Overconfidence Clouds Judgment— Plan with a Pre-Mortem

Have you ever felt completely confident in a decision—only to realize later that you missed a few key details or didn’t quite think through all the consequences?

If so, you’ve experienced what psychologists call the overconfidence bias where your subjective confidence is greater than the objective accuracy. It’s more common than we like to admit.

We tend to convince ourselves that we know “the truth,” even when we haven’t fully vetted our assumptions or explored the downside. That confidence can feel empowering in the moment… until it crashes into reality.

A Personal Lesson in Overconfidence

I’ll admit, I’ve been there myself.

Back in high school, I was laser-focused on attending the U.S. Coast Guard Academy. I didn’t just hope to get in…I believed it was practically a done deal. I knew it was the only military academy that didn’t require a congressional nomination (acceptance is based purely on merit, academics, and extracurriculars).  They had just started to admit women into the Academy and I thought, I’ve got this.

So I didn’t apply to any other schools.

When my dad asked, “What would you do if you don’t get in?” I brushed it off with a confident (read: cocky) reply, “I’d figure it out.”

Fortunately, I did get in and graduated in 1982. Looking back, I cringe.  I realize how reckless that decision really was. Betting your entire future on a single outcome?

That’s not just confident—that’s overconfident.  (FYI, it was NOT a “done deal.”  The Coast Guard Academy is one of THE HARDEST schools to get into – but I didn’t know that!)

So how do you avoid falling into the same trap?

Before charging forward with a decision, especially one that feels too easy or unchallenged, try conducting a “pre-mortem.”  First introduced by Gary Klein in the Harvard Business Review (September 2007), a pre-mortem flips the usual “post-mortem” on its head. Instead of examining what did go wrong after the fact, you imagine what could go wrong before it happens.

Here’s how to do a Pre-Mortem:

1. Imagine it failed.  Assume your decision didn’t work out. Project yourself into the future where everything fell apart.
2. Brainstorm all the ways it went wrong.  Let your imagination run wild. Capture every possible pitfall, even the remote or uncomfortable ones.  List every possible problem that has even a remote chance of occurring.
3. Prioritize the top threats.  Focus on the ten most serious issues, the most likely to happen, or the showstoppers.  Pick ten that would derail your decision or are within your control to prevent.
4. Create a prevention plan.  For each of the top issues, develop a concrete action plan to either prevent the problem or minimize the damage if it arises.
5. Pressure test your thinking.  Ask someone on your team to play devil’s advocate. A fresh set of eyes (especially skeptical ones!) can reveal blind spots and challenge assumptions you might have missed.
6. Implement your plan. Use your pre-mortem to increase your probability of success (or change your mind!)

Overconfidence feels good. It’s seductive. But unchecked, it can lead us into risky territory, blindsiding us with problems we could have seen coming.

The good news? You don’t have to lose your confidence to be wise. Just add a healthy dose of caution—and a solid pre-mortem—to keep your boldness grounded in reality.

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