Dunning–Kruger Effect
The less you know about a field, the more confident you tend to feel about it — especially in your first few weeks in a new role.
Why PMs should care
New PMs — and, importantly, PMs who are senior everywhere else but new to this particular domain — tend to feel most confident right when they should feel most uncertain. They don't yet know what they don't know, so the problem looks smaller than it actually is.
Senior PMs in the same domain sound quieter and more specific about what they're unsure of. This sometimes gets read as lack of conviction, but it's actually the right way to think about a complex, regulated problem.
If you're the new person: pair every confident statement you want to make in your first three months with the question 'what would need to be true for this to be wrong?' If you can't answer that in under 30 seconds, you're probably still on the confidence peak. Quietly downgrade what you're about to commit to.
Example in product work
A PM joins the compliance squad from a B2C growth role. Week three, in the roadmap review: 'the KYC periodic review project is simple, we can ship this in Q2, I don't understand why it's been on the backlog so long.'
Six weeks later they've learned what 'significant influence function' means, what the EMI rulebook says about periodic review cadence for different customer risk bands, why the legacy flow is structured the way it is, and that 'simple' was the wrong word for any of it.
The Q2 commitment is in pieces and the stakeholders are gently reminded every Monday. The confidence in week three wasn't bravery — it was a symptom of not having enough information yet to be scared.
What to do when you see it
- New PMs — and senior PMs moving into a new domain — often peak in confidence right when they should be most cautious.
- When you're the new one in the room, pair every confident statement with 'what would need to be true for this to be wrong?'
- Senior PMs in a domain often sound less sure. That's usually correct calibration, not a lack of conviction.
- If you can't answer 'what could make me wrong here?' in 30 seconds, you're still on the confidence peak.
Sources & further reading
- Unskilled and Unaware of It — Kruger & Dunning, 1999The original paper that demonstrated the effect across four studies.
- The Dunning-Kruger Effect — The Decision LabA careful explainer including the common misinterpretation of the famous curve.