Hanlon's Razor

How it works

Humans have a well-documented tendency called the Fundamental Attribution Error: when other people do something that affects us negatively, we tend to assume it reflects their character (“they’re selfish”) rather than their circumstances (“they were overwhelmed and forgot”).

Hanlon’s Razor is the corrective. Before assuming someone acted with bad intent, consider simpler explanations: they didn’t know, they were distracted, they made an honest mistake, they had different information than you, they didn’t think through the consequences, or they were dealing with their own problems.

This doesn’t mean malice never exists. It means malice is the last hypothesis, not the first.

Case study: How the Mars Climate Orbiter was lost to a unit conversion error

In September 1999, NASA lost the $125 million Mars Climate Orbiter. The spacecraft approached Mars at too low an altitude and burned up in the atmosphere. Initial speculation focused on sabotage, software corruption, or fundamental design flaws.

The actual cause was far more mundane: one engineering team at Lockheed Martin was using imperial units (pound-seconds) while NASA’s Jet Propulsion Laboratory was using metric units (newton-seconds). Nobody caught the discrepancy during months of mission operations. There was no malice, no sabotage, no grand failure of engineering. Just a unit conversion error that nobody noticed.

The instinct is to search for dramatic explanations when dramatic things happen. Hanlon’s Razor reminds you to check the mundane explanations first. The most expensive mistakes often have the most embarrassingly simple causes.

Real-world examples

Workplace. Your colleague didn’t CC you on an important email. Attribution to malice: they’re trying to cut you out. Hanlon’s Razor: they were writing quickly and forgot, or they didn’t realise you needed to be included.

Relationships. A friend cancels plans last minute. Attribution to malice: they don’t value your time. Hanlon’s Razor: something came up, they’re bad at planning, or they’re going through something they haven’t shared.

Customer service. A company charges you twice. Attribution to malice: they’re scamming you. Hanlon’s Razor: it’s a billing system glitch, and the support agent would fix it if you called.

When to use it

Apply Hanlon’s Razor whenever you feel a flash of anger or betrayal at someone’s actions. It’s especially powerful in email and text communication, where tone is absent and misinterpretation is rampant. It’s valuable in management, parenting, teaching, and any context where your interpretation of intent affects your response.

Common mistakes

The main mistake is applying it absolutely. Some actions really do reflect bad intent, and naively assuming otherwise can leave you vulnerable. The razor is a starting hypothesis, not a conclusion. The second mistake is using it to excuse repeated patterns. If someone “accidentally” undermines you every week, that pattern is itself evidence worth considering.

Try it now

Think of the last time someone annoyed, frustrated, or upset you. Write down the action that bothered you. Now write three non-malicious explanations for why they might have done it. Does any of them feel more plausible than your initial interpretation?

Related models

These models complement Hanlon's Razor — they address similar situations from different angles.