Five Whys

A root-cause analysis technique: ask “Why?” in response to five consecutive answers.

The method forces people to examine and express underlying reasons for their behavior and attitudes, moving from surface explanations to deeper motivations.

Example from IDEO’s weight-loss research:

• “Why do you exercise?” → “Because it’s healthy.”
• “Why is that important?” → “It raises my heart rate.”
• “Why does that matter?” → “So I burn calories.”
• “Why do you want to burn calories?” → “To lose weight.”
• “Why are you trying to lose weight?” → “I feel social pressure to look fit.”

The first answer is rarely the complete answer. The fifth answer often reveals motivations the person themselves hadn’t fully articulated.

The number five is heuristic, not magic, some chains resolve earlier, others go deeper. The principle is: don’t stop at the first explanation.

Related: 01-atom—say-do-gap