English UsageComparison guide
Behavior vs. Behaviour
“Behavior” is the US spelling and “behaviour” is the UK spelling. Use the form consistent with the regional variety or editorial style of the document.
Use “behavior” in American English and “behaviour” in British English.
Key details
Confusion Familyregional-spelling
Noun Variant ScopeBoth spellings name the same concept; the distinction is regional.
Rule Familyregional-orthography
Termsbehavior, behaviour
Choose the right form
| If you mean / need | Use | Why |
|---|---|---|
| American English | behavior | Cambridge identifies “behavior” as the US spelling. |
| British English | behaviour | Cambridge identifies “behaviour” as the UK spelling. |
Further guidance
Core difference
“Behavior” is the US spelling and “behaviour” is the UK spelling. Use the form consistent with the regional variety or editorial style of the document.
Fast Test
Choose by meaning, grammatical function, and documented regional convention rather than treating every visible variant as an error.
Variant Boundary
Both spellings name the same concept; the distinction is regional.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- BEHAVIOR — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · US spelling “behavior”
- BEHAVIOUR — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · UK spelling “behaviour”; entry cross-references US “behavior”