Behaviour or Behavior | Meaning, Spelling & Examples

Behaviour and behavior are two different spellings of the noun referring to the way a person, animal, other organism, or machine acts or functions. It’s related to the verb “behave” meaning “conduct oneself” or “act.”

The spelling varies depending on whether you’re using UK or US English:

• In UK English, “behaviour” (with a “u”) is standard.
• In US English, “behavior” (with no “u”) is the correct spelling.

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Behavioural vs. behavioral

The regional spelling distinction carries over to related forms of the words, including the adjective “behavioural/behavioral” and the adverb “behaviourally/behaviorally.”

• In UK English, “behavioural” and “behaviourally” are correct.
• In US English, “behavioral” and “behaviorally” are standard.

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Best behaviour or best behavior

Best behaviour/best behavior is part of the expression “be on your best behaviour/behavior,” meaning “behave very well.” The possessive determiner used in the expression varies depending on the person being referred to. The spelling distinction also applies to this phrase.

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