Behavior is the correct spelling in American English, and behaviour is the correct spelling in British English. Neither one is a misspelling — they are regional variants of the same word, with the same meaning and the same pronunciation. The only difference is a “u” that British English keeps and American English drops, following a spelling pattern found in many other words.
Quick Answer: Is It “Behaviour” or “Behavior”?
Both spellings are correct, depending on which variety of English you’re writing in.
| Behavior | Behaviour | |
|---|---|---|
| Region | American English (US) | British English (UK, and used in Canada, Australia, India) |
| Style guides | AP, Chicago, US academic writing | Oxford, Cambridge, UK academic writing |
| Example | “The dog’s behavior surprised the trainer.” | “The dog’s behaviour surprised the trainer.” |
- Correct (US): She admired his professional behavior during the meeting.
- Correct (UK): She admired his professional behaviour during the meeting.
- Incorrect (in either variety): She admired his professional behavour during the meeting. (missing the “i”)
The real mistake isn’t choosing “behavior” over “behaviour” — it’s switching between the two spellings within the same document.
What Does “Behaviour” or “Behavior” Mean?
Simple Definition
At its core, the word describes the way a person, animal, or system acts — the observable things someone does, especially in response to a situation.
Example: “His behavior changed as soon as his manager walked into the room.”
The word also has a narrower, technical sense in fields like physics or engineering, where it describes how a material, machine, or process reacts under certain conditions.
Example: “Engineers tested the metal’s behavior at extreme temperatures.”
Word Origin and Etymology
The word traces back to the verb “behave,” which entered English in the 1400s from a combination of the prefix “be-” (meaning “thoroughly” or “completely”) and “have,” in the older sense of “to have or hold oneself” in a particular manner. The noun form, “behaviour,” appeared shortly after, in the late 1400s, to describe a person’s manner of conducting themselves. The American spelling “behavior” came later, as part of a broader 19th-century movement in the United States to simplify spellings inherited from British English.
Pronunciation and Syllables
Both spellings are pronounced exactly the same way, since spelling differences here are purely visual, not phonetic.
- Syllables: be-HAY-vyer (3 syllables)
- Stressed syllable: the second syllable, “HAY”
- Simple phonetic guide: bih-HAY-vyer
There is no separate British pronunciation tied to the “u” in “behaviour” — UK and US speakers pronounce the word the same way; any accent differences come from general regional pronunciation, not from the spelling itself.
Behavior vs. Behaviour: American English vs. British English
Key Insight: Why the Spelling Differs
The “u” in “behaviour” comes from French, which heavily influenced English spelling after the Norman Conquest. Many English words borrowed from French kept a “u” in endings like “-our” (colour, honour, favour). When Noah Webster compiled his American dictionaries in the early 1800s, he intentionally dropped the “u” from many of these words to make American spelling more consistent with pronunciation and to distinguish it from British spelling. “Behavior” was one of the words affected by that change.
This is not a random inconsistency — it’s a deliberate, documented spelling reform that also explains why Americans write “color,” “honor,” and “favor” instead of “colour,” “honour,” and “favour.”
Parts of Speech and Word Forms
The word family includes a verb, a noun, an adjective, and an adverb, and each one keeps the regional spelling pattern.
| Form | Part of Speech | US Spelling | UK Spelling | Example |
|---|---|---|---|---|
| Base verb | Verb | behave | behave | “Please behave during the ceremony.” |
| Noun | Noun | behavior | behaviour | “Her behavior was professional.” |
| Adjective | Adjective | behavioral | behavioural | “The clinic offers behavioral therapy.” |
| Adverb | Adverb | behaviorally | behaviourally | “The two groups responded behaviorally in similar ways.” |
Is It “Behaviors” or “Behaviours”? (Plural Form)
Both plural forms exist and follow the same regional rule — “behaviors” in American English and “behaviours” in British English. The plural is used when referring to distinct, countable patterns of conduct rather than behavior as a general concept.
Example: “The report listed several risky behaviors among teenage drivers.”
Some usage commentators note that the plural form has become more common in recent decades, especially in business and psychology writing, where it’s used to describe specific, individual actions (“safe driving behaviors”) rather than a person’s overall conduct (“her behavior was calm”).
Types of Behavior
Behavior is often grouped into categories based on where it comes from and what effect it has.
Positive Behavior
Actions that are constructive, cooperative, or beneficial to others. Example: A student who helps a classmate understand a difficult assignment is showing positive behavior.
Negative Behavior
Actions that are harmful, disruptive, or violate social expectations. Example: Interrupting coworkers repeatedly during meetings is a form of negative behavior.
Neutral Behavior
Actions that don’t carry a strong positive or negative judgment — they’re simply routine. Example: Checking the time during a lecture is a neutral behavior.
Learned Behavior
Actions acquired through experience, observation, or teaching rather than instinct. Example: A child learning to say “please” and “thank you” is displaying learned behavior.
Instinctive Behavior
Actions that occur naturally, without being taught, often tied to survival. Example: A newborn’s reflex to grasp a finger placed in its palm is instinctive behavior.
Common Mistakes When Using “Behaviour” or “Behavior”
Spelling Consistency Mistakes
The most frequent error isn’t misspelling the word itself — it’s mixing both spellings in the same piece of writing, which happens often when a document has multiple authors or editors from different regions.
- Incorrect: The employee handbook describes expected behaviour in Chapter 2 and behavior standards in Chapter 5.
- Correct: The employee handbook describes expected behaviour in Chapter 2 and behaviour standards in Chapter 5.
- Explanation: Pick one spelling based on your target audience or style guide, and use it consistently throughout the entire document.
Subject-Verb Agreement Errors
Because “behavior/behaviour” is a singular, uncountable noun in most contexts, it takes a singular verb.
- Incorrect: The children’s behavior were unacceptable during the assembly.
- Correct: The children’s behavior was unacceptable during the assembly.
- Explanation: Even when describing multiple people, “behavior” in its general sense stays singular unless you’re specifically using the countable plural form (“behaviors”).
Overusing the Word in Repetitive Sentences
Repeating the word too many times in close succession makes writing feel clunky.
- Weak: His behavior at work was different from his behavior at home, and his behavior around strangers was different still.
- Improved: His conduct at work differed from how he acted at home, and he behaved differently still around strangers.
- Explanation: Varying your word choice with synonyms like “conduct,” “manner,” or “actions” keeps writing natural.
Similar Word Pairs: Other American vs. British Spelling Differences
“Behaviour/behavior” belongs to a well-known family of words where British English keeps a “u” that American English drops.
| British English | American English |
|---|---|
| colour | color |
| honour | honor |
| favour | favor |
| neighbour | neighbor |
| labour | labor |
Recognizing this pattern makes it easier to guess the correct spelling for similar words, though a few exceptions exist (for example, “glamour” keeps its “u” in both varieties).
Which Spelling Should You Use?
The right choice depends on your audience, not on which spelling is “more correct.”
- Use behavior if you’re writing for a US-based audience, following AP or Chicago style, or working for an American company or publication.
- Use behaviour if you’re writing for a UK, Australian, Canadian (Canadian English often follows British spelling for this word), or Indian audience, or following Oxford or Cambridge style guidance.
- For international or global audiences, choose one spelling and apply it consistently across all your content, rather than switching based on which word “looks right” in the moment.
Behaviour or Behavior in Everyday Contexts
In Psychology
Psychology uses the word to describe observable actions that can be studied, measured, and sometimes modified. Behavioral (or behavioural) psychology, most closely associated with figures like B.F. Skinner, focuses specifically on how actions are shaped by rewards, consequences, and environmental triggers.
Example: “The therapist used behavioral techniques to help the client manage anxiety.”
In Education
Teachers and schools use the term to describe how students conduct themselves in the classroom, often as part of formal behavior management plans.
Example: “The teacher praised the student’s improved behavior after the intervention.”
In the Workplace
Employers use the word in policies, reviews, and codes of conduct to describe how employees are expected to act.
Example: “Unprofessional behavior in client meetings will be addressed during performance reviews.”
Frequently Asked Questions
Is “behaviour” a misspelling of “behavior”? No. “Behaviour” is not a misspelling — it’s the standard British English spelling, while “behavior” is the standard American English spelling. Both are correct within their respective varieties of English.
Which spelling is used in the UK, and which in the US? The UK uses “behaviour,” and the US uses “behavior.” This follows the same “-our” versus “-or” pattern seen in words like “colour/color” and “honour/honor.”
Do Canada and Australia use “behaviour” or “behavior”? Canada and Australia generally use “behaviour,” following British spelling conventions, though American spelling sometimes appears in Canadian writing due to close proximity to the US.
Is “behavioral” or “behavioural” correct? Both are correct. “Behavioral” is the American spelling, and “behavioural” is the British spelling, matching the same regional pattern as the base noun.
Should I write “behaviors” or “behaviours” in the plural? Use “behaviors” in American English and “behaviours” in British English. The plural form refers to specific, countable patterns of conduct rather than behavior as a general concept.
Why do some British words drop the “u” in American English? This traces back to Noah Webster’s 19th-century efforts to simplify and standardize American spelling, which removed the “u” from many words borrowed from French, including “colour,” “honour,” and “behaviour.”
Which spelling should I use for an international audience or global brand? There’s no single rule — many international brands choose based on their primary market. The most important guideline is consistency: pick one spelling and use it throughout all your content.
Does Microsoft Word autocorrect flag one spelling as wrong? It depends on your language settings. If your document is set to “English (US),” Word will flag “behaviour” as a misspelling, and vice versa if set to “English (UK).” Neither flag means the word is actually wrong — it means it doesn’t match your selected regional dictionary.
Is “behaviour” older than “behavior,” or did one come first? “Behaviour” came first. The noun form developed from the verb “behave” in the late 1400s, centuries before American spelling reforms produced “behavior” in the 1800s.
How is “behaviour/behavior” pronounced — does the spelling change the pronunciation? No. Both spellings are pronounced the same way: be-HAY-vyer, with stress on the second syllable. The spelling difference is visual only.
Can I mix “behaviour” and “behavior” in the same document? You shouldn’t. Mixing spellings within one document looks inconsistent and unprofessional. Choose one spelling based on your audience or style guide and use it throughout.
What’s the difference between “behavior” and “conduct”? “Conduct” is a close synonym, but it often carries a more formal or moral tone, especially in professional or legal contexts, such as a “code of conduct.” “Behavior” is more general and can describe anything from a person’s actions to how a machine responds to input.
Is “misbehavior” or “misbehaviour” the correct spelling for the negative form? Follow the same regional pattern: “misbehavior” in American English and “misbehaviour” in British English. Both describe conduct that violates expected standards.
Practice: Test Your Understanding
- Choose the correct spelling for a document written in American English: behaviour / behavior
- Fill in the blank: The scientist studied the ______ (behave) of the chemical under pressure.
- Correct the sentence: “The students behavior were disruptive during the exam.”
- Choose the correct word form: The clinic specializes in ______ (behavior/behavioral) therapy.
- Identify the noun in this sentence: “Her calm behavior reassured the nervous patient.”
- Choose between similar words: The company’s code of ______ (behavior/conduct) outlines expectations for client interactions.
- Fill in the blank: Please ______ (behave) yourselves while the guests are here.
- Correct the sentence: “He is writing his article using behavior in one paragraph and behaviour in the next.”
- Choose the correct plural form for British English: The counselor tracked several risky ______ (behavior/behaviours) over the semester.
- Identify the adjective in this sentence: “The behavioral study lasted six months.”
Answer Key
- behavior — American English drops the “u” that British English keeps.
- behavior — The noun form is needed here, describing how the chemical reacted.
- Correct version: “The students’ behavior was disruptive during the exam.” — “Behavior” is singular and uncountable in this general sense, so it takes a singular verb, “was.”
- behavioral — The adjective form is needed to modify “therapy.”
- behavior — It’s the subject of the sentence, describing what reassured the patient.
- conduct — “Code of conduct” is the standard, more formal phrase used in professional and legal contexts.
- behave — The base verb form fits the imperative sentence structure.
- Correct version: “He is writing his article using behaviour throughout, for consistency.” — The original mixes both spellings in one document, which should be avoided.
- behaviours — British English plural form, matching the counselor’s British spelling context.
- behavioral — It modifies the noun “study,” describing what kind of study it is.
Final Takeaway
“Behavior” and “behaviour” mean exactly the same thing and are pronounced exactly the same way — the only difference is regional spelling, American versus British. Choose based on your audience, then stay consistent throughout your writing. If you remember one rule, remember this: Americans drop the “u,” the British keep it, and neither version is ever wrong on its own.
