British vs American English in Research Papers

Should you write “behaviour” or “behavior” in your manuscript? “Analyse” or “analyze”? For most researchers the answer is not a matter of taste. It is set by the journal you submit to. Around 5% of words differ between British and American English, and in a research paper those differences affect spelling, punctuation, grammar, and even a few technical terms. Used inconsistently, they signal carelessness to editors and reviewers. Used consistently, they keep the reader focused on your science.

British vs American English – What the Journals Actually Say

Before debating spelling in the abstract, it helps to read the instructions that real journals give their authors. These are paraphrased from major author guidelines and show how varied the requirements are:

The New England Journal of Medicine:
Authors should use standard American English and American spelling — for example, “anemia,” “edema,” and “estrogen” rather than “anaemia,” “oedema,” and “oestrogen,” and “analyze” rather than “analyse.”

JAMA and the JAMA Network journals:
Manuscripts follow American Medical Association (AMA) style, American spelling and usage, and US English.

Nature journals:
Generally use British English spelling and punctuation, but where a term is more common in US English within the relevant specialty, the US variant takes precedence.

The Lancet:
Uses British English spelling — colour, haematology, anaesthetic, centre, paediatric, foetus — while keeping fixed names such as the World Health Organization as spelled.

American Psychological Association (APA):
Determine the preferred spelling using the Merriam-Webster Dictionary, and where a word differs in the APA Dictionary of Psychology, follow the latter.

The BMJ:
Uses US spelling as the most widely recognised internationally, while accepting both “-ise” and “-ize” verb endings.

The pattern is clear: there is no single “correct” English for academic writing. There is only the English your chosen journal expects, applied without exception throughout the manuscript.

Which Variant Does Your Target Journal Want?

If the guidelines are silent: open two or three recently published articles from your target journal and check how they spell words like “organize/organise” and “center/centre.” Match what you find, and keep it consistent from title to references.

Key Takeaways

• Roughly 5% of words differ in spelling between British and American English in academic writing.
• American English typically drops or simplifies letters; British English retains older forms influenced by French, Latin, and Greek.
• The four high-yield patterns are -our/-or, -ise/-ize, -re/-er, and ae/oe simplifying to e.
• Punctuation differs too: quotation-mark placement and the Oxford comma are the most common slip points.
• Consistency matters more than the choice itself — never mix variants within one manuscript.

The Four Spelling Patterns at a Glance

Most British-to-American spelling differences in research writing fall into four predictable groups. Learn the pattern and you can handle most words without a dictionary.

The Influence of Noah Webster

The split traces back to Noah Webster, the American lexicographer who standardised US spelling in the early 1800s. Aiming for spellings that were simpler and more phonetic, Webster’s dictionary gave American English “color” instead of “colour” and “theater” instead of “theatre.” British English, meanwhile, kept the older forms. That single editorial project still shapes which spelling a journal expects today.

Scientific and Medical Terms: The Reference Table

Medical and scientific vocabulary is where the differences bite hardest, because a single inconsistent term stands out to specialist reviewers. The table below covers the most common variants in biomedical writing.

These differences look small, but applied inconsistently they undermine the polish of an otherwise strong paper. When you cite a source, however, never alter the spelling in its title or in a direct quotation — quoted material stays true to the original, even if it uses the other variant.

Punctuation Differences That Trip Up Authors

Spelling gets the attention, but punctuation is where mixed-variant manuscripts most often reveal themselves. Three areas account for most of the trouble.

Quotation Marks and Surrounding Punctuation

In American English, commas and periods sit inside the closing quotation mark:

“The hypothesis was rejected,” she said.

In British English, they usually sit outside the closing mark unless they belong to the quoted material itself. British style also tends to favour single quotation marks for a first-level quote, with double marks reserved for a quote within a quote — the reverse of American practice.

The Oxford (Serial) Comma

The Oxford comma is the comma before the final “and” in a list of three or more items. American English generally uses it for clarity; British English often omits it unless it is needed to avoid ambiguity:

• With (typical US): Researchers analyzed the data, proposed new methods, and published the findings.
• Without (typical UK): Researchers analysed the data, proposed new methods and published the findings.

Whichever you choose, apply it the same way throughout the manuscript.

Abbreviations and Full Stops

American English tends to keep the period in abbreviations such as “Dr.,” “Mr.,” and “U.S.” British English commonly drops it: “Dr,” “Mr,” and “US.” For “et al.” and “etc.,” both variants keep the period. As always, consistency is the rule, and the relevant style guide settles edge cases.

Grammar Conventions That Differ

A handful of grammar habits separate the two varieties, and they surface naturally in research prose.

One useful exception to remember: in British English, verbs ending in “-ise” can also be written “-ize” (both “organise” and “organize” are accepted), whereas American English uses “-ize” exclusively. When in doubt for a British-English manuscript, check the journal’s house dictionary — Oxford University Press, for instance, prefers the “-ize” form.

Style Guides and Academic Standards

Citation style and English variant are linked. Each major style guide carries assumptions about spelling and punctuation, so choosing your style often settles the English question too.

Quick Reference: British vs American at a Glance

For related guidance on getting these details right, see our guides to proper punctuation in academic and scientific writing, maintaining consistency in terminology and abbreviations, and essential editing and proofreading for academic papers.

Common Pitfalls and How to Avoid Them

Three mistakes account for most variant-related problems in submitted manuscripts:

• Silent mixing. Word processors set to one locale autocorrect toward it, so a paper drafted across several sessions or machines can end up half British, half American. Set your document language deliberately and run a final variant check.
• Reusing old text. Pulling paragraphs from a thesis chapter or earlier paper imports whatever variant they were written in. Re-check any recycled text against the target journal.
• Trusting the spell-checker alone. A US or UK spell-check helps, but it will not catch a correctly spelled word in the wrong variant (“center” in a British-English paper passes the checker). A careful proofread — or a professional editor — is what catches these.