First Author

What the first-author position means

“First author” refers to the name that appears first in a scholarly work’s byline. In the fields that use a contribution-ranked author list — biomedicine, the life sciences, and much of the natural sciences most consistently — readers, hiring committees, and funders conventionally interpret that position as a signal that this person carried out the largest share of the practical work behind the paper: the experiments, the primary data collection or analysis, and usually the first draft of the manuscript itself. It is one of a small number of byline positions that carry an informal but widely understood meaning on top of the formal authorship test — alongside corresponding author (who handles submission and post-publication correspondence) and, in many of the same fields, the “last author” or senior-author slot (conventionally the supervising principal investigator).

It is important to be precise about what the position is and is not. Occupying the first-author slot is not itself an authorship criterion — it is a ranking applied after everyone on the list has already qualified as an author. Most journals and funders anchor the underlying qualification question to the ICMJE’s four-part test: substantial contribution to the work’s conception, design, or data; drafting the work or critically revising it for important intellectual content; final approval of the version to be published; and agreement to be accountable for the work. All four conditions have to be met together by every listed author, first or otherwise — see CASRAI’s Authorship entry and the fuller ICMJE Authorship Criteria guide for that underlying test. First-author status answers a narrower, secondary question: given that everyone listed has already qualified, whose contribution was largest.

Why the position is read as a primary-contribution signal

The convention exists because a traditional citation only records a name and a position, not a description of what that person actually did. In a field without a structured contribution record, byline order became the available shorthand — and first position became shorthand for “principal doer of the work.” That shorthand is load-bearing in practice: it is commonly weighted in hiring, promotion, and tenure review, and is one of the more visible lines on an academic CV.

That same load-bearing weight is exactly what makes the position contested when it doesn’t match reality. Because first-author position is the only visible signal in a traditional byline, contributors reasonably — but often incorrectly — treat it as the sole measure of their input, which raises the stakes of every ordering decision on a paper well beyond what a bare position was ever built to carry. Where a project genuinely had two or more people doing comparable amounts of first-author-level work, some fields have adopted co-first authorship (also called joint or shared first authorship) as an explicit note attached to the byline stating that the listed order does not reflect unequal contribution. Where the position is disputed rather than shared, that is a distinct problem with its own resolution process, covered in CASRAI’s Resolving Authorship Order Disputes guide — this entry defines what the position means; that guide covers what to do when people disagree about who should hold it.

A more precise alternative: CRediT

Because byline position only ever carried an informal, field-specific meaning, a growing number of journals now ask authors to also submit a structured statement of who did what, using the Contributor Roles Taxonomy (CRediT), formalized as ANSI/NISO Z39.104-2022 and jointly stewarded by CASRAI and NISO. CRediT does not replace byline order and does not decide who is first — it runs alongside the byline and names each author’s specific role (Conceptualization, Data curation, Formal analysis, Writing – original draft, and eleven others) independent of where their name sits in the list. In practice, a first author’s CRediT roles very often include Investigation, Formal analysis, and Writing – original draft, since those are the activities the position conventionally signals — but CRediT states this explicitly, per role, rather than leaving it to be inferred from position.

Where the convention does not apply

First-author position is a real signal only in the fields that use contribution-ranked bylines. It is not universal. In mathematics, economics, and parts of theoretical physics, authors are conventionally listed alphabetically by surname regardless of who contributed what — a convention the American Economic Association explicitly documents and endorses for economics. Reading “first author” as a contribution signal in an alphabetically-ordered field is a mistake, not just an edge case: in those fields, the position genuinely carries no ranking information, and evaluators (hiring and tenure committees in particular) who assume otherwise are misreading the field’s own convention. Large multi-institutional collaborations in fields like particle physics add a third model entirely, where authorship and often ordering are granted collaboration-wide under the group’s own membership rules rather than assessed, or ranked, contribution by contribution.

Related terms

• Co-First Authorship — the convention for marking genuinely equal top-ranked contribution.
• Corresponding Author — a separate byline role (submission and post-publication contact), not necessarily held by the first author.
• Authorship — the underlying qualification test every listed author, first or otherwise, must independently satisfy.
• Authorship Dispute — what happens when position or credit is contested.

Frequently asked questions

Does being first author mean you did the most work?

In fields with contribution-ranked bylines (most consistently biomedicine and the life sciences), yes — that is what the convention is understood to signal. In alphabetically-ordered fields such as economics and mathematics, no — position carries no contribution ranking there at all, so the same question has a field-dependent answer.

Is the first author always the corresponding author?

No. These are separate roles that are sometimes, but not always, held by the same person. The corresponding author is whoever is designated to handle submission logistics and post-publication correspondence — often the senior or supervising author, sometimes the first author, and occasionally a third person entirely. See Corresponding Author.

What if two people should both be first author?

That is what co-first authorship is designed for — an explicit note attached to the byline stating the order does not reflect unequal contribution, used when two or more contributors genuinely did comparable amounts of first-author-level work.

What if authors disagree about who should be listed first?

That is an authorship-order dispute, a distinct problem from the plain definition covered here. See CASRAI’s Resolving Authorship Order Disputes guide for why these disputes happen and how CRediT and journal policy help resolve them.