The Debate on Passive Voice in Scientific Writing

Passive or active voice? Scientists have debated this question for decades. During the 20th century, researchers focused on writing objectively, divorcing themselves from their work by describing their actions in the passive voice. But the passive voice carries a price: it weakens the story.

We know that telling a good story is a powerful way to communicate information. Good stories are compelling and memorable. They have concrete characters that perform vigorous actions to achieve a goal: character-action-goal. This order creates a clear, concise, and compelling story.

With passive voice, the order of information is reversed: goal-action-character. In other words, passive voice is when the subject of a sentence receives the action, while active voice is when the subject does the action.

Let’s look at an example:

Active: The scientist counted the cells.
Passive: The cells were counted by the scientist.

The first example is short and precise. You do not question who did what, and you can visualize the action because it immediately follows the subject. The second example is longer and less clear. And to make matters worse, a scientific writer will often omit the subject to make the sentence more concise: The cells were counted.

By omitting the subject (“by the scientist”), the writer leaves the sentence open-ended. Who did the counting? While the answer may seem implied, the reader must fill in that gap. If they need to repeatedly fill in gaps, even subconsciously, you will sap their energy. As a result, they will not enjoy reading your writing, and your story will be less clear and compelling.

Why do scientists use passive voice? Why would they choose the less powerful storytelling tool?

Passive Voice Gives a (False) Sense of Objectivity

Scientists have been trained to be objective in their work, and they believe that their objectivity must come through in their writing. This view was described in a 1996 Nature paper:

“Using the passive voice in scientific writing allows the researcher to stand at a distance from his or her work. By standing at a distance, an unbiased viewpoint is much more likely to be reached. An unbiased viewpoint encourages a world view and an open mind, surely prerequisites for good science.”

This argument suggests that writing in the passive voice keeps you at a distance from your data so that you can be objective about your work. Objectivity is important for good science. However, objectivity comes from how you treat your data, not how you treat your writing. You did the work. You collected and interpreted the data. You wrote the words. You can’t change those facts by changing the writing voice.

More recently, and with good reason, there has been greater support for writing in the active voice, even by prestigious journals such as Nature.

“Nature journals prefer authors to write in the active voice (‘we performed the experiment...’) as experience has shown that readers find concepts and results to be conveyed more clearly if written directly.”

Active voice is more than just clearer. It’s vigorous. It gives you persuasive power in fewer words than passive voice. It infuses your writing with “action”, making your reader feel excited about your work—and you.

Passive Voice Can Be a Powerful Tool

Passive voice is less direct, less bold, and less concise than active voice. But it can be a helpful tool for developing a good story by maintaining perspective and flow, and by controlling who or what the story is about.

Maintain perspective and flow

A rule of thumb in writing is to keep the same subject (character) within each paragraph of your story. If you need to introduce a new topic about your character within that paragraph, passive voice is a great tool to connect sentences.

For example:

Active: The p53 protein influences the cell cycle.

Passive: The cell cycle is influenced by the p53 protein.

Both examples tell a story. The active voice version is clearer and shorter. But if you are telling a story about the cell cycle, the passive voice version would keep the reader’s perspective on the same subject (i.e., the cell cycle). In this way, the passive voice maintains flow in your writing.

Control who or what the story is about

The passive voice can help you compose a sentence when the action that was done is important, but not who did it. For example, in methods sections, we already understand that scientists do the actions. While it has become more acceptable to write this section in first-person active voice, this approach could be repetitive and wordy.

Example:

Active: We treated the cells with the drug, lysed them, and stored them at -20ºC.     

Passive: Cells were treated with the drug, lysed, and stored at -20ºC.

The passive voice also helps you tell the story accurately. For example, in many papers, “we” means the authors. However, what if a technician or intern performed the work, and they are not listed as an author? By using passive voice, you can cleanly and honestly tell a story.

Which Voice is the Better Choice?

Active voice is more direct and compelling, but passive voice is a powerful storytelling tool. However, as with any tool, you need to know their strengths and limitations to make good choices on when to use them.

Be thoughtful when choosing between the active and passive voice. If you have a good reason to use the passive voice, use it with intention. Otherwise, use the active voice. Your writing will be clearer and more concise—and will have a greater impact on your reader.