The U.S. Centers for Disease Control and Prevention is typically tasked with conducting critical science, and its myriad jobs include trying to prevent Zika-related birth defects and the spread of sexually transmitted diseases among transgender women. But when the CDC makes its case for 2018 budget funds, it should not use seven specific words: evidence-based, science-based, vulnerable, fetus, transgender, diversity or entitlement, according to the Trump administration.

The news, broken by The Washington Post, sent tremors through the public health and policy communities. “Are you kidding me?!?!” tweeted Democratic Sen. Jeff Merkley of Oregon. “This. Is. Unacceptable,” wrote the American Public Health Association. The Department of Health and Human Services, which oversees the CDC, did not immediately respond to Scientific American’s request for comment.

How much does it really matter if a government agency avoids certain language in documents sent to Congress, the Office of Management and Budget and other agencies?

Perhaps a great deal. Scientific American spoke with Lera Boroditsky, a cognitive scientist at the University of California, San Diego, about the significance of this recent news, why words matter and how language changes our perceptions of the world.

[An edited transcript of the interview follows.]

What happens when we use certain words and not others in our daily life or in our work?

Words have power. If I tell you this hamburger is 80 percent lean as opposed to 20 percent fat, then in some sense I am communicating the same thing. But what people get from those two communications is very different: People perceive the 80 percent lean hamburger as much healthier than the 20 percent fat option. By choosing how you frame and talk about something, you are cuing others to think about it in a specific way. We can drastically change someone’s perspective by how we choose to talk about and frame something.

You’ve written for Scientific American before about the Sapir–Whorf hypothesis—the idea that when a community has seven words for snow instead of one, its perception of that white, flaky material is different. We still have words like “diversity” and “transgender” in our lexicon, though perhaps we won’t have them in these official government documents. So why does this change matter?

This won’t erase those ideas from people’s minds and the conversations we have on the street, but if it dampens those conversations in the spheres that end up controlling a lot of our lives—where our cash will go and what policies and laws should be in in our culture—then that’s really important, because those conversations have tremendous power.

What happens to our perceptions of the world when we don’t use certain words?

There are two outcomes that happen when we don’t name or talk about something. Things that are named are the ones most likely to be thought about and to be visible in our consciousness. Though in principle we can think about lots of things, our actual attentional span is very limited. As a result, the kinds of things we tend to think about are the ones that are named.

But the other issue is administrative. The basic idea is that what isn’t named can’t be counted. And what can’t be counted can’t be acted upon. If a word like “transgender” is never mentioned—or categories like race or gender are never recorded in official documents—then you can never have data about how services, violence, social ills or outcomes are distributed across those groups. So if you ever want to see if we have a problem in policing related to race, pay related to gender or a problem with violence against transgender individuals, in all of those cases it becomes impossible to make a scientific argument—because if those categories are never recorded in official documents, you can never do the data collection to show what’s true. If you make those categories administratively invisible, you don’t have to deliver those services.

What happens in the brain when we try to avoid certain words?

Words are really categories of things. So, take color. There’s a giant continuum of blues, but the word “blue” creates a category that is different than yellow or green. And when you learn that, you brain starts to treat everything in that group a certain way. But if you make a distinction between the blues, as some languages do, the brains of those speakers will give a surprised reaction if you switch from light blue to dark blue in a way that English speakers won’t—because the English speakers treat both blues as categorically the same.

So what’s the significance of having that “surprised” reaction or not, beyond academic intrigue?

There are some things we are trained to notice and think of as different, and others that are similar. The reason to erase the word “fetus,” I assume, is to make human life be seen as continuous from the point of conception—so there’s not a separate category that exists before a child or a baby. That is a way of taking out a categorical distinction in the medical world between conception and child and treat it as one continuous category. That maps on perfectly to the light blue and dark blue example, because we take this continuum and treat all the things in it as the same. Here, all things across the whole life span would be viewed the same—including conception.