In 2012, Errol Morris conducted a provocative test: The writer and director wanted to find out if certain fonts changed the way we perceive what we read, and if the mere appearance of letterforms had the power to sway us to believe a given statement is more or less true. And more importantly, was there some way to prove this empirically?

Morris, a long-time contributor to the New York Times, took to the paper’s website to find out. In something of a sly move, the director presented the experiment under the guise of an innocuous quiz, “Are You an Optimist Or a Pessimist?” Of course, the quiz in question wasn’t about that at all; rather, Morris wanted to see how people responded to a certain passage when displayed in six different typefaces. Readers would encounter either Baskerville, Georgia, Computer Modern, Helvetica, Comic Sans, or Trebuchet—three serif, three sans-serif fonts—and Morris hypothesized that we might be able to learn a thing or two from the way people responded.

Now, Morris is the first to admit that this wasn’t exactly a true scientific experiment, but you know what? That’s okay! Because the findings are still fascinating. As it turns out, people are much more likely to believe something written in Baskerville than any of the other fonts.

Morris mused on his findings in “Hear All Ye People; Harken, O Earth,” a lengthy, two-part essay that originally ran in the Times but has since been printed as the 44th edition of the Pentagram Papers, designed by Pentagram’s Michael Bierut and Jessica Svendsen.

The toothsome paperback provides an intriguing look into an intuitive but little understood truth: typefaces can have an emotional and psychological impact on us. To appreciators of typography (and Kanye West) this probably sounds like a pretty obvious statement. Of course typography has an impact on our judgement; we’re just not always conscious of its effects. And why shouldn’t it? Typography is but one of countless environmental factors that influence our perception of truth or falsity. Morris, for his part, recently said during an interview: “It’s absurd to think that we would be nudged by one typeface over another, into believing something to be true. Something disturbing about it, I’d go so far to say.”

Disturbing or not, it does bring up an interesting question. If we’re able to identify why we trust Baskerville so much—the form, the weight, the context in which it’s presented—is it possible to design a font to achieve certain emotional effects? This is partly what a type designer does, synthesizing fonts that work within certain parameters and constraints. But reproducing an emotional effect is harder to prove, which is why Morris’ experiment was such a novel idea.

So really, what is it about Baskerville that makes it more believable? David Dunning, a professor at Cornell University, says it’s the font’s “starchiness” or the sense of formality and gravitas that lends it the believability that the other tested fonts lack. Bierut likens the reaction to typefaces to the way a voice can impact the way we perceive what’s been spoken. “In a way, typefaces are the graphic equivalent of the human voice, and each voice has a specific timbre and accent,” he says. “In my mind, Baskerville speaks with a calm, confidence-inspiring English accent, sort of like Colin Firth. No wonder it’s so trustworthy.”