For decades, people have tried to “quantify” typefaces according to how we respond to them on a psychological level. But asking science to establish specific legibility and readability values for typography—a subject with way too many variables like x-height and line width and letterspacing—is a little like asking: what is the width of the Atlantic Ocean and why is it a better ocean than the Pacific? 

And as might be expected with such impossible metrics, perhaps we’re no closer to coming to conclusions about typography and psychology today than we were nearly 60 years ago, when A Psychological Study of Typography was published by Sir Cyril Burt. Burt’s 1959 study was undertaken in an attempt to analyze the effects upon a reader of the growing number of typefaces in the world, the increased need to choose amongst them, and the reasons to select one typeface over another.

My secondhand copy of A Psychological Study of Typography had never been withdrawn from the Belfast Public Library; the sheet pasted on the first page for date due stamps was pristine, untouched except for a boxed red imprint, severe and final, noting that it was removed from circulation. I soon felt I understood the reasons (apart from daunting components like “Table 3: Saturation Coefficients for Typefaces”) why the title had never been checked out. This thorny subject is one that’s still yet to be unpacked, and Sir Cyril wasn’t the only scholar to try to quantify typefaces; many others have attempted to pin down the reasons why one font is easier on the eyes than another. 

In her 2003 essay “Cold Eye,” Ellen Lupton analyzed hundreds of pages of typographic studies, some dating back to the 1920s, on legibility (considered an objective quality measured by ease of letter recognition) and readability (considered subjective and measured by ease of comprehension of content). She notes the same difficulties and contradictions as Burt did. While Swiss Modernist design king Josef Müller-Brockmann prescribed narrow columns of type with no more than seven words per line for maximum readability, studies later proved that wider, denser lines are easier to read, even when the typographic crime of horizontal scaling is committed to forcibly narrow the characters to fit more words onto a single line.

So what have we learned from these decades of typographic exploration? In the introduction to A Psychological Study of Typography, Stanley Morison writes, “…it is unnecessary for the reader to inquire whether his book is printed by hand or machine; and whether by letterpress, lithography, or photo-lithography. The normal reader is detached from all these considerations, so long as the mechanism adopted gives him, so far as any mechanism can, the swiftest access to the author’s thought.” 

We can say that readable/legible doesn’t always mean beautiful. And that the world’s wealth of typefaces cannot and will not adhere to a single neat set of rules. And while some obvious facts are verified time and again (it’s generally easier to read long blocks of serif body copy than sans-serif, for example), our understanding of how type works its magic has not evolved very much; typography is an art where science is often inconclusive.