Legibility is mostly a consequence of training, i.e. habit (see the famous article by Rudy VanderLans in Emigre magazine, in the 90's). For example, the fraktur

Legibility is mostly a consequence of training, i.e. habit (see the famous article by Rudy VanderLans in Emigre magazine, in the 90's). For example, the fraktur typefaces of Germany (the ones you see in nazi movies), they seem unreadable to our eyes. For a more familiar example, programmers seem to prefer aliased or antialased fonts in their editors depending on what they are accustomed to see. When I switched from aquamacs (antialiased) to linux emacs (aliased), I found it unreadable. After some time, the reverse became true.