>>1100421 Psychology of Mixed Case Text.
Mixed Case Letters Are Most Readable
Garvey, Pietucha, and Meeker (1997) studied legibility in road signs. They found that mixed case letters are most readable.
They proposed two reasons:
→ EXPECTATION CONGRUENCE: People expect to see road signs in mixed case. Thus, they process words more easily when the format is congruent with their expectations.
→ GREATER DISTINCTION: Uppercase letters share the same height, thus creating a rectangular block of text. Because mixed case letters are different heights, people perceive more distinction between letters.
https:// www.nickkolenda.com/font-psychology/#fonts-p2-t16
For me personally, mixed case is the most readable. All caps causes the eye to pause repeatedly, and defeats speed-reading.