And when, not long afterward, the dial gave way to push buttons,
new questions arose: round buttons, or square? How big should they
be? Most crucially, how should they be arrayed? In a circle? A
rectangle? An arc?
For decades after World War II, these questions were studied by a
group of social scientists and engineers in New Jersey led by one
man, a Bell Labs industrial psychologist named John E. Karlin.
Love the bit about the white dots on rotary phones.