There's rather tough review of Simon Swain's Seeing the Face, Seeing the Soul:
Polemon’s “Physiognomy” from classical antiquity to medieval Islam in this week's TLS. I'm very much looking forward to reading this - and I'm keen to see whether I agree with M. F. Burnyeat's comments.
My own contact with theories of physiognomy is fairly limited. Like everyone else who decided to look at science and natural philosophy in Chaucer while an undergraduate, Walter Clyde Curry's Chaucer and the Medieval Sciences (now quite dated but an important book nonetheless I think) was the first book that jumped out at me from the library shelf (actually it was the second, but I decided, wisely, that Lynn Thorndike's multi-volume A History of Magic and Experimental Science would take rather more than an afternoon's work; it's an overwhelming study that still defeats my mental stamina). Curry's book focuses on the physical descriptions of characters in the General Prologue, and the physiognomical implications of each. It is really a very entertaining read - and it's hard not to start to see physiognomical description everywhere once you become interested in it. I dread to think what my out-of-shape body says about me... perhaps a trip to the gym will give me better character.