1
general::
How one acts is more important than how one looks. For example, He may be homely, but he's the kindest man I've ever met? handsome is as handsome does. This expression already appeared in John Ray's 1670 collection of proverbs.
American Heritage Idioms
2
general::
Phrase(s): Handsome is as handsome does.
Prov. It is more important to treat people well than to be good-looking.; Just because you are good-looking does not mean you are a good person. • Jill: I’d like to get to know George better. Jane: Why? Jill: He’s so handsome. Jane: Handsome is as handsome does. He’s a very unpleasant person.
McGrawhill's American Idioms And Phrasal Verbs