A good typographer doesn't aim for style, he/she aims to get typography out of the way in order to read a text with minimal distraction. Erik Spiekermann put it succinctly when he said "typography is like air, you only notice it when it's bad". I think design will connect to science only when we are able to peek into the brain and see if a person is really concentrated when reading a text, or pleased when he sits down on a really comfortable chair.
This kind of research will bring great dividends in various fields. I can think of anti-depressant medication, architecture, and advertising (perhaps this last one is more controversial).