It turns out that something as simple as the clothes you wear can have a profound effect on how people see you, right down to what ethnicity you are. A newly published study chronicled an experiment where social scientists showed subjects pictures of faces that varied between different tones and ethnicities, either paired with a business suit or a janitor's outfit. Faces in the white collar outfit were more likely to be seen as white, and those in the blue collar outfit were more often described as black.
The researchers did more than just track whether the participants thought a face was black or white; they also analysed hand and cursor movements when subjects were trying to decide — and in cases with a "high-status" black face or a "low-status" white one, they had a tendency to move the mouse towards the other side, before settling on an answer.
The effect was unsurprisingly most marked in racially ambiguous faces.
As interesting as this study is, I'd be very curious to know what would happen if more ethnicities were included in the mix, and if you could convincingly add gender too.