One interesting place to start is Harvard's "Project Implicit". They have a massive publication list[1] and you can even test your own implicit reactions[2].
There are plenty of other scientists testing things like whether people judge women as less competent. A quick google search pulled up a PNAS paper where they did an experiment on women in science, for example.[3]
This is just the tip of the iceberg, of course. There is a whole host of related work, testing other sorts of biases and using other methodologies. I'd suggest a search on your favorite academic search engine for "implicit bias".
[1] https://www.projectimplicit.net/papers.html [2] https://implicit.harvard.edu/implicit/ [3] http://www.pnas.org/content/early/2012/09/14/1211286109#aff-...