Project Implicit (https://implicit.harvard.edu/implicit/) is about our conscious and unconscious preferences and biases. For example, most people connote blondes with "dumbness", and tall and handsome with "intelligence"; we don't do it consciously, or we don't want other people to know about our true biases. But even when we try to hide our preferences, we end up revealing them through our attitudes or actions.
The Implicit project tries to measure these unconscious biases. In the test you have to categorize words into different groups, generally two. For example, the gender-science test will ask you to categorize different words into two groups: male/science and female/arts. Then it will ask to categorize words into other two groups: female/science and male/arts. If you are biased about man and science, then you'll take more time to classify science words as female/science than to classify them as male/science. The test will measure your response time and figure out your true preference.
I read about this project in "Blink." Then I took several tests and got very weird results. Like, I don't have any preference for female and science over male and science. But my test suggested that I do. I took another test about preferring self over others, whose result was contradictory as well. I feeling a little confused about myself now.
But it was fun!