Gee I wonder how they did this study.
You probably don't need to wonder. With a little effort you can probably find the studies. The articles have links in them. Some go to other articles. At least one goes to a study by Duke University.
Or was that just rhetorical? Do you really not wonder?
Did they just take out their magic racism rulers to measure how racist a person was? Or maybe they went up to every person and asked "Do you believe black people are inherently inferior to white people?"
Yes, I am sure that is how they did it. Sociologists have many different kinds of magic rulers to measure many different things.
In more than one of your posts you have expressed disdain for some ideas from scientists. Why is that? Are you thoroughly versed in these topics? Do you think you are so much smarter than them? Are they stupid? Please explain why you write these snotty, dismissive posts.