There's the Minnesota Transracial Adoption Study. The authors found a politically incorrect result and tried to cover it up by inventing a new hypothesis (which they hadn't tested) after they'd collected their data.
I also read a fairly comprehensive secondary research paper trying to support the no-biological-differences theory and when it came to Ashkenazi Jews, they admitted the only plausible explanation was genetic superiority.
This is an area where the science all points in one direction but popular opinion is in the other direction. People don't look at the research. Probably because they don't want to understand, they just want to spread their political ideology. Nobody, as far as I know, has ever shown that no races are inferior.