I notice that so long as one affixes the touted word "study" to any given particular, that people don't generally care how it is they've come to the conclusions. They take it on total faith through the assumption that the people conducting such a test have logically and systematically configured it, whether it is so or not.
Then you don't know much about science.
A study like this will get careful scrutiny, to see if there are possible flaws in the methodology used. Sooner or later the study will be repeated, but with a different experimental design. That tests whether the first results could have been a rare statistical event or could have resulted from poor experimental design.
Let's end the political smears