How do we know that regression results are real and not the result of bias?
First, any statistical measure provides only evidence of the truth of something, not proof that it is true. Only a population study can provide proof and in many cases, especially with human studies, it is impossible to nail down a population (since the data changes over time as people grow, change, and die).
One can certainly design a &quot;study&quot; to come to a preconceived result. This is why experimental design is all important and must be disclosed in any research. Then, with all the details of what was done, a reader has the opportunity to replicate the study or to question it. But, assuming the &quot;researcher&quot; isn't just cheating, it is the research design (hypotheses and methodology) that one questions.
While you don't arrive at truth in statistics, you can approach it by replicating studies and also by researching the same hypotheses with different research designs. If they agree, then you have additional evidence.
In some studies, such as those involving racial bias, part of the design might need to be making the data blind in some way to the researchers.
Good papers provide complete design information including reasons for the decisions that were made about data (collection, analysis, possible alternative designs...).