I believe the answer is: Researcher bias; self-fulfilling prophecy
An example of a researcher bias would be a supporter from a democratic party who conducted a research on how well democratic policies resulted in society, and tend to only see the positive sides while overlooking the negative sides.
Examples of self fulfilling prophecy would be someone who believe that he could never achieve anything in life, and choose to not making any efforts because of it. Which lead to them actually not achieving anything in life.