Science requires you not to have any preconceived notions before setting out to find answers. Hindrances are :- Your own mind, upbringing, cultural mores, education. Peer pressure. Dogmatism saying something is true with no grounding. Mysticism saying something is magical because you don't understand it. Selective observation, over generalizing, authority ie some authorities not want you printing the whole truth as it adversely affects their aim. Ego involvement, illogical reasoning, human error, made up information.