We adopt beliefs because many others hold them—regardless of evidence. Move your cursor to vote. Notice how the majority option pulls your cursor toward it, making it physically easier to follow the crowd. The votes are randomly generated—social proof, not truth.
Move to vote for Option A or B. The larger the crowd, the stronger the pull. Try voting against the majority—feel the resistance.
Watch how the vote counts pull your decision. The majority feels "right" simply because it's the majority.