Belief bias and belief perseverance are both cognitive biases that affect our critical thinking and decision-making, but they refer to different phenomena.
Belief bias describes people’s tendency to evaluate arguments based on whether the conclusion aligns with their preexisting beliefs.
Belief perseverance is the tendency to maintain one’s initial ideas or beliefs in spite of new and compelling evidence that disproves them.
In other words, belief bias refers to how we evaluate arguments based on our existing beliefs, whereas belief perseverance refers to the persistence of those beliefs in the face of contradictory information.