The correct term for this idea is "bias." A bias is a prejudice that encourages a person to pass a judgement on something, whether this is positive or negative. However, this judgement is reached without enough information to truly make an informed decision. Therefore, bias is an undesirable thing to have. Moreover, biases can be particularly negative for certain people whose objectivity is particularly important. This is the case with professionals such as politicians, psychologists and journalists.
