Bertrand Russell felt that such thought processes are native to humans:

What a man believes upon grossly insufficient evidence is an index into his desires -- desires of which he himself is often unconscious. If a man is offered a fact which goes against his instincts, he will scrutinize it closely, and unless the evidence is overwhelming, he will refuse to believe it. If, on the other hand, he is offered something which affords a reason for acting in accordance to his instincts, he will accept it even on the slightest evidence. The origin of myths is explained in this way.

Perhaps any reasoning one readily accepts is evidence of bias, and bears deeper examination. Could this be the value of educated criticism, the willingness of others to "give it to me straight", the impetus to fight against the unconscious tendencies of intelligence?