In this video the concept of "belief perseverance" is hilariously and strongly shown. The character Mac tries to persuade his friends about the possible faults in the theory of evolution. He is even quoted as saying "I'm not going to stand here, present some egghead scientific argument based on fact...I won't change my mind, 'cause I don't have to...I won't change my mind on anything, regardless of the facts that are set out before me. I'm dug in, and I will never change." Mac is guaranteed to stick with his initial judgement even in the face of information that Dennis tries to convey on how evolution is real. This is the definition of "belief perseverance" after all. On the reverse-side Dennis also exhibits this concept when Mac makes his argument.