If... deceit is fundamental to animal communication, then there must be strong selection to spot deception and this ought, in turn, to select for a degree of self-deception, rendering some facts and motives unconscious so as not to betray - by the subtle signs of self-knowledge - the deception being practiced.' Thus, 'the conventional view that natural selection favors nervous systems which produce ever more accurate images of the world must be a very naive view of mental evolution.
Robert Trivers