Two roads diverged in a wood, and I- I took the one less travelled by, And that has made all the difference. Cognitive Dissonance is what psychology calls the decision making dilemma faced in this poem. The dissonance or state of disturbance the human mind experiences, when faced with opposing or contradictory cognitions. In the poem what bothers the persona s mind is the possibility of the road not taken proving to be the better one. Frost is playing the role of Everyman as he spoofs man's tendency to make a whimsical choice between two equal imperatives and to praise his choice later as having made all the difference.
People try to make sense of the world they encounter.
They do this by looking for some consistency among their own experiences and memories, and turning to other people for comparison and confirmation. If all checks out, then all well and good. Many social psychologists believe that this will trigger some general trend to restore cognitive consistency to reinterpret the situation so as to minimize whatever inconsistency may be there.