How is a psychological approach applied in Nathaniel Hawthorne's "Young Goodman Brown"?

In "Young Goodman Brown," we see Sigmund Freud's personality theory being applied to the short story. In Freud's personality theory, the personality or psyche consists of three parts: the id, ego, and superego.

Id: Essentially, the id represents our most primitive and animalistic desires; secret ambitions that may be contrary to social conventions. Our id wants to be satisfied at once. In other words, it seeks immediate gratification and has little patience for social sensibilities or moral considerations. The id works on the pleasure principle.

Ego: The ego works on the reality principle. It works on helping the id realize its desires without incurring societal disapproval. The ego takes into consideration social norms and expectations.

Superego: Basically, the superego is the voice of our conscience. It incorporates moral values into the decision-making process. The superego induces guilt if the ego gives way to the demands of the id.

In "Young Goodman Brown," we can see these three parts of the psyche in action. The id is represented by old Goodman Brown (the grandfather of young Goodman Brown). Old Goodman Brown seems to revel in Goody Cloyse's description of being "anointed" by the "juice of smallage and cinque-foil and wolf's-bane ... mingled with fine wheat and the fat of a new-born babe."

Later, during the "witch-meeting," old Goodman Brown proclaims that "Evil is the nature of mankind. Evil must be your only happiness." However, young Goodman Brown shrinks at this proclamation. He (like many in his congregation) acts according to the dictates of the superego. Goody Cloyse, for example, is described as an "excellent old Christian" who teaches young children their catechism.

In the beginning, the superego reminds young Goodman Brown about his moral obligation to make the right choice and turn away from the wrong path. It highlights the feelings of joy and satisfaction that can come from doing the right thing.

And what calm sleep would be his, that very night, which was to have been spent so wickedly, but purely and sweetly now, in the arms of Faith!

However, as the story progresses, the id overrides the claims of the superego. For its part, the ego isn't able to reconcile the primitive desires of the id with the moral duties presented by the superego. Thus, young Goodman Brown, in his inability to reconcile the conflicting demands of the id and superego, becomes mired in neurosis.

Often, awaking suddenly at midnight, he shrank from the bosom of Faith, and at morning or eventide, when the family knelt down at prayer, he scowled, and muttered to himself, and gazed sternly at his wife, and turned away. And when he had lived long, and was borne to his grave, a hoary corpse, followed by Faith, an aged woman, and children and grand-children, a goodly procession, besides neighbors, not a few, they carved no hopeful verse upon his tombstone; for his dying hour was gloom.

How does Nathaniel Hawthorne use Young Goodman Brown to explore human psychology?

Psychologically, Young Goodman Brown travels one night from belief in what the minister preaches on Sabbath--

sacred truths of [his]religion, and of saint-like lives and triumphant death and of future bliss

--to the knowledge of his Calvinist tenets of "misery unutterable" and a comprehension of the full meaning of his Puritan faith.  In the beginning of Hawthorne's story, Brown displays unwittingly his Calvinistic depravity as he agrees to walk with the devil. Yet, he deludes himself by believing that he is among the elect who are chosen for heaven:

"...after this one night I'll cling to her [Faith's] skirts and follow her to heaven"

As he traverses the path with the devil, however, Brown learns of the hypocrisy in his family; for, when he mentions his ancestors, declaring them good Christians, the devil chuckles and responds that he has been well-acquainted with Young Goodman's relatives and would "fain be friends with you for their sake." Farther into their journey, Goodman is shaken by the sight of Deacon Gookin and Goody Cloyse, who has taught him his catechism and been his "moral and spiritual adviser."  Thus, Hawthorne, as narrator, suggests that Young Goodman Brown has been taught about evil and depravity.  Goodman and the devil continue to walk on the path, but Goodman tries to hide from himself his "guilty purpose" for coming to the black mass. Continuing on his path, Brown cries out,

"With heaven above and Faith below, I will yet stand firm against the devil!"

But Faith is already at the black sabbath, lost in the depravity, and not awaiting his return. It is, then, in a torturous epiphany at which Young Goodman Brown admits to his Calvinistic sentencing.  In his essay "Hawthorne's 'Young Goodman Brown': An Attack on Puritanic Calvinism," critic Thomas E. Connolly contends, 

Goodman Brown did not lose his faith; he learned its full and terrible significance.

Goodman Brown moves from trust in his faith and a belief in his being part of the elect to the knowledge that there is little but misery in store for him in his Calvinsitic depravity, a state which leaves him nothing with which to merit salvation.