Pearl in an incarnation of Hester Prynne's and Arthur Dimmesdale's sins of passion; in other words, she is the living scarlet letter. Since allegory conveys its meaning through symbols, Pearl is, thus, symbolic as she represents, not just her parents' passion, but also her mother's integrity and warring spirit against the stringent confines of Puritanism. For instance, she pulls away her hand when Dimmesdale refuses to stand with Hester on the scaffold in Chapter XII, complaining, "Thou wast not bold!--thou wast not true!"
Pearl is also representative of the psychological theme of the true ambiguity of life as opposed to Puritanical thinking. For, she is capricious, free in her thinking like Hester, uncertain like Dimmesdale. For example, in Chapter XIX, the "elf-child" refuses to cross the brook despite the urgings of Hester, demanding that Pearl come to her:
Seen in the brook once more was the shadowy wrath of Pearl's image, crowned and girdled with flowers, but stamping its foot, wildly gesticulating, and, in the midst of all, still pointing its small forefinger at Hester's bosom.
Furthermore, Pearl is allegorical as there is something other-worldly about her, a condition that is an allegorical metaphor for the fact that sin must be admitted because to sin is to be human. For this reason, Pearl does not fully enter the world of humanity until the events of Chapter XXII in which she and her mother stand upon the scaffold with the Reverend Dimmesdale as he finally admits his sin and takes hold of Pearl's hand.
Pearl kissed his lips. A spell was broken. The great scene of grief, in which the wild infant bore a part, had developed all her sympathies; and as her tears fell upon her father's cheek, they were the pledge that she would grow up amid human joy and sorrow, nor for ever do battle with the world, but be a woman in it. Towards her mother, too, Pearl's errand as a messenger of anguish was all fulfilled.
As an allegorical character, both symbol and metaphor, Pearl is one of the most meritable elements of Hawthorne's memorable novel, The Scarlet Letter.