5. A striking similitude between the brother and the sister now first arrested my attention; and Usher, divining, perhaps, my thoughts, murmured out some few words from which I learned that the deceased and himself had been twins, and that sympathies of a scarcely intelligible nature had always existed between them.

In “The Fall of the House of Usher,” the narrator makes this observation about Roderick and Madeline Usher when he helps to bury Madeline after her apparent death. This quotation makes explicit the motif of the doppelganger, or character double, that characterizes the relationship between Roderick and Madeline. Poe philosophically experiments with a split between mind and body by associating Roderick exclusively with the former and Madeline exclusively with the latter. The doppelganger motif undermines the separation between mind and body. Poe represents this intimate connectivity between mind and body by making Roderick and Madeline biological twins. When sickness afflicts one sibling, for example, it contagiously spreads to the other. The mode of contagion implies an early version of ESP, or extrasensory perception. Poe insinuates that these mysterious sympathies, which move beyond biological definition, also possess the capacity to transmit physical illness. It is also possible to view these sympathies as Poe’s avant-garde imagining of genetic transmission between siblings.

Poe suggests that the twin relationship involves not only physical similitude but also psychological or supernatural communication. The power of the intimate relationship between the twins pervades the incestuous framework of the Usher line, since the mansion contains all surviving branches of the family. The revelation of this intimacy also reaffirms the narrator’s status as an outsider. The narrator realizes that Roderick and Madeline are twins only after she is nearly dead, and this ignorance embodies the fact that the walls of the Usher mansion have protected the family from outsiders up to the point of the narrator’s arrival. When the narrator, as an outsider, discovers the similitude between Roderick and Madeline, he begins to invade a privileged space of family knowledge that ultimately falls to ruins in the presence of a trespasser.