Shawn, one of Tara’s older brothers, is, at first, rarely present in the narrative, having left the family home to make a living working odd jobs around the area. However, after gaining a reputation for getting into brawls, Shawn returns home, looking for a fresh start. He and Tara begin to build a close brother-sister relationship, and Tara even feels that Shawn takes on a compassionate, protective father-figure role that her own father is unable or unwilling to fill. However, while Shawn is an affectionate older brother at this point in the memoir, his misogynistic and abusive tendencies are already present in his interactions with other characters, such as Sadie. After realizing that Sadie has a crush on him, Shawn subjects her to debasing and humiliating treatment, establishing his total dominance in their relationship. Not long after, Shawn becomes violent with Tara as well.
Although Shawn is characterized as having always been somewhat erratic, his frightening behavior seems to become heightened after he suffers a traumatic brain injury. Brain trauma, an extreme upbringing, and perhaps inherited mental illness from his father all contribute to his violent and aggressive actions. Shawn seeks to dominate others and is motivated by his drive to assert power, especially over women. His abuse of Tara escalates as she goes through puberty and begins to show signs of both encroaching womanhood and increasing self-confidence. Shawn’s derogatory view of women is bolstered and excused by the extreme Mormon ideology they follow. As a child, Shawn sees Tara as an innocent, lovable little sister, but once she shows signs of physical maturity and intellectual independence, Shawn’s perception shifts: in his eyes, Tara has become sinful, corrupted, and a threat against his own position of authority.
Shawn is a bully who wants to crush Tara's spirit, and he takes pleasure in terrorizing her and forcing her to submit to him. Shawn's violent behavior is consistent through the memoir: he abuses both his sisters, and every woman he dates. He continues to display this pattern of behavior even after he gets married and becomes a father. Shawn is rarely, if ever, held accountable for his violent actions. In fact, the Westover family protects him from consequences at the expense of Tara and Shawn’s other female victims. The tragedy of Shawn’s character is that there are genuine moments of love and care between him and Tara, but his inability to overcome his violent and misogynistic tendencies lead to the destruction of their sibling relationship.