Jill Roberts (Sidney's cousin): She did not want to kill Sidney. She wanted to be Sidney

In Scream 4 (Wes Craven, 2011), the day after her neighbor Olivia is murdered, Jill Roberts is shut in at home on her mother’s orders and complains that she feels like she is under house arrest. Her cousin Sidney Prescott, who has come back to Woodsboro on the last stop of the tour for her book, Out of Darkness, tries to comfort her. Jill asks how she handles it, with people staring at her all the time, and adds that she could never handle that kind of attention. Then she thanks Sidney for saving her life the night before and wonders whether she would have been brave enough to do the same. Sidney answers that she hopes Jill never has to find out. It is a scene of family tenderness, and it is a lie from start to finish. Jill, played by Emma Roberts, is the teenage daughter of Kate Roberts, the sister of Sidney’s murdered mother. (Spoiler warning: this file reveals the ending of the film.) Jill is the Ghostface of Scream 4. With her secret boyfriend, the film buff Charlie Walker, she plans a new massacre on the fifteenth anniversary of the 1996 murders, films it and intends to pin it all on her ex-boyfriend Trevor. The goal is not Sidney. The goal is to take her place.

// The theoryThe grievance of someone who lacks nothing

Relative deprivation was born of a paradox. In The American Soldier (1949), Samuel Stouffer and his team found that soldiers in the branches with the most promotions were the most dissatisfied with promotion, because they compared themselves with the many comrades who were moving up. Robert Merton explained it through reference groups, and the British sociologist W. G. Runciman (1966) gave it shape: a person is relatively deprived of something when they do not have it, see that others have it, want it and believe they could have it. Runciman distinguished egoistic deprivation, felt by someone comparing themselves with their own group, from fraternal deprivation, felt by one group against another. Criminology took it up through the left realism of John Lea and Jock Young (1984), and Young (1999) added a decisive piece: the media include everyone in the same aspirations of consumption and fame while the structure excludes most people, so the comparison is no longer made with the neighbor but with whatever is on the screen.

// The subjectThe perfect victim

The film plants Jill as the new Sidney, and three moments make it plain before the twist. On the way to school, her friend Olivia calls Sidney the Grim Reaper, the Angel of Death, because wherever she goes people die, and Jill answers that she hardly knows her. That night, when Trevor sneaks in through her bedroom window just as Billy Loomis did fifteen years earlier, Sidney walks in on them and tells Jill she reminds her of herself. And at Olivia’s house, after the murder, Jill goes up the stairs, Ghostface steps out from behind a door and slashes her arm: a victim’s wound that, in light of what comes later, serves as her alibi.

The ending is a textbook confession. At Kirby’s house, Jill stabs Sidney and reveals herself. She kills Trevor with two shots and tells her cousin what it was like to grow up hearing “Sidney this, Sidney that”: now, she says, she is the special one. Then it is Charlie’s turn. He expects a knife in the shoulder, like the wounds Billy and Stu gave each other in 1996, and gets one in the heart instead: what the media really loves, she explains, is a sole survivor. She tells Sidney she does not need friends, she needs fans, and that this was never about killing her but about becoming her. Then she wounds herself: she pulls out a clump of her own hair, wounds herself in the shoulder and throws herself onto a glass table. The reporters call her a hero. At the hospital she gives herself away to Dewey by mentioning the “matching wounds” she shares with Gale, a detail she had no reason to know, tries to finish Sidney off in the ICU and dies at her cousin’s hands.

// The crackA grievance without an injustice

Relative deprivation explains Jill’s grievance well, but it is not enough to explain her crimes. The theory was designed for inequality between groups and for collective resentment, and its empirical strength lies there: in the link between inequality and violence, not in the conduct of one particular teenager. The vast majority of people who feel overshadowed by a brother, a cousin or a classmate never kill anyone. Jill adds something the theory does not contain: an almost complete lack of empathy, a talent for manipulation that fools the police, her family and her accomplice, and a meticulous plan. Her mother, she says herself, had to die so that she could stay true to the original, and it was no great loss.

Nor can her case be read as a real injustice demanding redress. Runciman insisted that relative deprivation is not the same as injustice: a person can feel deprived of something they have no right to. Sidney’s fame is not a privilege denied to Jill; it is the price of a trauma Sidney never chose. Explaining Jill is not excusing her. What the theory illuminates is not an excuse but a mechanism: when the reference group is a star and the only visible path to stardom is tragedy, comparison can turn lethal.