To understand the Dursley family dynamic, we need to look back and examine Petunia and Lily’s Evans’ family.
According to The Prince’s Tale (Chapter 23, DH), Petunia and her younger sister Lily had a normal sibling relationship until Lily’s magical future came between them. Petunia was protective toward Lily, fearing exposure of her sister’s frightening special abilities could be dangerous. But suddenly, with a revelation from “that awful boy” Severus Snape, these abilities gave Lily a bright future Petunia couldn’t share. In addition, now Severus was Lily’s best friend and confidante instead of big sister Petunia. Naturally Petunia was hurt and jealous.
Petunia so longed to be magical too that she wrote a desperate letter begging to be allowed to go to Hogwarts. When she received a kindly letter from the headmaster telling her this was impossible, Petunia was crushed and then humiliated when Lily and Severus read the letter.
The Evans parents apparently didn’t handle any of this well. Petunia says to Harry in the island shack, “My mother and father, oh no, it was Lily this and Lily that, they were proud of having a witch in the family!” (SS 53) With Lily getting so much enthusiastic approval, Petunia felt left out and insignificant; this fractured the family, bred resentment, and drove a permanent wedge between sisters.
Channeling her disappointment into hostility, Petunia’s defensive posture was to disdain the magical world and loathe her sister as “a freak” and “weirdo” (SS 53; DH 669). Further, on Platform 9 ¾, while their parents “were looking around with wholehearted enjoyment, drinking in the scene,” Petunia told Lily that “it’s good you’re being separated from normal people. It’s for our safety” (DH 669).
Petunia became obsessed with “normal.” She married young, choosing an older, unimaginative man with equally narrow views who also prized the ordinary. Vernon Dursley buttressed Petunia’s prejudices, making her feel secure and building up her fragile sense of self. In their child Dudley Petunia now had a child who would adore her as her sister once had.
After a childhood of feeling “second best,” Petunia feathered her nest with normalcy and created a new narrative about herself. Never again would she allow anything abnormal or disgusting to have the upper hand; even every speck of dirt in her home was obsessively scrubbed away (HBP 46). Perfection and control made her suburban utopia feel safe and nothing would be allowed to mar it.
Then Harry arrived, a constant reminder of what she thought she’d left behind. She tells him on the island, “I knew you’d be just the same, just as strange, just as—as—abnormal and then, if you please, [Lily] went and got herself blown up and we got landed with you!” (SS 53, emphasis in text).
Petunia was saddled with magical Lily all over again. But this time things would be different.
The Dursleys are the first intact blood family we meet, but intact doesn’t mean healthy. In many ways they mirror the wizarding Malfoys. Both couples are obsessed with material wealth, status, appearance, and normalcy (which for the Malfoys is wizarding blood purity and for the Dursleys human purity). The Dursleys and Malfoys deem themselves superior to those they consider “other,” are bullies and cowards who blame others for their failings, are cruel to children other than their own, and inculcate their children with these values. (The Dursleys and the Blacks also share commonality in rejecting children who challenge the family narrative.)
Instead of learning from it, Petunia carries on the Evans family’s favoritism dynamic. But she turns it around with a vengeance–the “normal” child is favored instead of the magical one.
Without earning it, Dudley is deemed gold, and without deserving it Harry is deemed lead. Dudley has self-esteem thrust upon him through valueless praise and Harry is continually denied it through shaming; neither has opportunity to earn it in a healthy way. But, surprisingly, the children exhibit the same coping mechanisms. Each finds family through whom they can achieve genuine merit outside the home—Dudley through his gang and Harry through the wizarding world. Dudley needs to feel power over others and achieves it by earning his place as top thug, perpetrating evil; Harry needs to feel power over circumstances and achieves it by accruing information that enables him to defeat evil. Dudley’s transformation to a better human being comes from being forced to question his parents’ narrative about himself and Harry after the dementor attack. Harry’s transformation comes in some part from continually proving wrong the Dursley narrative about himself and his parents.
The Dursleys suffocate the children, fawning over Dudley and constantly looming over (while paradoxically ostracizing) Harry. The children, opportunist and survivor respectively, suffer harm in different ways. Instead of meeting these boys’ needs, Vernon and Petunia meet their own needs, and as a result, neither child respects them. This couple is deliberately clueless as to their destriuctive parenting skills and the damage they do to the family, in the name of family.
Unlike most families who tell stories about their relatives and foster a child’s memory of deceased parents, Petunia refuses Harry any memory of Lily and James apart from the lie that they died in a car accident. Harry grows up in complete ignorance about his parents and is never even taken to visit their grave. He’s made to suffer for the “sins” of his parents and those sins are never forgiven.
As OotP opens, Harry sticks to home with the blood family he hasn’t chosen, listening to Vernon and Petunia disparage him and praise the ever-absent Dudley’s social skills, unaware that Dudley is deceiving them as he preys on innocents with his chosen gang family. After the Ministry rescue fiasco, Dumbledore points out that the Dursleys’ abusive treatment, while dreadful, had prevented Harry from growing up as a “pampered prince” like Dudley, spoiled for his destiny and unfit to save the magical world (837; HBP 55).
Dudley’s favored position as son and Harry’s as unwanted intruder is encapsulated in Vernon’s accusation to Harry after the dementor attack (all emphases mine): “What have you done to my son?” (26). Vernon throws Harry out of the house to protect his family (39); he’s eager for Harry, the enemy, to be murdered or sentenced to death. This delineation is further explored in HBP when Dumbledore points out that the Dursleys have mistreated both boys, and especially Dudley. Indifferent to the charge regarding one child (they know and don’t care), Vernon and Petunia are insulted and outraged to be perceived as harmful to the other. Petunia is only “oddly flushed” (with embarassment? Anger?) at Dumbledore’s blunt request to allow Harry a merely legally-defined “home” [HPB 55-56]). A legally-defined home is all they’ve ever offered him.
The tables turn in DH, when Harry is the family adult in charge and the Dursleys are the frightened children. It’s a mark of his tremendous growth that he doesn’t exploit that circumstance.
The Dursleys are painted in broad satirical strokes, but their dysfunction and disturbing behaviors are employed in many households in which the family hearth is a battlefield where the dominant narrative must win.
Their family is a deplorable role model for healthy family life.