Mr. Earnshaw is the loving father of Catherine and Hindley, although, due to Catherine’s wild nature, Hindley is his preferred child. The family’s stable dynamic is disrupted when Mr. Earnshaw suddenly adopts Heathcliff, a boy seemingly orphaned and living on the streets, whom Mr. Earnshaw takes pity on. Heathcliff quickly replaces Hindley as Mr. Earnshaw’s favorite child, which has negative consequences on Hindley’s self-image and childhood development. Mr. Earnshaw seems deeply unsympathetic to his son’s plight, instead increasingly punishing Hindley for his behavior and rewarding Heathcliff for his, despite the latter’s manipulative and apathetic nature. It is unclear why Mr. Earnshaw is so enamored with his adopted son, to the point that he rejects his biological offspring. Some interpretations of the text theorize that Heathcliff is Mr. Earnshaw’s bastard son, but another possibility is that Heathcliff is simply able to assert the same dominant, unyielding, and almost supernatural hold on Mr. Earnshaw as he does on everyone else in his life. Heathcliff’s forceful presence seems to inspire in others either the utmost hatred or the utmost obsession. For Mr. Earnshaw, it is the latter.
When Hindley leaves to attend college, Heathcliff loses his one source of opposition. Mr. Earnshaw expects the rest of the household to fawn over Heathcliff as he does, instilling in the boy a pridefulness that only makes his fall from grace upon Mr. Earnshaw’s death and Hindley’s return more bitter. Additionally, in his older age, Mr. Earnshaw becomes increasingly mean-spirited, irrational, and violent, despite the fact that his household had previously considered him to be generally kind and fair. Although this change of character is never explained, it again seems possible that the power of Heathcliff’s dark and corrupting nature has continued to worm its way through Wuthering Heights and Mr. Earnshaw’s mind, turning a once-good man into a difficult, disturbed, and sickly one. As his health declines, he’s harsher with the servants and quarrels continuously with Catherine, who is too strong-minded and confident to be cowed by her father’s anger. Catherine provokes her father in the hopes that she might finally receive some of the attention that he most often reserves for Heathcliff.
Despite Mr. Earnshaw and Catherine’s struggle of wills, some love and happiness does remain between the three family members. While Hindley is entirely cast out, Mr. Earnshaw and Catherine are bonded via their love for Heathcliff, and the three share a tender moment on the night of Mr. Earnshaw’s death. Both children weep for their father when they discover he’s passed. However, the damage done to the family dynamic is irreversible, and it only grows more spiteful and malicious after his death. The infighting amongst his children, which he allowed and proliferated via his preferential treatment of Heathcliff and his severe treatment of Hindley, spawns a deep hatred and rivalry between Hindley and Heathcliff that sets into motion generational cycles of misery at Wuthering Heights.