The environment and heredity are both prevalent themes in this novel, with the environment involving the two households in the novel and with heredity involving all the major and most of the minor characters. Since these two themes include the characters and the different settings, they are involved with the structure of the novel and are therefore very important to the story. The theme of heredity is very complex because of how it changes throughout the novel. As new characters are introduced, new hatred and love arise between them, while the theme of environment stays the same and strengthens while the story moves on.
With each household contrasting the other and the tenants suiting the home they reside in, we see a commonality between the two. Wuthering Heights is described as a bad environment because of the characters that reside there, and the way the house is maintained. Most of these characters are from the Earnshaw and Heathcliffe families. Most of the characters from these families that reside in Wuthering Heights have an imperfection of some sort, whether physical, emotional or mental.
Hindley Earnshaw and Heathcliffe are the two characters that began this degradation and were responsible for ending it. After years of living with each other Hindley had a drinking problem and wanted to kill Heathcliffe, who himself despised Hindley. This anger was also directed at the Lintons in Thrushcross Grange due to Heathcliffe's hatred for them, specifically Edgar. Hareton, Hindley's son, was originally an illiterate and violent male, while Linton Heathcliffe had a natural weakness to getting sick.
Characters that move from other households into Wuthering Heights acquire negative qualities as well. Cathy Linton was originally very polite and cheerful, but once she was forced to live in Wuthering Heights she became hurtful and critical "'I don't want your help,' she snapped; 'I can get them for myself.' ... .' You scandalous old hypocrite!' she replied... .' I'll show you how far I've progressed in the Black Art:' ." Seeing as this house is home to many mean spirited characters and turns good, decent people into generally bad individuals it can be said that symbolically this is some sort of hell. In contrast with Wuthering Heights, Thrushcross Grange is a pleasant place to be, and the characters that live there prove this.
With Wuthering Heights making people mean spirited Thrushcross Grange does the opposite and makes people proper. This is true with Catherine Earnshaw. She originally was very rebellious against her father, but once she resided in Thrushcross Grange for several weeks she became very proper "Catherine had kept up her acquaintance with the Lintons... and as she had no temptation to show her rough side in their company" (Wuthering Heights, pg.
69). The people that lived there originally were proper too, for example Edgar Linton, who was a major influence on Catherine's transformation. Before being forcibly moved to Wuthering Heights, Cathy Linton was a very cheerful and proper lady as well. For a household that houses such proper people, it is no surprise that the house itself has a proper look to it; a look of high class "A splendid place carpeted with crimson, and crimson-covered chairs and tables, and a pure white ceiling bordered by gold, a shower of glass-drops hanging with silver chains from the centre, and shimmering with little soft tapers." (Wuthering Heights, pg. 51). With the luxurious house and the polite and proper people that reside in it, Thrushcross Grange could be interpreted as a symbol of Heaven.
What is interesting about this novel is how there is a union with the household and the residents. Wuthering Heights is described negatively as being a desolate and dead home with horrible weather "On that bleak hilltop the earth was hard with a black frost, and the air made me shiver through every limb." (Wuthering Heights, pg. 14). The characters that reside there have mostly negative characteristic as well, like Hindley, Heathcliffe, Hareton, Linton and Cathy Linton. Thrushcross Grange is at a contrast with Wuthering Heights because the home itself is described positively as being luxurious and beautiful. The characters that reside here are at a contrast with the characters from Wuthering Heights and have mostly positive characteristics, like Edgar, Catherine Earnshaw and Cathy Linton.
With this kind of contrast, it is no surprise that there is a place of neutrality from both extremes. The Moors is this place of neutrality, and it has always been described as being quiet and peaceful where people can share their true feelings. It was originally Catherine Earnshaw and Heathcliffe's getaway from all the anger and conflict. All that mattered to them was their love for each other, and while at the Moors, that's all that mattered to them. The way they could forget about their troubles shows the power of the Moors and its peaceful atmosphere. Each environment had a great power over its inhabitants, making the characters emotional and physical characteristics fit the mood of the environment itself..