Martha is definitely one of the most vicious characters in the history of dramatic literature. She drives most the action of the play by launching assault after assault on her husband George. (Not that he doesn't get in a few licks of his own.) Time and again Martha takes it one step farther. Over the course of the play she exposes the failure of his career, his novel, and even his traumatic childhood. On top of that she makes a blatant attempt at infidelity right in his bed. Where, oh where does all this meanness come from?
First there's the fact that she's an alcoholic. With the amount of gin Martha guzzles during the play it's surprising she's not flat on her face by the end of Act 3. George pokes at her about this constantly. Of course, that doesn't stop him from enabling her habit by making her one drink after another. Undoubtedly, Martha's constant state of intoxication greases the wheels for some of her crueler exploits. We wonder, though, why she began drinking. In one poignant moment Martha says to herself:
"I cry allllll the time; but deep inside, so no one can see me. […] And Georgie cries all the time, too. […] we take our tears, and we put 'em in the icebox, in the goddamn ice trays […] and then we put them…in our…drinks." (3.1)
These occasional moments of vulnerability help us to see beyond Martha's cruel exterior. It makes us think that there's probably some deep sadness driving her drinking and emotional brutality. But what could that sadness be?
The obvious answer would be the thing she complains about for the entire play: her marriage to George. At one point she yells at him:
"It went snap tonight at Daddy's party. […] I watched you sitting there, and I watched the younger men around you, the men who were going to go somewhere. […] and you weren't there!" (2.668)
Martha had high hopes for George's academic career. Unfortunately, it's gone absolutely nowhere, leaving her bitter and disillusioned. It's quite possible that she was hoping to live vicariously through him as he rose through the ranks at the university. Women weren't typically allowed careers at the time when this play was set, and perhaps Martha was hoping to have something of a career through her husband. This must have been a tough reality for a woman like Martha. Whatever her faults, she's both capable and intelligent. She'd probably do well in the academic world. Perhaps Martha is so angry all the time because society has trapped her in the ill-fitting role of housewife. Watching her husband flop time and again must be incredibly frustrating.
There also seems to be an even deeper source of Martha's dissatisfaction with George. At the beginning of Act 3, after her attempted infidelity with Nick, Martha admits to Nick that George is the only man who's ever made her happy. She goes on to say that George "has made the hideous, the hurting, the insulting mistake of loving me and must be punished for it" (3.45). This seems to suggest that Martha's main problem with George is the fact that he truly loves her. She adds that her husband "tolerates, which is intolerable; […] is kind, which is cruel" (3.47).
Yes, it looks like Martha hates herself so much that it's impossible for her to accept love from another person. No wonder she acts the way she does. She's trapped in a tragic web of love and hate from which there seems to be no escape. She probably sums up her situation best when she says: "George and Martha: sad, sad, sad" (3.45).