Lessing's political knowledge appears throughout The Grass Is Singing, but most clearly in how she develops characters who represent various roles of farming in third world countries during the early twentieth century. Although Charlie Slatter is the successful farmer who takes over the land by the end of the story, sympathy is not directed toward him. Dick Turner appears as the tragic character who gains readers' sympathy because not only does he want to own the land but also because he defines his own self-worth by it. Both of these men, as are all white farmers of that time in that location, however, are hampered by their oppressive use of natives for labor.

Even though Dick Turner treats the natives more humanely than most, the injustices are enhanced by his wife's treatment of the natives. Oblivious to the ways of the farm and working with natives, Mary Turner enters her marriage and discovers how much she dislikes farming and the presence of natives. That Dick overlooks his wife's treatment of the natives indicates both marriage concerns and perpetuating practices of injustice.

Lessing further delineates the hierarchy of social order in this farming community by identifying the other farmer's interest in the outcome of the Turner's growing poverty. When Charlie insists that Dick leave the farm, the narrator tells readers that Charlie:

was fighting to prevent another recruit to the growing army of poor whites, who seem to respectable white people so much more shocking (though not pathetic, for they are despised and hated for their betrayal of white standards, rather than pitied) than all the millions of black people who are crowded into the slums or on the dwindling land reserves of their own country.

Because they do not follow the codes of the group and value the same things, their neighbors will not support the Turners.

Most of the novel seems to support a fatalistic view that regardless of his or her goals and desires, the individual will fold under the pressure of societal codes of conduct. Breaking out of them will eventually result in despair and disintegration of the individual. The demands of society will often lead to mental breakdown, as Marston realizes when he considers "What is madness but a refuge, a retreating from the world?"

That Mary recognizes too late that she has fallen into the same situation as her mother causes greater hopelessness and distance between them. As their spousal relationship grows more distant and they vie for power, Mary hides the changing interaction occurring between her and Moses, particularly as the ambiguous sexual undercurrent grows.

Throughout, Lessing threads together images from T. S. Eliot's The Waste Land, from which she quotes as the frontispiece of her book, but none so clearly as the last chapters as Mary loses touch with those around her and retreats into her dream world. Although always aggravated by the heat of the climate and the shrill sounds of the cicadas reminding her of nature about to overtake her own possession of the land, Mary's senses are enhanced as her personal disintegration occurs. The visual imagery of her dreams takes over until "her mind was filled with green, wet branches, thick wet grassland thrusting bushes." Just as Mary cannot prevent the grass of the veld and bush from overtaking her household, Dick, too, considers attempting to take more control by lighting the grass on fire during their last day on the farm as they prepare to leave. Tragically, at the end, Mary recognizes her erroneous ways and embraces her final annihilation.