Throughout A Grain of Wheat, the author shows how guilt shapes the characters’ attitudes toward betrayal and loyalty in political, cultural, and individual terms. The ways that guilt and betrayal intersect are most clearly revealed through the character of Mugo. His fear of punishment, in the form of incarceration in the prison camp, was so intense that he betrayed Kihika to save himself. Mugo lacked both political convictions and the courage to keep secret his knowledge that Kihika had killed the British district officer. Instead, he informed on his long-time rival. Guilt finally caused him to confess, resulting in his own death.

Betrayal as the combination of personal and political motivations is expressed in the character of Karanja. His actions are based partly in the desire for advancement and power, but he partly succeeds in rationalizing his behavior. He wants to believe that the corrupt system he supports is preferable to the chaos of revolution. Karanja betrays his own people by being complicit with the injustices that the British perpetrate. Becoming the colonial-supported chief fuels his frustrations and provokes him to further acts of cruelty. His overall betrayal of his fellow Kenyans is represented in his abusive behavior toward women, especially his rape and domination of Mumbi.