What mindset is characterized by believing the worst of human nature and motives?

The mindset characterized by believing the worst of human nature and motives is indeed cynical. Cynicism involves a deep skepticism regarding the integrity and motives of others, leading to a belief that people are primarily driven by self-interest. Individuals with a cynical perspective often question the sincerity of others' actions and motives, assuming deceit or ulterior intentions behind seemingly altruistic behavior.

This attitude can stem from personal experiences or broader societal observations that reinforce a belief in the inherent negativity of people. It's a viewpoint that erodes trust and can lead to a sense of disillusionment with humanity as a whole. In the context of the other options, while pessimism may reflect a general sense of negativity about outcomes, it doesn't specifically focus on the motives of individuals. Nihilism, on the other hand, suggests a belief in the meaninglessness of life rather than a judgment about human motives. Optimism is characterized by a hopeful outlook, which contradicts the fundamental tenets of cynicism. Therefore, the identification of cynicism as the correct answer aligns perfectly with the idea of believing the worst of human nature and motives.