Overcoming bias is the overarching theme of The Jacket, and the novella examines how the biases we hold affect how we think about and act toward those around us. Implicit bias, also known as implicit prejudice or implicit attitude, is a pattern of unconscious negative assumptions we make about a specific social group, such as a certain race or gender. Implicit bias is part of implicit social cognition, the idea that attitudes, perceptions, and stereotypes may be triggered without conscious thought. Implicit processes are shaped by our environment, our upbringing, and our experiences. They are solidified by subconscious connections made between the social group and characteristics we are taught to associate with members of that group. The Jacket explores implicit bias in regard to race, specifically how Phil (a white kid) is implicitly biased against Daniel (a Black kid) based on perceptions that Black people are more prone to crime and less trustworthy than white people.

Since implicit bias occurs without conscious input, holding such biases does not necessarily mean someone is prejudiced against a group. The human brain is constantly receiving more information than it can handle, so, to keep itself functioning in a way that allows us to survive, it categorizes information based on what we think we know.