Which of the following is an example of a positive symptom of schizophrenia?

A positive symptom of schizophrenia refers to an excess or distortion of normal functions—essentially symptoms that reflect an addition to the person's experiences. Hallucinations, which are sensory perceptions that occur without an external stimulus, such as hearing voices or seeing things that aren't there, fit this definition perfectly. They represent an abnormal cognitive experience that is not typically present in a mentally healthy individual.

In contrast, flat affect, apathy, and withdrawal are considered negative symptoms of schizophrenia. These symptoms represent a decrease or loss of normal functions, such as emotional expression (flat affect), motivation (apathy), or social engagement (withdrawal). Negative symptoms often lead to significant challenges in daily functioning and can hinder a person's ability to connect with others and participate in life normally.

Thus, the correct identification of hallucinations as a positive symptom underscores the characteristic nature of that symptom—an enhancement of mental processes leading to experiences that are outside the norm.