Which of the following is a characteristic of mental illness?

Perception is a key characteristic of mental illness because it encompasses the way an individual interprets and responds to their environment, which can be significantly altered in individuals experiencing mental health issues. For instance, those with certain mental illnesses may have distorted perceptions of reality, leading to challenges in functioning in everyday life. This altered perception can manifest in various ways, such as altered sensory experiences, misinterpretation of social cues, or delusional thoughts, all of which are common symptoms associated with mental health disorders.

The other options do not reflect characteristics typically associated with mental illness. Behavioral consistency suggests a reliable pattern of behavior, which may not be present in individuals experiencing mental health challenges. Financial stability generally pertains to an individual’s economic situation and doesn't directly relate to mental health symptoms. Social engagement involves interaction with others and can vary widely among individuals with mental illness, but is not a defining characteristic of mental health conditions themselves.