Passive-aggressive behavior occurs when a person’s apparent willingness to agree to the needs or requests of others actually masks a seething resentment and desire to quietly resist. 

People who are passive-aggressive resent, oppose and resist the demands of others to function in certain ways. They struggle to express anger verbally and directly, and instead channel their resentment into behavior such as procrastination, inefficiency or forgetfulness that allows them to avoid completing projects. They tend to feel cheated, underappreciated and misunderstood. Often, they chronically complain to others and refuse to accept blame for their mistakes.

In many cases, a person who is passive-aggressive may espouse enthusiasm when asked to do something, but then will sabotage their actions by performing them too late or in a way that is not helpful. For example, a person who has received material to review may pretend to lose the file rather than directly tell a supervisor there is not enough time to complete the project.

Passive-aggressive behavior can occur in most situations, but is most common in supervisor/employee, teacher/student and personal relationships. People who are passive-aggressive tend to have a strong dislike of authority.

Because people prone to passive-aggressive behavior tend to bottle up their anger, they may experience health problems such as headaches, stress, depression or high blood pressure. In addition, several personality disorders are closely associated with passive-aggressive behavior, including: 

• Borderline personality disorder (BPD)
• Histrionic personality disorder
• Paranoid personality disorder
• Dependent personality disorder
• Antisocial personality disorder
• Avoidant personality disorder (APD)

Cultural differences may sometimes be misinterpreted as passive-aggressive behavior. For example, in some cultures, it is considered impolite to directly disagree with a person. In these cases, a worker may indicate they will perform a task (even when they know it is impossible) rather than refuse to do so. Then the worker leaves the task undone without an explanation.

The exact causes of passive-aggressive behavior remain unknown. However, like other recognized personality disorders, it may involve a combination of genetic and environmental factors. The problems with authority may be rooted in a child’s struggle with parental authority. Families or societies that do not recognize normal expressions of anger may contribute to the development of passive-aggressive behavior. If a person's first exposure to authority figures was unsatisfying, erratic or ambivalent, the result might be passive-aggressive behavior. It appears also that some components of personality disorders might be inherited.