Behavior modification is a type of therapy or treatment that focuses on changing unwanted or problematic behaviors through the use of positive or negative reinforcement. The goal of behavior modification is to replace negative or maladaptive behaviors with more positive, adaptive ones, in order to improve an individual's overall functioning and quality of life.

The principles of behavior modification are based on the idea that behavior is shaped by the consequences that follow it. Positive reinforcement, such as rewards or praise, can be used to encourage desired behaviors, while negative reinforcement, such as punishment or the removal of privileges, can be used to discourage unwanted behaviors.

Behavior modification techniques have been used to address a variety of issues, including substance abuse, anxiety, depression, and attention-deficit/hyperactivity disorder (ADHD). Examples of behavior modification techniques include token economies, in which individuals earn tokens or rewards for positive behaviors, and systematic desensitization, in which individuals are gradually exposed to feared stimuli in a safe and controlled environment.

Behavior modification is often used in conjunction with other forms of therapy or treatment, and may be tailored to the individual needs and goals of each client. It can be a highly effective approach for achieving lasting behavior change, particularly when used in a supportive and collaborative therapeutic relationship.