1. the level of everyday performance of tasks that is required for a person to fulfill typical roles in society, including maintaining independence and meeting cultural expectations regarding personal and social responsibility. Specific categories in which adaptive behavior is usually assessed include self-help, mobility, health care, communication, domestic skills, consumer skills, community use, practical academic skills, and vocational skills. Limitations in adaptive behavior are one of the criteria for diagnosis or classification of intellectual disability and for determining legal competence.

2. any behavior that enables an individual to adjust to the environment appropriately and effectively. It is often discussed in the context of evolution. See also adjustment process.