Behavioral
Part of speech: adjective
Definition: of or related to behavior
Example sentence: My mother's father was the behavioral psychologist, John B. Watson.
Activity
Part of speech: noun
Definition: The state or quality of being active; nimbleness; agility; vigorous action or operation; energy; active force; as, an increasing variety of human activities.something done as an action or a movementsomething done for pleasure or entertainment, especially one involving movement or an excursion.Use (of internet, playstation, bank account etc.)
Example sentence: It makes no sense to worry about things you have no control over because there's nothing you can do about them, and why worry about things you do control? The activity of worrying keeps you immobilized.