Functionality forms the basis for how people develop affection for others and things. Performing functions for others creates a sense of indebtedness and gratitude in the recipient, fostering temporary affection. This principle applies not just to human relationships but also how we value functional animals, households, lifestyles, and art that serves practical purposes. In business, serving customers through valuable functions is key to a company's success, as reputation is tied to functionality. Employee drug screening serves important functions by bolstering reputation, setting clear standards, and addressing problems.