It is important to note that stimulus objects always operate on the basis of functions that are acquired through historical contacts with organisms. Each object or person acquires one or many functions. These functions pertain to use, like, dislike, ownership, and so on. Persons take on many functions, including being liked or disliked, being pleasant or unpleasant, being clever or stupid, or being helpful or indifferent. Similarly, objects take on a variety of functions.
Tables are objects on which to place things, as chairs are objects for sitting.
Particular foods do or do not become good to taste or entirely inedible. In general, there are developed an infinite number of discriminative functions. Many correlate with reactions of fear and loathing, loving or hating, and numerous other affective reactions. Since psychological organisms are at the same time organismic and inorganic entities, they and their behaviors are subject to the same conditions as the events of biology, physics, and chemistry. But in addition, psychological fields are characterized by unique circumstances.