small to see, such as an atom. Affordances Gibson coined the noun affordance. For Gibson the noun affordance pertains to the environment providing the opportunity for action. Affordances require a relationship in which the environment and the animal can work together. An example is that mankind has changed the environment to better suit our needs. When coming across Earth's natural steep slopes, man designed stairs in order to afford walking. In addition, objects in the environment can also afford many different behaviors, such as lifting or grasping. Gibson argued that when we perceive an object we observe the object's affordances and not its particular qualities. He believed that perceiving affordances of an object is easier than perceiving the many different qualities an object may have. Affordances can be related to different areas of the habitat as well. Some areas of the world allow for concealing while some allow for foraging. Legacy James J. Gibson left a lasting impact on the way that psychologists and philosophers conceptualize perception and action. He rejected the behaviorists' assumptions that learning involves the formation of associations between stimuli and responses, adopting instead a holistic view related to that of the Gestalt psychologist Kurt Koffka with whom he had contact. He argued that the perceived environment is not composed by stitching together such elements as shapes and edges, but rather that the world is made up of meaningful features that are experienced continuously as wholes. He will perhaps be best remembered for his theory of affordances, which some theorists have suggested provides a fundamental way to understand the duality of mind and external reality. Previous theories of sensory meaning have argued that perceptions are separate and private from one another. This stance placed all of the perceptive meaning on the individual, which meant there was no way to find common ground on individuals' shared experiences. Gibson contended that when stimulus information is being sought out, meaningful properties of that stimulus are also perceived relationally. For instance, a softball affords "throwing" if the observer notices that the ball fits well in a person's hand, and that the weight allows it to be thrown. The training of aviators is a practical application of Gibson's views, which such suggest that training should be as realistic and unconstrained as possible. Gibson's work indicates the interactivity of observers and the natural environment, and has been dubbed ecological psychology as a result.