Because any feature of an occasion may gain some control over a response reinforced on that occasion, it is possible for irrelevant stimulus features to gain control of a response. For example, in the United States, it is often reported by the press that a statement was issued “by the White House.” Skinner says this type of extension occurs because the stimulus frequently accompanies the relevant features.
An instance of verbal behavior with the following features:
The response form has already been acquired in one or more of the elementary verbal relationships
The stimulus must be novel
The novel stimulus must have none of the relevant features of the class of stimuli that previously controlled the response
The type of elementary verbal relationship
Formal and dynamic characteristics of both the stimulus and the response
Whether or not the current response is followed by reinforcement