Guest Blog Post by Dr. Katherine May, Ed.D., BCBA
Once a tact has been established, the tact response can occur under novel stimulus conditions through the process of stimulus generalization. In other words, there are many ways to label one stimuli. Skinner (1957) identifies four different levels of generalization based on the degree to which novel stimuli share the relevant or defining features of the original stimulus. These four types of tact extensions are generic, metonymical, solistic, and metaphorical.
Generic Tact Extension: A tact evoked by a novel stimulus that shares all of the relevant or defining features associated with the original stimulus.
Example: For generic tact extensions it’s easiest to think of stimulus generalization. An example would be seeing a Dunkin Donuts and then seeing Starbucks and labeling them both a coffee shop. This would be one response for both stimuli.
Metonymical Tact Extension: A tact evoked by a novel stimulus that shares none of the relevant features of the original stimulus configuration, but some irrelevant yet related feature has acquired stimulus control.
Some examples include seeing an empty cup and saying “water” or seeing a black cat and later calling black kettle “cat.” In these scenarios the client made some associations between the two stimuli even though they do not share any of the relevant features of the original stimulus.
SolisticTact Extension: A verbal response evoked by a stimulus property that is only indirectly related to the proper tact relation. An example of this would be the use of “slang” language.
For example if you walk into someone and say “Oh Goodness, I am so sorry,” and they respond back, “you good” instead of saying “that’s okay” or “no problem.” Another example would be saying something along the lines of “I ain’t got no time for that.” This is slang language which is used in place of proper language to relay the same meaning.
Metaphorical Tact Extension: A tact evoked by a novel stimulus that shares some, but not all, of the relevant features of the original stimulus. Essentially this simply means using metaphors.
Some examples would be saying a “test was as easy as pie” or “time is money.”
Cooper, J. O., Heron, T. E., & Heward, W. L. (2019). Applied Behavior Analysis (3rd Edition). Hoboken, NJ: Pearson Education.