[DSRP Evidence](https://dsrpevidence.org/) # The Adaptive Nature of Human Categorization ## Details **Authors** Anderson **Year** 1991 **Publisher** Psychological Review **Discipline** Cognitive Science [Read it at the publisher](https://doi.org/10.1037/0033-295x.98.3.409) 10.1037/0033-295x.98.3.409 ## In authors' words ### Abstract A rational model of human categorization behavior is presented that assumes that categorization reflects the derivation of optimal estimates of the probability of unseen features of objects. A Bayesian analysis is performed of what optimal estimations would be if categories formed a disjoint partitioning of the object space and if features were independently displayed within a category. This Bayesian analysis is placed within an incremental categorization algorithm. The resulting rational model accounts for effects of central tendency of categories, effects of specific instances, learning of linearly nonseparable categories, effects of category labels, extraction of basic level categories, base-rate effects, probability matching in categorization, and trial-by-trial learning functions. Al-though the rational model considers just I level of categorization, it is shown how predictions can be enhanced by considering higher and lower levels. Considering prediction at the lower, individual level allows integration of this rational analysis of categorization with the earlier rational analysis of memory (Anderson & Milson, 1989). Anderson (1990) presented a rational analysis ot 6 human cog-nition. The term rational derives from similar "rational-man" analyses in economics. Rational analyses in other fields are sometimes called adaptationist analyses. Basically, they are ef-forts to explain the behavior in some domain on the assump-tion that the behavior is optimized with respect to some criteria of adaptive importance. This article begins with a general char-acterization ofhow one develops a rational theory of a particu-lar cognitive phenomenon. Then I present the basic theory of categorization developed in Anderson (1990) and review the applications from that book. Since the writing of the book, the theory has been greatly extended and applied to many new phenomena. Most of this article describes these new develop-ments and applications. A Rational Analysis Several theorists have promoted the idea that psychologists might understand human behavior by assuming it is adapted to the environment (e.g., Brunswik, 1956; Campbell, 1974; Gib- ### What they set out to do (purpose) To explore how categorization functions within the human mind and adapts to contextual situations. ### What they found (results) Categorization of the elements of the problem is an essential step towards building a complete frame. He listed three origin points of category formation: linguistic, feature overlap, similar function. The origin of categorization does not have to be one of these, but can be all three of them. Categorization behavior can be predicted from the structure of the environment at least as well as it can from the structure of the mind. ## Commentary ### In short While categorization is an important process to study, it is not the most fundamental process to study, because it is not a universal pattern of mind such as part-whole systems. ### In more detail Anderson (1991) analyzed the adaptive nature of human categorization. In framing a cognitive problem, Anderson noted that categorization of the elements of the problem is an essential step towards building a complete frame. He listed three origin points of category formation: linguistic, feature overlap, similar function. These three origin points (alone or together) make up the perspective that frames and subsequently forms the category. When categorizing, linguistics are derived from the label of the object. For example, all of the things below are grouped because they start with the letter O, Ostrich, Orange, Octopus, Octagon, etc. Feature overlap occurs when we identify similar physical or conceptual features in a group of objects. As shown below, these objects are grouped into a category as "all red objects." It might be helpful to think of categories using a metaphor like a bouncer at a night club. When we form categories, we create a frame (using a perspective) which decides what objects get into the club and which ones don't. In the case above, you only get into the club if you start with the letter “O.” The bouncer is the perspective that creates the category. Finally, Anderson identifies categories based on similar function by simply grouping objects that function similarly, as shown by the musical instruments below. The origin of categorization does not have to be one of these, but can be all three of them. He goes on to conclude that, “categorization behavior can be predicted from the structure of the environment at least as well as it can from the structure of the mind.” In other words, the mind naturally categorizes the world around it, and the Systems pattern is therefore embedded into the very nature of thought itself. Understanding part-whole systems will give insight into this fundamental aspect of our cognition. Note also that DSRP (in this case specifically S and P) shows us that Anderson's three originating points for a category (feature overlap, linguistics, and similar function) are somewhat arbitrary and not complete, as absolutely anything could be used as the framing perspective that leads to a category forming, such as: how objects make you feel, color (not a feature of object but an interaction effect), random assignment, sounds you might associate with the object(s), etc. **Patterns it shows** S **How to cite this** Anderson (1991). The Adaptive Nature of Human Categorization. Psychological Review.