The question of “what makes two things similar” is of fundamental importance to cognitive psychology… Our research suggests that perceptual similarity is highly related to general cognition. Perceptual similarity is quite sophisticated, and vestiges of perceptual similarity can be found in higher-level cognition.
One of the reasons why similarity is able to provide the underpinnings for many cognitive processes is that perception itself is sophisticated and flexible. Our empirical research and computational modeling efforts have indicated that when people evaluate similarity they carry out a process not unlike analogical reasoning…
A second reason why similarity is smart enough to be useful in explaining cognition is that it is adaptive and context-sensitive… [S]imilarity is constructed for particular purposes and circumstances rather than memorized. Objects do not have fixed similarities that people simply uncover; it would be more accurate… to say that “people similaritize objects.”
Perceptual similarity may be a useful notion in understanding high-level cognition because [similarity] is sophisticated… [and] “high-level” cognition is not always very high-level. In many cases, perceptual similarity intrudes on categorization and decision making even when it is inappropriate or irrelevant…
Taken in total, this research argues that similarity plays a role even in highly symbolic processes because it is flexible enough to provide the groundwork for many cognitive processes, yet constrained enough to provide non-circular explanations for these cognitive processes.
Rob Goldstone | Making comparisons: Similarity, analogy, and translating between conceptual systems
Rob Goldstone | Precepts and Concepts Laboratory: Interactions between perceptual and conceptual learning