Causal Discounting

The first and foremost of my research foci is on causal discounting. Researchers have long known that when explaining events, individuals tend to prefer a single cause to multiple causes. For example, upon noticing that the lawn is wet, an individual is faced with several possible causes; it could have rained, or the sprinklers could have turned on. However, once it is clear that it did rain, the individual might consider it less likely that the sprinklers turned on, even though these causes are not mutually exclusive. The individual is discounting the possibility that the sprinklers caused the moisture. I investigate discounting in several domains.

Discounting of Fluency in Judgments

Perceptual fluency -- the ease with which an individual can process a piece of information -- influences a variety of judgments. (For information on my work on fluency, click here ). For example, items that are easily retrieved from memory are often judged to be occur more frequently in the real world. This makes sense, as items that are frequent are likely to be seen more often, and thus more easily remembered. However, there are many possible reasons that a piece of information could be processed fluently. If there is a salient cause for fluency aside from frequency (such as fame) will people engage in causal discounting and lower their estimation that the item is frequent? I have done a great deal of research on this topic, and found many examples of causal discounting. People discount for fame, proximity, personal relevance, and a variety of other reasons -- in each case they attribute their mental state of easy process to something other than frequency, and thus discount the possibility that the item could actually be frequent.

I am currently investigating possible cognitive mechanisms that might be used in discounting of mental states. Further, I'm looking into what processes people might use in retrieving possible causes for fluency. This is an extremely rich area of study, and will be the topic of my dissertation.

Discounting of Fluency Outside of Judgment

Demonstrations of discounting of fluency have, until now, been limited to the domain of judgment. However, I believe that since fluency plays a large roll in a variety of cognitive processes, discounting of fluency must do so as well. Therefore, I am investigating whether discounting of fluency occurs in other cognitive domains.

For example, studies by other researchers have demonstrated that fluency can play a role in categorical induction. That is, if I tell you a robin has sesimoid bones, you will be more likely to think that a penguin has sesimoid bones as well if you are easily able to process the concept of penguin. Since fluency plays a role in such inductions, the discounting of fluency should as well. A set of studies I'm running involves asking students to make inductions about their school mascot. The mascot should be available to all students which should make them more likely to make inductions to that animal. However students for whom the mascot has just been made salient should discount that fluency, and thus be less likely to make an induction.

Causal Discounting in Categorization

Categorization researchers are starting to realize that causal knowledge plays a large role in categorization. Thus, many researchers are moving away from more feature based theories, and towards theory based theories. If causal knowledge plays a role in categorization, then causal discounting should be observable given the correct situation. For example, if you see an animal that has four legs, a tail, and smells bad, you might be tempted to think it is a skunk. But if you learn that the animal has been wading in the sewers, you might attribute the unfortunate odor to the sewage, and discount the possibility that the smell is caused by "skunkness".

In fact, in a series of studies I have found just that. Additionally, I have found augmenting -- if the skunk has been wading in a flower bed, the influence of the stink is even greater. These findings support the notion that categorization is at least partially causal in nature, and poses a major challenge to many theories of categorization, which have trouble explaining the data. My collaborator Josh Tenenbaum and I are in the process of examining models of categorization to see which of them are capable of explaining these results.

Go back to my homepage.