The uncertainty response has been influential in studies of human perception, and it is crucial in the growing research literature that explores animal metacognition. However, the uncertainty response's interpretation is still sharply debated. The authors sought to clarify this interpretation using the dissociative technique of cognitive loads imposed on ongoing discrimination performance. Four macaques (Macaca mulatta) performed a sparse-dense discrimination within which an uncertainty response let them decline difficult trials or a middle response let them identify middle stimuli. Concurrent memory tasks were occasionally overlain on ongoing discrimination performance. The concurrent tasks disrupted macaques' uncertainty responses far more than their sparse, middle, or dense discrimination responses. This dissociation suggests that the uncertainty response is a higher level decisional response that is particularly dependent on working memory and attentional resources. This is consistent with the theoretical possibility that the uncertainty response is an elemental behavioral index of uncertainty monitoring or metacognition.

Some studies of nonhuman animals' metacognitive capacity encourage competing low-level, behavioral descriptions of trial-decline responses by animals in uncertainty-monitoring tasks. To evaluate the force of these behavioral descriptions, the authors presented 6 capuchin monkeys (Cebus apella) with 2 density discrimination tasks between sparse and dense stimuli. In one task, difficult trials with stimuli near the middle of the density continuum could be declined through an "uncertainty" response. In the other task, making a "middle" response to the same stimuli was rewarded. In Experiment 1, capuchins essentially did not use the uncertainty response, but they did use the middle response. In Experiment 2, the authors replicated this result with 5 of 6 monkeys while equating the overall pace and reinforcement structure of the 2 tasks, although 1 monkey also showed appropriate use of the uncertainty response. These results challenge a purely associative interpretation of some uncertainty-monitoring performances by monkeys while sharpening the theoretical question concerning the nature of the psychological signal that occasions uncertainty responses.

Some metacognition paradigms for nonhuman animals encourage the alternative explanation that animals avoid difficult trials based only on reinforcement history and stimulus aversion. To explore this possibility, we placed humans and monkeys in successive uncertainty-monitoring tasks that were qualitatively different, eliminating many associative cues that might support transfer across tasks. In addition, task transfer occurred under conditions of deferred and rearranged feedback-both species completed blocks of trials followed by summary feedback. This ensured that animals received no trial-by-trial reinforcement. Despite distancing performance from associative cues, humans and monkeys still made adaptive uncertainty responses by declining the most difficult trials. These findings suggest that monkeys' uncertainty responses could represent a higher-level, decisional process of cognitive monitoring, though that process need not involve full self-awareness or consciousness. The dissociation of performance from reinforcement has theoretical implications concerning the status of reinforcement as the critical binding force in animal learning.

The Cognitive Reflection Test (CRT) is a measure of analytical reasoning that cues an intuitive but incorrect response that must be rejected for successful performance to be attained. The CRT yields two types of errors: Intuitive errors, which are attributed to Type 1 processes; and non-intuitive errors, which result from poor numeracy skills or deficient reasoning. Past research shows that participants who commit the highest numbers of errors on the CRT overestimate their performance the most, whereas those with the lowest error-rates tend to slightly underestimate. This is an example of the Dunning-Kruger Effect (DKE). The present study examined how intuitive vs. non-intuitive errors contribute to overestimation in the CRT at different levels of performance. Female undergraduate students completed a seven-item CRT test and subsequently estimated their raw score. They also filled out the Faith in Intuition (FI) questionnaire, which is a dispositional measure of intuitive thinking. Data was separated into quartiles based on level of performance on the CRT. The results demonstrated the DKE. Additionally, intuitive and non-intuitive errors predicted miscalibration among low, but not high performers. However, intuitive errors were a stronger predictor of miscalibration. Finally, FI was positively correlated with CRT self-estimates and miscalibration, indicating that participants who perceived themselves to be more intuitive were worse at estimating their score. These results taken together suggest that participants who perform poorly in the CRT and also those who score higher in intuitive thinking disposition are more susceptible to the influences of heuristic-based cues, such as answer fluency, when judging their performance.