Knowledge that Transforms

Around the globe, negotiators often meet to divide a resource, barter goods, or make mutually beneficial trade-offs. In many cultures, negotiators “break bread” before negotiating by sharing food. Although breaking bread has biblical origins, it has come to symbolize shared eating as a pathway to increased cooperation. Building off this reasoning, Woolley and Fishbach (2019) empirically confirmed that shared eating leads to higher cooperation than separate eating. The present research conceptually replicated Woolley and Fishbach’s findings and extended them in fundamental ways. First, Woolley and Fishbach’s studies involved isolated, sequential decisions made with zero communication. Although their paradigm elegantly captured cooperation versus competition decisions, rarely do negotiations or decisions happen without any backand-forth communication. Therefore, we conducted two face-to-face negotiation experiments in which negotiators verbally and nonverbally communicated with each other and made decisions jointly. Furthermore, Woolley and Fishbach’s studies involved a single issue (e.g., strike days), whereas the negotiations in the present research involved eight issues, thus increasing the complexity of negotiating. The introduction of multiple issues not only makes the present negotiations closer to real-life negotiations but also enabled us to explore the efficient integration of resources, known colloquially as “expanding the pie” or “increasing joint gain” and known technically as Pareto efficiency. When a Pareto-efficient agreement is reached, “no [other] agreement is possible that would be preferred by both negotiators or would be preferred by one and to which the other would be indifferent” (Tripp & Sondak, 1992, p. 279). By focusing on face-to-face negotiations involving multiple issues, we explored whether prior shared-eating effects can be extended to more complex forms of human interactions that resemble most negotiations.

The visual system adapts to the environment, changing neural responses to aid efficiency and improve perception. However, these changes sometimes lead to negative consequences: If neurons at later processing stages fail to account for adaptation at earlier stages, perceptual errors result, including common visual illusions. These negative effects of adaptation have been termed the coding catastrophe. How does the visual system resolve them? We hypothesized that higher-level adaptation can correct errors arising from the coding catastrophe by changing what appears normal, a common form of adaptation across domains. Observers ( N = 15) viewed flickering checkerboards that caused a normal face to appear distorted. We tested whether the visual system can adapt to this adaptation-distorted face through repeated viewing. Results from two experiments show that such meta-adaptation does occur and that it makes the distorted face gradually appear more normal. Meta-adaptation may be a general strategy to correct negative consequences of low-level adaptation.

Humans have a unique ability to perceive shape in different ways. Although we naturally estimate objective (physical) shape in our daily interactions with the world, we are also capable of estimating projective (retinal) shape, especially when attempting to accurately draw objects and scenes. In four experiments, we demonstrated robust effects of 3D context on shape perception. Using a binocular stereo paradigm, we presented rectangular surfaces of varying widths alone or embedded in a polyhedron. We investigated how context, judgment type, and angle affected width estimates. We found that the presence of even a small amount of 3D context aids objective judgments but hinders projective judgments, whereas a lack of context had the opposite effect. Context facilitated objective shape assessments by improving estimates of surface orientation. These results demonstrate that the typical presence of 3D context aids shape perception (shape constancy) while simultaneously making the projective judgments necessary for realistic drawing more difficult.

= 5,484), we demonstrated that confidence in one's judgments decreases over a series of quantitative estimates. This finding was robust to various methods of confidence elicitation, the presence of incentives, and different estimation topics (Studies 1, 2, and 4). Our results also stand in contrast to participant expectations (Study 3). The phenomenon does not appear to be driven by fatigue, lack of effort, or various explanations based on incorporating uncertainty from prior judgments into subsequent ones. Our findings suggest that rather than evaluating confidence in isolation, participants evaluate confidence in reference to their stated confidence on earlier judgments. We theorize that confidence in earlier judgments increases in hindsight because of biased forgetting of disconfirming evidence. As a result, confidence in subsequent judgments appears to be comparatively lower (preregistered Studies 5-7). We discuss the implications for confidence research and consumer, organizational, and policy decision-making.

Choosing between candidates for a position can be tricky, especially when the selection test is affected by irrelevant characteristics (e.g., reading speed). One can correct for this irrelevant attribute by penalizing individuals who have unjustifiably benefited from it. Statistical models do so by including the irrelevant attribute as a suppressor variable, but can people do the same without the help of a model? In three experiments (total N = 357), participants had to choose between two candidates, one of whom had higher levels of an irrelevant attribute and thus enjoyed an unfair advantage. Participants showed a substantial preference for the candidate with high levels of the irrelevant attribute, thus choosing the less suitable candidate. This bias was attenuated when the irrelevant attribute was a situational factor, probably by making the correction process more intuitive. Understanding the intuitive judgment of suppressor variables can help candidates from underprivileged groups boost their chances to succeed.

Eyeblinks cause disruption of visual input that generally goes unnoticed. It is thought that the brain uses active suppression to prevent awareness of the gaps, but it is unclear how suppression would affect the perception of dynamic events when visual input changes across the blink. Here, we addressed this question by studying the perception of moving objects around eyeblinks. In Experiment 1 ( N = 16), we observed that when motion terminates during a blink, the last perceived position is shifted forward from its actual last position. In Experiment 2 ( N = 8), we found that motion trajectories were perceived as more continuous when the object jumped backward during the blink, canceling a fraction of the space that it traveled. This suggests subjective underestimation of blink duration. These results reveal the strategies used by the visual system to compensate for disruptions and maintain perceptual continuity: Time elapsed during eyeblinks is perceptually compressed and filled with extrapolated information.

Reduced attentional control with age is associated with the processing and maintenance of task-irrelevant information in memory. Yet the nature of these memory representations remains unclear. We present evidence that, relative to younger adults ( n = 48), older adults ( n = 48) both (a) store simultaneously presented target and irrelevant information as rich, bound memory representations and (b) spontaneously reactivate irrelevant information when presented with previously associated targets. In a three-stage implicit reactivation paradigm, re-presenting a target picture that was previously paired with a distractor word spontaneously reactivated the previously associated word, making it become more accessible than an unreactivated distractor word in a subsequent implicit memory task. The accessibility of reactivated words, indexed by priming, was also greater than the degree of distractor priming shown by older adults in a control condition ( n = 48). Thus, reduced attentional control influences the processing and representation of incoming information.