The Robustness of Anchoring in a Naturalistic VR-Based Task.

Anchoring occurs when a quantitative estimate is biased toward an initially presented value (the anchor). Anchoring occurs both in high-level explicit estimation of numeric quantities and in lower-level perceptual tasks and persists even when reliable information about the quantity being estimated is directly available at the point of judgment. This suggests anchoring might derive from generic processing underpinning estimation. Such tasks, however, are almost exclusively lab-based, and the information required to complete the task is rarely available to the participant in a way that reflects how such information is sampled in real-life. To address this, across two experiments, we immersed participants in a virtual world on a platform that could be placed at any height. After an anchor was presented, participants subsequently estimated their height naturally, by interpreting sensory and cognitive cues from the 3D environment in which they were immersed. We manipulated the amount of information directly available to the participant for making their judgment as well as the offset between the anchor and the actual height. To modulate the extent to which task-relevant information was acquired naturally from the environment, we also contrasted anchoring effects in and out of VR. Although participants clearly used the available perceptual and cognitive information to make height estimates, anchoring effects were evident, displayed similar properties to those reported in previous lab-based studies, and were consistent both in and out of VR. Our design also allowed us to recover a novel subjective anchoring measure that facilitated a particularly parsimonious descriptive model of our anchoring data. We conclude that anchoring is a generic feature of all estimation tasks, even when task-relevant information is acquired naturally, as in real-life estimation. These results emphasize the potential for this cognitive bias to have a significant impact on performance in any real-world task requiring quantitative estimation.