One way to make judgments under uncertainty is to anchor on information that comes to mind and adjust until a plausible estimate is reached. This anchoring-and-adjustment heuristic is assumed to underlie many intuitive judgments, and insufficient adjustment is commonly invoked to explain judgmental biases. However, despite extensive research on anchoring effects, evidence for adjustment-based anchoring biases has only recently been provided, and the causes of insufficient adjustment remain unclear. This research was designed to identify the origins of insufficient adjustment. The results of two sets of experiments indicate that adjustments from self-generated anchor values tend to be insufficient because they terminate once a plausible value is reached (Studies 1a and 1b) unless one is able and willing to search for a more accurate estimate (Studies 2a-2c).