An adaptive preference is a preference that is regimented in response to an agent’s set of feasible options. The fabled fox in the sour grapes story undergoes an adaptive preference change. I consider adaptive preferences more broadly, to include adaptive preference formation as well. I argue that many adaptive preferences that other philosophers have cast out as irrational sour-grapes-like preferences are actually fully rational preferences worthy of pursuit. I offer a means of distinguishing rational and worthy adaptive preferences from irrational and unworthy ones. The distinction is based on the agent’s own appraisal of the adaptive preference.