Individuals’ preferences for environmental stimuli bear significantly on their responses to behavioral assessment and intervention. In this study, we assessed the relationship between participants’ history of access to preferred stimuli and changes in preference for those stimuli over time. For three participants, we conducted preference assessments in multiple formats to identify similarly (moderately) preferred stimuli. We then randomly assigned these stimuli to one of the following conditions: (a) free access, (b) denied access (i.e., items were routinely presented and then taken away), or (c) hidden (i.e., out of view). Following extended exposure to these conditions (60–75 days), we repeated preference assessments using the same formats and stimuli. All three participants demonstrated an increased preference for stimuli with a history of denied access. For one participant, a progressive ratio reinforcer assessment indicated similar shifts in reinforcing efficacy across conditions. We discuss the implications of these findings in relation to prominent cognitive and behavioral explanations, respectively.