Theories differ on how typicality and arousal influence aesthetic appraisal and whether these processes together interact or have independent effects on aesthetic appraisal. This research investigates the simultaneous effects of typicality and arousal on aesthetic appraisal for product designs by manipulating both processes separately: typicality by prototype deviation and arousal by colour saturation levels. We demonstrate that typicality has a curvilinear relationship with aesthetic appraisal. Additionally, arousal has a positive linear relationship with aesthetic appraisal of product designs. Moreover, arousal can influence aesthetic appraisal independent from typicality. [ABSTRACT FROM AUTHOR] Copyright of British Journal of Psychology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)