<p>This paper presents an original experiment to test a key prediction of the personalist rationale for copyright, which argues that intellectual property is morally justified because creative works are extensions of the creator’s personality. According to this theory, people should adhere more strongly to copyright when a creation reflects a higher degree of personal content. To test this, a theft game was designed where participants could steal or refrain from stealing creative works with varying levels of “personality”. The results show a treatment effect only among participants with a strong preference for intellectual property rights. This study is the first to experimentally investigate the personalist theory of intellectual property. Although preliminary, these findings contribute to debates on intellectual property policy, such as the protection of AI-generated creations. The experimental protocol used also offers new research opportunities on intellectual property and creativity.</p>