This study examined the aesthetics of interactive objects (IOs), which are three-dimensional physical artefacts that exhibit autonomous behaviour when handled. The aim of the research was threefold: first, to investigate whether aesthetic preference for distinctive objects' structures emerges in compound stimulation; second, to explore whether there exists aesthetic preference for distinctive objects' behaviours; and, finally, to test whether there exists aesthetic preference for specific combinations of objects' structures and behaviours. The following variables were systematically manipulated: (a) IOs' contour (rounded vs angular), (b) IOs' size (small vs large), (c) IOs' surface texture (rough vs smooth), and (d) IOs' behaviour (lighting, sounding, vibrating, and quiescent). Results show that behaviour was the dominant factor: it influenced aesthetics more than any other characteristic; vibrating IOs were preferred over lighting and sounding IOs, supporting the importance of haptic processing in aesthetics. Results did not confirm the size and smoothness effects previously reported in vision and touch, respectively, which suggests that the aesthetic preference that emerges in isolated conditions may be different in compound stimulation. Results corroborate the smooth curvature effect. We suggest that behavior may be an aesthetic primitive.