Visual preference for abstract curvature and for interior spaces: Beyond undergraduate student samples

Smoothly curved objects elicit feelings of pleasantness, and tend to be preferred over angular objects. Furthermore, individual differences (i.e., art expertise, openness to experience, holistic thinking), and the complexity of the stimuli are known to moderate the effect. We extended the study of individual differences to two theoretically-relevant groups. Study 1 compared liking for curvature in individuals with autism and a matched neurotypical control group (for age, gender and IQ). Because preference for curvature depends on both sensory (visuospatial) and affective input, for which individuals with autism exhibit anomalies, we hypothesized a difference in preference for curved stimuli between the two groups. Study 2 examined preference for curvature in a group of quasi-expert students of design. Because working architects and designers tend to regard curved interior spaces as beautiful, we hypothesized to replicate this effect within quasi-experts as well, thereby extending the effect across levels of expertise. Using an identical methodology across both studies, we administered abstract stimuli consisting of irregular polygons (angular vs. curved) and patterns of coloured lines (angular vs. curved), as well as concrete stimuli consisting of images of interior spaces. Preference for curvature was confirmed with abstract stimuli in all three groups. For interior design, the curvature effect diminished in magnitude, and this was especially evident in individuals with autism. Interestingly, quasi-experts preferred rectilinear over curvilinear interiors. We discuss the results in relation to the impact of individual differences and expertise on preference for curvature, and their implication for design studies in ecologically valid settings.