title: Differences in the Visual Perception of Symmetric Patterns in Orangutans (Pongo pygmaeus abelii) and Two Human Cultural Groups: A Comparative Eye-Tracking Study.
abstract: Symmetric structures are of importance in relation to aesthetic preference. To investigate whether the preference for symmetric patterns is unique to humans, independent of their cultural background, we compared two human populations with distinct cultural backgrounds (Namibian hunter-gatherers and German town dwellers) with one species of non-human great apes (Orangutans) in their viewing behavior regarding symmetric and asymmetric patterns in two levels of complexity. In addition, the human participants were asked to give their aesthetic evaluation of a subset of the presented patterns. The results showed that humans of both cultural groups fixated on symmetric patterns for a longer period of time, regardless of the pattern's complexity. On the contrary, Orangutans did not clearly differentiate between symmetric and asymmetric patterns, but were much faster in processing the presented stimuli and scanned the complete screen, while both human groups rested on the symmetric pattern after a short scanning time. The aesthetic evaluation test revealed that the fixation preference for symmetric patterns did not match with the aesthetic evaluation in the Hai//om group, whereas in the German group aesthetic evaluation was in accordance with the fixation preference in 60 percent of the cases. It can be concluded that humans prefer well-ordered structures in visual processing tasks, most likely because of a positive processing bias for symmetry, which Orangutans did not show in this task, and that, in humans, an aesthetic preference does not necessarily accompany the fixation preference.
authors.affiliation: Department of Education and Psychology, Freie Universität Berlin Berlin, Germany.
authors.forename: Cordelia
authors.initials: C
authors.lastname: Mühlenbeck
authors.affiliation: Department of Education and Psychology, Freie Universität Berlin Berlin, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Liebal
authors.affiliation: Department of Education and Psychology, Freie Universität BerlinBerlin, Germany; Graduate School "Languages of Emotion," Freie Universität BerlinBerlin, Germany.
authors.forename: Carla
authors.initials: C
authors.lastname: Pritsch
authors.affiliation: Experimental Psychology Unit, Helmut Schmidt University - University of the Federal Armed Forces Hamburg Hamburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jacobsen
keywords: Orangutans; aesthetic preference; cultural comparison; eye tracking; symmetry