Structural imbalance promotes behavior analogous to aesthetic preference in domestic chicks.
BACKGROUND
Visual images may be judged 'aesthetic' when their positioning appears imbalanced. An apparent imbalance may signify an as yet incomplete action or event requiring more detailed processing. As such it may refer to phylogenetically ancient stimulus-response mechanisms such as those mediating attentional deployment.


RESULTS
We studied preferences for structural balance or imbalance in week-old domestic chicks (Gallus gallus), using a conditioning procedure to reinforce pecking at either "aligned" (balanced) or "misaligned" (imbalanced) training stimuli. A testing phase with novel balanced and imbalanced stimuli established whether chicks would retain their conditioned behavior or revert to chance responding. Whereas those trained on aligned stimuli were equally likely to choose aligned or misaligned stimuli, chicks trained on misaligned stimuli maintained the trained preference.


CONCLUSIONS
Our results are consistent with the idea that the coding of structural imbalance is primary and even overrides classical conditioning. Generalized to the humans, these results suggest aesthetic judgments based upon structural imbalance may be based on evolutionarily ancient mechanisms, which are shared by different vertebrate species.
School of Psychology, National University of Ireland Galway, Galway, Republic of Ireland. mark.elliott@nuigalway.ie
Mark A
MA
Elliott
Orsola Rosa
OR
Salva
Paul
P
Mulcahy
Lucia
L
Regolin
D000818:Animals; D000829:Animals, Domestic; D000831:Animals, Newborn; D001522:Behavior, Animal; D002645:Chickens; D003214:Conditioning, Classical; D003213:Conditioning, Psychological; D005247:Feeding Behavior; D008297:Male; D010802:Phylogeny; D012054:Reinforcement, Psychology; D012931:Social Environment; D014785:Vision, Ocular