Asymmetries in the perception of facial affect: is there an influence of reading habits?

Perceptions of happy facial affect from asymmetric composite faces presented in free vision were compared in four groups: left-to-right readers (Hindi), right-to-left readers (Arabic), left-to-right and right-to-left readers (Hindi/Urdu) and illiterates (Hindi/Urdu). Right- and left-handed users of Hindi and Urdu were studied. The analysis of asymmetry scores revealed a significant effect of Group, such that a left hemifield preference was present only in the left-to-right (Hindi) group. There were no reliable differences between right- and left-handers. Furthermore, the leftward bias was present in a significantly larger proportion of Hindi than Urdu or Arabic readers. These results are taken to reflect an interaction between a cerebral laterality effect and a directional scanning effect in facial affect judgment.