The quantification of smiling using a microcomputer-based approach

This study examines the relationship between the ratings made of a set of smiling and neutral expressions and the facial features which influence these ratings. Judges were shown forty real face photographs of smile and neutral expressions and forty line drawings derived from these photographs and were asked to rate the degree of smiling behavior of each expression. The line drawings of the face were generated by a microcomputer which utilizes a mathematical model to quantify facial expression. Twelve facial measures were generated by the computer. Significant differences were found between the ratings of smile and neutral expressions. The Mode of Presentation did not contribute significantly to the ratings. Using the facial measures as separate covariates, five mouth measures and one eye measure were found to discriminate significantly between the ratings made on smile and neutral expressions. When entered as simultaneous covariates, only four mouth measures contributed to the differences found in the expression ratings. Future research projects which may utilise the computer model are discussedThe research reported in this paper was conducted in the Department of Psychology, University of Adelaide. The authors would like to thank Ulana Sudomlak for her assistance in the gathering and recording of the data for this project, and the reviewers for their helpful comments on an earlier version of this paper.