The Orangutan Facial Action Coding System (OrangFACS) is an observational tool for identifying and coding facial expressions in Orangutans. It has been adapted from the original FACS system created by Ekman and Friesen (1978).
Since the original version FACS has been successfully adapted for several primate species, such as Chimpanzees (Vick et al., 2007), Macaques, (Parr et al., 2010) and Gibbons (Waller et al., in prep.; Burrows et al., 2011). The extensive similarities in facial musculature between humans and other primates are what makes these adaptations possible and were crucial in the development of OrangFACS.
The resulting OrangFACS Manual is an objective and reliable tool which is freely available to the scientific community. OrangFACS increases potential for the study of communication, emotion and inter-species comparisons.