Throughout science, scientists have studied primate facial expression on the basis of emotion. We assume that facial expressions are paired with an emotional internal state which can be understood by others. Facial expressions are mainly studied in terms of their proximate mechanisms instead of their ultimate implications. The proximate mechanisms refer to emotion while the ultimate implications refer to the evolutionary and communicative functions facial expressions possess. In this experiment, researchers are interested in proving that facial expressions can be an indicator of future behavior instead of just an individual’s current emotional state alone and that they may not be reflections of emotion at all. They tested their hypothesis by using Facial Action Coding System. By challenging the emotional interpretation of facial expression, these researchers argue that this will create new paths to explore neurobiology and cognition with connections to the evolution of facial communication in humans and primates.
Bridget M. Waller, Jamie Whitehouse, and Jerome Micheletta conducted the study by using the Facial Action Coding System (FACS) to select four expressions. The FACS studied the changes in primates facial expressions, for example, whether the lip corners retracted. Researchers studied the expressions and tried to define what these expressions represented. After defining the facial expressions, they showed a crested macaque four different videos of one individual approaching another individual with four different facial expressions. The researchers recorded the crested macaque’s reactions to the four different expressions and gave the macaque different outcomes to choose from based on the expression in the video. When the macaque was shown a neutral expression, it chose a conflict outcome because the lack of information seemed to lead to confusing and ambiguous motives. When the macaque was shown bared-teeth, it chose a peaceful outcome. The result shows that there is further research to be done on the processing of facial expression by the observer/receiver.
In conclusion, this experiment demonstrated that facial expressions are intentional actions that are used for communicating intentions or potential actions. There can now be connections made between facial expressions and social interaction. By separating facial expressions and emotions, it opens up potential fields of study for predictive behavior and neurological bases for facial expressions.
References
Waller, B. M., Whitehouse, J., & Micheletta, J. (2017). Rethinking primate facial expression: A predictive framework. Neuroscience And Biobehavioral Reviews, 82, 13–21. https://doi.org/10.1016/j.neubiorev.2016.09.005
Evangeline Grace
October 16, 2018 — 10:19 pm
Very interesting article! The use of facial expressions to convey action intent is one of those things that seem like they should be obvious- but only after you see the study results! I’d love to see a slightly more complex version of this study replicated with humans.
Jasmine Berry
October 16, 2018 — 11:58 pm
I think the results from this study can be applied to humans as well. Often people make judge people by their facial expressions and make act differently towards them if they perceive them as unwelcoming and mean or nice and friendly. Although for humans, there is more nuance, since a person may look mean but may be friendly.