The Theory of Facial Expressions

In terms of the physiological or biological study of facial expressions, many scientists and researchers agree that ‘Facial expressions involve contractions of single muscles and muscle groups, caused by messages from motor cortex & subcortical regions’. However, in terms of forming a consensus regarding the functions of facial expressions, there has been controversy about the reasons behind facial displays, which include evolutionary and cognitive theories, as well as behaviorist ideas. Two focal theories emerged with the discussion of the functions of facial expressions that have been thoroughly investigated amongst many researchers; the Emotion-Expression view, which claims that function of facial expressions lies in the expression of the internal emotion that lies within a person (Parkinson, 2005). The behavioral ecology view theorizes that facial expressions are voluntary displays that serve communicative functions that arise during face-to-face interaction and are not associated with emotions (Parkinson, 2005).

Many studies and observations have been developed to test this hypothesis, providing evidence and support for the theories presented, this essay will present and discuss the studies developed in order to draw a conclusion on the understanding of the functions of facial expressions in humans. Darwin’s (1872) idea of facial expressions presented the notion that facial displays are evolutionary adaptations, which he expanded with the claim that facial expressions derived from an inner emotional process that would assist organisms in communication as well as protecting and preparing the organism for action (Thibault, 2009).

Darwin introduced three principles in relation to the science or understanding of facial expressions; The first principle “principle of associated serviceable habits” meaning that facial expressions serve as a direct response to a situation that requires an adaptive emotional response (Parkinson, 2005), “The principle of antithesis” which is the understanding that expressions are ‘side effects of previously relevant associations and counter-associations’ (Parkinson, 2005), the third principle is “the principle of action of the nervous of the nervous system” meaning that facial expressions are a result of a physiological trigger stemming from the nervous system when emotional states arise (Parkinson, 2005). This hypothesis introduced the Emotion-Expression view, which holds the claim that there is a universal communicative factor to facial expressions. This introduced the research question on the universality of facial expressions and whether they are interlinked with emotion (Thibault, 2009). Darwin’s claims and principles on facial expressions were not explored until the 1970’s, researchers then began to gather evidence to test the theory that facial expressions are universal and have a direct association with underlying emotion (Thibault, 2009).

Ekman, Sorenson, and Friesan (1969) researched the claim that ‘Emotions are universal, and expressions should be recognized from other cultures’. The researchers displayed pictures of participants expressing six different emotions and instructed those taking part to assign the term which best fit the feeling illustrated in each photo, the results conveyed high accuracy rates. However, critics doubted the validity of the experiment due to those taking part ‘perhaps’recognized the facial media from Western media (Keith Oatley, 2006). Ekman and Friesan (1971) conducted additional research to provide stronger evidence of the emotion-expression understanding of facial expression, the study was conducted amongst those whom had little to no contact with Western culture, again participants were given photographs showing a variety of facial expressions, combined with a story linked to the expressions, and were told to choose the photograph which best fit the story.

The universality hypothesis was confirmed in the results, as the accuracy rates were significantly high. Ekman and Friesan (1971). Sorenson (1976) cast doubt on the study conducted by Ekman and Friesan (1971) with claims that the researchers had influenced the responses due to method artifacts. The materials used in the study were also subjected to criticism as each story presented to the participants was associated to an emotion term, the themes of the stories were also criticised for being based on a Western approach (Mandal, 2015). Despite the many disputes regarding Ekman et al.’s studies on the universality of facial expression and whether they are interlinked with underlying emotion, over 70 studies supported the universality hypothesis, demonstrating that emotions in facial expressions are universally recognized (Matsumoto, 2008).

Many of these studies, however, merited criticism due to the research being carried out in controlled environments and may not have reflected real-life situations (Matsumoto, 2008). To challenge the inaccuracy of laboratory-based research, a study by produced additional compelling evidence for the universality hypothesis by observing spontaneous emotion expression in both victorious and defeated athletes competing in the Olympics; finding that athletes born with a visual impairment harboured the same facial expressions as athletes without this disability, further confirming that expressions do not differ due to culture and are rather innate in organisms (Matsumoto, 2008). Though psychologists have differed in opinion regarding the universality of emotion expression, a consensus relating to “the principle of action of the nervous of the nervous system”, that there is universality in some expressions that are triggered by certain emotions such as fear and surprise which serve survival based skills.

Susskind et al. (2008) found that participants expressing the emotion of fear portrayed specific physiological changes, such as enlarged visual fields and faster eye movements, this relating to Darwin’s theory that facial expressions may serve to the purpose of an organism preparing for action in a threatening environment. Further studies conducted by Anderson (2008) in observing the expression of surprise, found that the physiological changes expressed with the emotion of surprise were similar to the expression of fear. Providing further evidence that facial expressions served for survival and evolutionary functions, was a study conducted by Daniel et al. (2014) observed stimulus that arises with the emotion expression of anger and disgust, finding that stimulus detection increases when eyes are enlarged and the narrowing of eyes during the feeling of disgust results in discrimination, these physiological changes increasing the organisms’ sensitivity or awareness. These findings displayed evidence for the theory of facial expressions being a result of triggers in the nervous system when placed in an environment that requires defense or action.

Though the theory of facial expressions serving the purpose of emotion-expression, academics and researchers have developed other theories relating to the purpose of facial expressions; one prevalent hypothesis being the ‘Behavioural ecology view’. Fridlund (1994) proposed the idea that facial expressions serve the purpose of communication rather than the expression of emotion, also claiming that the content of facial expressions does not derive from underlying emotions but from socially motivated themes, making them voluntary and not entirely spontaneous reactions (Parkinson, 2005). A natural observation conducted by Kraut, Robert E. Johnston, Robert E. (1979) on bowlers who seemed to display facial expressions such as smiling when socially engaged but not necessarily after scoring in the game, another observation at a hockey game showcased similar reaction as fans displayed smiles when engaging in the social setting. These findings supported the hypothesis that facial expressions emerge during socially engaging or interactive context and are voluntary rather than spontaneous.

However, these natural observations were criticised due to their ecological methods as they did not engage with the participants resulting in a limitation as there was no direct test of the subjects' actual emotional experience at the moments in which they were observed (María-Angeles Ruiz-Belda, 2003). Ruiz-Belda et al. conducted a study that observed bowlers playing blowing as well as football fans watching a football game, the participants were required to report on their feelings and then were assessed during both an interactive and non-interactive occasion, noting that the reports on their feelings of happiness remained at the same level regardless of being in an interactive or non-interactive context, the observation noted that participants smiled very little in the absence of social interactions and smiled significantly more during social interaction. These observations suggested that the facial expression of happiness is dependent on the social and interactive setting the person is in, rather than an expression of emotion, which the study proposes that happiness would not have been expressed through the facial expression of smiling if it wasn’t due to the participant's interactions.

Another study exploring the correlation of facial expression with social settings was conducted by Chovil (1991) who proposed the notion of ‘An Integrated Message Model’ with the claim that non-verbal acts such as facial expressions are symbolic messages that contribute to communication and the conveying of messages within face to face interaction. Chovil (1991) proposed that the non-verbal acts of facial expressions are shaped by the social context one is in, this theory was demonstrated in a study that observed the participants’ frequency of motor mimicry displays, which were examined in four communicative situations, participants were required to listen to a tape-recording about a close call event, the social situations differed in terms that the participants listened to the call’s in solitude without the presence of others, and then listened to the call in a interactive face-to-face setting, in support of the notion that expression of emotion through facial display correlates with the presence of others, as results showcased that the frequency of the participants motor mimicry increased with the sociality of the four conditions.

Therefore, supporting the notion that facial expressions serve in the interest of communication within interactive settings. Tcherkassof and Fridja (1997) proposed the idea that through facial expressions may imply underlying emotion, the function of facial expression is not to display a person’s emotional state but reflect ‘the state of action readiness’ of an individual, therefore communicating the intention of their next course of action.