The importance of posed facial expression production and presentation method on authenticity discrimination

People‘s ability to classify emotional facial expressions is very good, however, their ability to determine their authenticity is much poorer. Generally, emotion recognition research investigates differences in authenticity discrimination by contrasting people‘s perceptions to 'posed‘ and 'genuine‘ expressions. However, such a broad categorization is inadequate for accurately capturing decoder perceptions. We argue that the technique used to produce posed expressions significantly affects how decoders perceive and discriminate authenticity. Second, that decoders perception is affected by seeing these in a dynamic or static format. To demonstrate the importance of production method and presentation format, in a series of studies decoders were assessed on various facial expression types. Senders were filmed as they experienced genuine surprise in response to a jack-in-the-box (Genuine), while other senders faked surprise with no preparation (Improvised) or after having first experienced genuine surprise (Rehearsed). Decoders rated the genuineness and intensity of these expressions, and the confidence of their judgment. It was found that both expression type and presentation format impacted decoder perception and accurate discrimination. Genuine surprise achieved the highest ratings of genuineness, intensity, and judgmental confidence (dynamic only), and was fairly accurately discriminated from posed surprise expressions. Rehearsed expressions were perceived as more genuine (in dynamic presentation), whereas Improvised were seen as more intense (in static presentation). However, both were poorly discriminated as not being genuine. Overall, dynamic stimuli improved authenticity discrimination and perceptual differences between expressions. Our findings demonstrate the importance for research to consider the type of posed expression used and presentation format.