The Reward Value of Emotional Genuineness in Williams Syndrome

Typical developing (TD) individuals are sensitive to the authenticity of emotional signals: capable of detecting subtle differences in facial expressions associated with being ‘genuine’ vs ‘posed’. It is not known whether this sensitivity is present in another group of atypically developing individuals that experience social difficulties, i.e. individuals with Williams syndrome (WS). This group is reported to show heightened social drive, speculatively linked to observed atypicalities in face processing. We used an economic key-pressing paradigm to measure the reward-values associated with viewing faces expressing genuine or posed emotions (anger, happiness, sadness) in 16 adults with WS, 103 TD adults (similar in chronological age) and 129 TD children (6-13years, similar range of cognitive ability). Results revealed elevated rewards for happy faces relative to angry and sad faces across all groups. TD children did not differentiate authenticity in their responses, TD adults showed a preference for genuine expressions across emotions, WS participants showed a selective preference for posed happy expressions. Subsequent emotion recognition checks revealed that WS participants experienced difficulties identifying/labelling sadness and anger. Like typical participants, individuals with WS find positive emotions more rewarding, and perhaps surprisingly, where they are sensitive to authenticity, they prefer posed (i.e., social) over genuine smiles.