Witnessed inclusion improves identification of Duchenne and non-Duchenne smiles.

Social exclusion threatens a person's need to belong and prompts them to behave in ways that often facilitate reaffiliation. For adults, direct exclusion increases attention to social information and facial cues, including an enhanced identification of Duchenne and non-Duchenne smiles. Furthermore, inclusion can buffer or mitigate the effects of exclusion. This study investigated children's (N = 44) and adults' (N = 52) sensitivity to perceptual changes in smiles following witnessed inclusion and exclusion and inclusion's mitigating and buffering effects on perceptual abilities. Contrary to our predictions, participants in our study demonstrated improved accuracy after witnessing inclusion, rather than exclusion, and showed no buffering or mitigating effects of inclusion. This contradiction with previous findings points to a further need to explore the effects of witnessed versus direct inclusion and exclusion, especially if witnessed inclusion and exclusion have the ability to impact perception and shape our behavior.