Previous studies with Westerners have found that both the mouth and eyes are crucial in identifying and interpreting smiles. We proposed that Easterners (e.g., Chinese and Japanese) evaluate the role of the mouth and eyes in smiles differently from Westerners. Individuals in collectivistic Eastern society heavily rely on information from the eyes to identify and interpret the meaning of smiles.

We designed an experiment to test the application of optimality theory (OT) in kinship terminology studies. Specifically, we examined the OT constraints within a set of behavioral data using Chinese kin terms. The results from this behavioral approach support and extend Jones' linguistic approach by identifying underlying cognitive mechanisms that can explain and predict behavioral responses in kinship identification.