From PhysOrg:
A study conducted to learn more about mimicry of facial features has found that people tend to mimic smiles directed at them by other people based on their own feelings of status and power. The team, led by Evan Carr of the University of California presented its findings at this year's Society for Neuroscience conference in New Orleans.
…In analyzing the results, the researchers found that those people who were feeling more powerful tended to smile in response to smiles on the faces of people that were deemed less powerful or lower in status, but didn't smile back when smiled at by someone that was deemed more powerful. Those that were feeling less powerful on the other hand tended to smile back at anyone that smiled at them. Carr suggested in his presentation that the results of the study show that people smile back at those that they feel are less powerful than them as a means of displaying their own status. And when they are feeling powerful, they hold back on smiling at others perceived as more powerful to avoid showing deference. When people are feeling low power they smile back at everyone as a sign of submission. The researchers also found that people tend to frown back when someone they view as having more power frowns at them no matter how powerful they themselves are feeling.
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