Marquette Magazine recently spotted this tweet by Marquette student Emily Tau: “Dear Twitter world, I am feeling crabby today. I need to smile. What makes YOU smile?

The expert: Dr. Nakia Gordon, assistant professor of psychology, whose research focuses on understanding how emotions impact the way individuals navigate their worlds.

“Smiling, like most facial expressions, communicates to those around us what we are feeling. In fact, individuals with relatively little contact with the industrialized world were able to accurately identify at least four (e.g. happiness, sadness, anger, disgust) facial expressions made by those from other cultures. This begs the question whether emotion expressions are universal. Most researchers assume they are.

“While neuroimaging data (pictures of the brain when it is active) tells us how emotional expressions are perceived, it doesn’t tell us why we smile (as opposed to frown, for example). Charles Darwin suggested that facial expressions indicate the intention of animals — and by extension, humans. It takes a small leap of faith to understand his rationale for smiling. In his explanation, an animal will bare its teeth as a warning to other animals. He suggested humans co-opted this behavior as a greeting.

“It has not been resolved whether expressions are learned or innate, but it does seem that all humans use the same expressions to communicate basic emotions. We also know that we manipulate our expressions to have control over what we communicate. You do not have to be happy to smile, and you can smile and not be happy … at least not initially.

“In fact, ‘turning that frown upside down’ can make you feel happier. Research suggests that our brains receive feedback from our muscles (and other internal organs) to help discern how we feel. For example, placing a pen horizontally between the teeth (creating a smile) caused participants to rate comics as being funnier than when the pen was placed lengthwise in the mouth. Emotions such as pride and shame have also been induced simply through body posture.

“But let us be clear, it is not enough to turn your lips upwards. Smiling with your eyes, known as a Duchenne smile, is more effective at creating a sense of positive mood than a ‘fake smile.’ Moreover, genuinely smiling during distressing tasks (such as talking for five minutes about challenges adjusting to college) resulted in better emotional adjustment at a later point. Thus, smiles do not merely represent and communicate how we feel to others, they also help us experience those feelings more robustly. In some situations, they may even help us regulate how we feel.”