US President Barack Obama smiles during a town hall style meeting in Atkinson, Illinois. (Jim Watson/AFP/Getty Images)

White Americans are more likely to see anger in the facial expressions of President Obama than non-white Americans are, according to a study from the University of Arkansas that will be published in the journal Political Psychology in July.

The study showed more than 100 participants – who identified as white, black, native American and Asian – a silent video of Obama's 2010 White House Correspondents Dinner speech, a night in which the president traditionally cracks jokes at the press and lawmakers, and asked them to describe how they thought Obama was feeling based on his facial expressions. White participants were slightly more likely to assign anger to the president, rating both his smiles and neutral displays as seven points higher on average than non-white participants out of a potential 100 points.

University of Arkansas assistant professor Patrick Stewart, who co-authored the study, tells Whispers that the findings weren't surprising to him.

"One of the things that literature out there suggests is we are much better at decoding people within our own ethnicity and their facial displays," he says. "I wouldn't use a term like racism because all groups are 'ingroup focused,'" meaning they favor the social group with which they identify.

The study also suggests long-standing stereotypes may have been responsible for the different responses.

"That race still plays a role ... is testament to the lingering power of stereotypes that likely rely upon subconscious triggers such as skin color and facial features," Stewart writes in the study.

Despite different races assigning different emotions to the president, the study also found that Obama was very effective at controlling his facial expressions. While Obama relaxed into "felt smiles" during much of his correspondent's dinner speech, Stewart notes that he used a "controlled" smile when he wanted to, such as while making a joke about Joe Biden that employed the F-word (about 1:30 into the video above).

"You don't want to be too happy when you transgress a social boundary, like dropping a swear word," says Stewart. "So he smiles to signal it's all fun but controls it because he can't enjoy it too much."