"It's his worst format," Wade said. "It was not as pronounced as McCain wandering around. Obama in a town hall is more long-winded. He just can't help himself."

Both candidates tend to fare well in settings in which they are standing behind podiums.

"The setup with lecterns and longer questions and answers allows for more direct exchange," Wade said. "They're looking at the moderator and the audience, but they're also able to look at each other."

But there's also a psychological disadvantage to this, said SIU's Graham.

"When seated, the candidates become less aggressive," he said.

For viewers, that's a good thing, Graham added, saying that voters tend to see aggressive debating tactics as bullying.

"For God sakes, don't actually debate. If you actually debate you tend not to do well in the polling the next day," he said. "The public tends to think they were too aggressive and mean and they don't like them."

Even things like height differences alter perception and the types of gestures a candidate should use, Wade said.

"Most of the presidential primary debates were the standard format of the line of humans behind lecterns. It generates some power dynamics in size difference," she added. "We associate height with power. It's a subtle stereotype that goes on."

So someone smaller, like Rep. Michele Bachmann of Minnesota, "had to use larger hand gestures to compensate with size," Wade said.

At 6-foot-1 and 6-foot-2 respectively, Obama and Romney are on an even footing.