Mitt Romney has a “big man” evolutionary advantage over his otherRepublican competitors – and maybe even President Obama — in a hypothetical presidential race, according to a study conducted at Texas Tech University.

The former Massachusetts governor leads the pack of candidates in height at 6-foot, 2-inches tall. Texas Gov. Rick Perry is only 6-feet-1, the same as Obama.

“I would put my money on the taller candidate,” said study co-authorGregg R. Murray, assistant professor of political science at Texas Tech.

According to caveman politics, voters prefer taller candidates. Not only that, but because of their height, tall men see themselves as powerful and are compelled to take a leadership role.

Researchers say it’s a psychological trait that is independent of any cultural conditioning.

The two-pronged study, led by Murray and J. David Schmitz, was published today in Social Science Quarterly and suggests that leadership is hardwired in humans, mostly as a survival mechanism.

“Think about the debates when there is a candidate up there standing on a box,” said Murray. “Clearly, they are sensitive to this stuff.”

The researchers carried out two studies with 467 students from public and private colleges in the United States. They looked at leadership in two ways, from the leader’s perspective and from that of the follower.

The first group was asked to do three drawings: their “ideal leader,” one “typical citizen” and a leader meeting a citizen. Researchers analyzed the third drawing, comparing the height of the citizen and the leader, revealing 64 percent drew a taller leader.

In the second study, students answered questions about their own leadership potential. Those who were taller had more confidence and said they were more likely to run for public office.

“People of greater physical stature emerge as candidates and we see why,” he said. “They feel they are more effective and more capable of running and more likely to put themselves forward.”

Murray is average height and one of his graduate students is 6-foot 7-inches tall.

“He notices how people congregate to him and how he is able to engage socially with other people,” said Murray. “In talking to tall students…they are aware of using their physical stature to sway the conversation toward their perspective.”

Murray and Schmitz looked at the data in the context of tribal behavior in earlier societies, like the ancient Mayans or pre-classical Greeks. They also studied leadership behavior in the animal world, concluding that there is an evolutionary basis in the preference for taller candidates.

“When non-human animals fight, there is a tendency for the bigger of the two animals to win,” said Murray. “In evolution, people in groups were more likely to survive. People in groups with larger leaders were more likely to be the top survivors.”

Even just the perception of stature and size matters among animals.

“If two groups are competing for the same resources and one group is bigger or has a bigger leader, they don’t have to fight it out,” he said. “You could look and see one guy is bigger and probably win.”

“Maybe we as a species have this vestige of a preference for people of greater stature,” he said.

Murray said his findings applied to all humans, not just Americans.

“When we did the study we were fortunate that at Texas Tech there are a lot of international students. What we found were the same effects,” he said.

The study might also explain why a woman has never been a U.S. president, according to Murray. Because females are on average, four inches shorter than males, perhaps “that’s why we have trouble making inroads with women” in politics, he said.

Russell Riley, a presidential scholar at University of Virginia’s Miller Center, said political experts have long known that stature, as well as a host of other physical qualities subconsciously influence voters.

Riley said the height study makes sense in the modern age, but not before voters could actually see the candidates together.

“The vast majority in history had no way of knowing [a candidate's height],” he said. “For the first hundred years or so, you might not even know what a candidate looked like.

Abraham Lincoln was the tallest president at 6-foot, four-inches, but Riley said he would never have been elected today when the visual counts.

“He was ugly,” said Riley of Lincoln. “His political opponents made a great deal about that. He was swarthy and skinny and almost ape-like.”

Beyond height, a candidate’s overall looks also play into politics, according to Riley.

“In the television age — the last half century or so — Americans were considered intelligent if they had a good head of hair,” he said. “When was the last time when we had a president with a follicular deficiency?”

Ronald Reagan was renowned for his cowboy good-looks and his “enormous head of hair” that never seemed to gray, according to Riley. “His large head and broad shoulders gave this almost muscular appearance on TV.”

Riley admits the study has validity “when all other things are equal,” but he was hesitant to use the caveman rule to speculate on who might be the Republican nominee.

“Romney looks like a president,” he said. “He is handsome, telegenic with good hair. He looks like someone right out of central casting.”

But, he adds, so does Rick Perry.

“The two candidates look like mirror images of each other, one gesturing on the left with the right hand, and the other one on the right with the left arm,” he observed of a recent GOP debate. “Both were in dark suits, white shirts and red ties. These folks look like a president.”

By SUSAN DONALDSON JAMES, ABC