Research shows we trust attractive people more — but we also expect more of them.

Beware of strangers. Don’t judge a book by its cover. We repeat these timeworn adages without even thinking, but new research suggests we live by neither of them. According to this study, attractive strangers are trusted more. But more is expected of them as well, and if they do not live up to the trust placed in them, they may be penalized more heavily than those who are less attractive.

Trust is a key concept in political science, and much research has delved into what makes people trust one another. A recent study looked at the snap judgments people make in deciding whether to trust strangers and whether attractiveness enters into the equation. It shows people are willing to judge a book by its cover, even though from a strategic standpoint, they should not.

“We found that attractive subjects gain a ‘beauty premium’ in that they are trusted at higher rates, but we also found a ‘beauty penalty’ when attractive people do not live up to expectations,” said Rick Wilson, the Herbert S. Autrey Professor of Political Science and professor of psychology and statistics at Rice University. Wilson is co-author, with Catherine Eckel, professor of economics at the University of Texas-Dallas, of a study entitled “Judging a Book by Its Cover: Beauty and Expectations in the Trust Game.”

Several previous studies have shown a considerable level of trust between strangers. The fact is — even though our mothers advised us otherwise — we are not cautious of strangers. And, as far as judging a book by its cover, research shows race has some bearing on trust. But what about the attractive stranger?

“We were interested in whether people infer something about their counterpart based solely on a surface judgment, and whether these judgments are correct,” Wilson said. “To this end, we turned to an easily observable, seemingly noncredible but difficult to mimic, aspect of people: their attractiveness.”

Prior research has shown that people attribute a variety of positive characteristics to attractive people, including intelligence, competence and leadership skills. It appears attractiveness pays in the marketplace, and this has been referred to as a “beauty premium.” Dating at least from the famous televised “dark shadow” debate between Kennedy and Nixon, political scientists have noted a beauty premium for candidates.

Researchers in this study set out to find if people rely on attractiveness as a way to decide whether to trust strangers. If so, do attractive people gain from being trusted?

A total of 206 students from Virginia Tech, Rice University and North Carolina A & T participated in the experiment. A little more than half were males, and 94 percent were between 18 and 22. Researchers took care to recruit an ethnically diverse group.

The researchers used a two-part experiment to examine trust and attractiveness. In the first part, subjects were photographed and took part in a series of “trust games.” In the second part, another group of subjects evaluated the photographs for attractiveness.

Each person in the first group posed for four photographs — two neutral and two smiling — then he or she picked one to be used for the game. Each was given 10 “lab dollars” to exchange during the game. Then they were shown photographs of other students and told to send any amount they wanted to each of them. The experimenter then tripled the amount and gave it to the second student. Then the recipient decided how much to return to the sender. Students kept the money that was exchanged.

In the second part of the experiment, another group of students evaluated the photos for 15 traits, including attractiveness. Researchers controlled for gender, race, facial expression, glasses and jewelry so those factors did not enter into the decision.

In the trust games, on average more money was sent to attractive people. Likewise, trusting attractive people was justified because they tended to reciprocate with higher amounts of money. Apparently, trusting attractive people pays.

However, recipients had higher expectations of attractive people, and if they did not receive as much as they expected, they punished the attractive senders by returning less of the money to them.

“Attractive people were penalized more when expectations were dashed, setting up a ‘beauty penalty,'” Wilson said. “While attractive people sent more money, they received less.”

“These findings suggest we turn a deaf ear to our mothers’ advice not to trust strangers,” Wilson said. “Not only do we trust them, we trust them based on their appearance — so we’re judging books by their covers as well.”

What impact might these findings have on the larger picture of society? In today’s environment of visual media, people often make snap decisions based on brief sightings. This research confirms what has been found in other studies in political science: attractiveness matters when people are evaluating candidates.

“Also, attractive people may be more successful in acquiring social capital because they are trusted in the initial exchange,” Wilson said. “Whether or note they are more productive doesn’t seem to matter — the fact is they get an initial advantage.”

Just why we are so attentive to attractiveness may have roots in centuries past.

“Attentiveness to attractiveness may be embedded as part of our cognitive apparatus,” Wilson said. “There are evolutionary reasons why humans might be attentive to attractiveness, including that historically it signaled good genes, substantial parental investment or status.”

Wilson is involved in a number of research projects that use experimental methods to explore strategic choice. He has designed experiments that explore the development of cooperation in numerous bargaining games. This research has a strong cross-disciplinary cast and is supported by grants from the National Science Foundation and is facilitated by the Rice University Behavioral Research Laboratory.

Wilson is also an expert on the evolution of American political institutions. He is the co-author of “Congressional Dynamics: Structure, Coordination and Choice in the First American Congress, 1774-1789” and has published articles in a wide range of scholarly journals. He is chair of Rice’s Department of Political Science.

For more information at http://www.rice.edu