WEDNESDAY, April 11 (HealthDay News) -- Holding a gun makes a man appear bigger and stronger than he actually is, a new study indicates.

Researchers at the University of California, Los Angeles, asked hundreds of people to guess the size and muscularity of four men simply by looking at photos of the men's hands holding a number of easily recognizable objects: a caulking gun, an electric drill, a large saw or a handgun.

The hands of the four men in the photos were the same size and had no distinguishing features, such as tattoos or scars. Even so, the study participants consistently estimated men holding guns to be taller and stronger than men holding the other objects.

"There's nothing about the knowledge that gun powder makes lead bullets fly through the air at damage-causing speeds that should make you think that a gun-bearer is bigger or stronger, yet you do," study author Daniel Fessler, an associate professor of anthropology, said in a university new release.

"Danger really does loom large -- in our minds," he added.

The findings suggest that, like other animals, humans have an unconscious ability to gauge a potential adversary and decide whether they would win or lose a physical confrontation, the researchers said.

"We've isolated a capacity to assess threats in a simple way," study co-author Colin Holbrook, a postdoctoral scholar in anthropology, said in the news release. "Though this capacity is very efficient, it can misguide us."

The study, published Wednesday in the journal PLoS One, is part of a larger project funded by the U.S. Air Force Office of Scientific Research to learn about how people make decisions in potentially violent situations.

The findings could prove useful for law enforcement, prison guards and the military, the researchers said.

More information

The U.S. National Institute of Mental Health has more about threat perception.