Men with shaved heads are perceived to be more masculine, dominant and, in some cases, to have greater leadership potential than those with longer locks or with thinning hair, according to a recent study out of the University of Pennsylvania's Wharton School.

That may explain why the power-buzz look has caught on among business leaders in recent years. Venture capitalist and Netscape founder Marc Andreessen, 41 years old, DreamWorks Animation SKG Chief Executive Jeffrey Katzenberg, 61, and Amazon.com Inc. CEO Jeffrey Bezos, 48, all sport some variant of the close-cropped look.

Some executives say the style makes them appear younger or at least, makes their age less evident and gives them more confidence than a comb-over or monk-like pate.

"I'm not saying that shaving your head makes you successful, but it starts the conversation that you've done something active," says tech entrepreneur and writer Seth Godin, 52, who has embraced the bare look for two decades. "These are people who decide to own what they have, as opposed to trying to pretend to be something else."

Wharton management lecturer Albert Mannes conducted three experiments to test peoples' perceptions of men with shaved heads. In one of the experiments, he showed 344 subjects photos of the same men in two versions: one showing the man with hair and the other showing him with his hair digitally removed, so his head appears shaved.

In all three tests, the subjects reported finding the men with shaved heads as more dominant than their hirsute counterparts. In one test, men with shorn heads were even perceived as an inch taller and about 13% stronger than those with fuller manes. The paper, "Shorn Scalps and Perceptions of Male Dominance," was published online, and will be included in a coming issue of journal Social Psychological and Personality Science.

The study found that men with thinning hair were viewed as the least attractive and powerful of the bunch, a finding that tracks with other studies showing that people perceive men with typical male-pattern baldness which affects roughly 35 million Americans as older and less attractive. For those men, the solution could be as cheap and simple as a shave.

According to Wharton's Dr. Mannes who says he was inspired to conduct the research after noticing that people treated him more deferentially when he shaved off his own thinning hair head shavers may seem powerful because the look is associated with hypermasculine images, such as the military, professional athletes and Hollywood action heroes like Bruce Willis. (Male-pattern baldness, by contrast, conjures images of "Seinfeld" character George Costanza.)

New York image consultant Julie Rath advises her clients to get closely cropped when they start thinning up top. "There's something really strong, powerful and confident about laying it all bare," she says, describing the thinning or combed-over look as "kind of shlumpy."

The look is catching on. A 2010 study from razor maker Gillette, a unit of Procter & Gamble Co., found that 13% of respondents said they shaved their heads, citing reasons as varied as fashion, sports and already thinning hair, according to a company spokesman. HeadBlade Inc., which sells head-shaving accessories, says revenues have grown 30% a year in the past decade.

Shaving his head gave 60-year-old Stephen Carley, CEO of restaurant chain Red Robin Gourmet Burgers Inc., a confidence boost when he was working among 20-somethings at tech start-ups in the 1990s. With his thinning hair shorn, "I didn't feel like the grandfather in the office anymore." He adds that the look gave him "the impression that it was much harder to figure out how old I was."

Not everyone needs a buzz. Rick Devine, 55, the CEO of Devine Capital Partners, a Redwood City, Calif., executive-recruitment firm that specializes in the tech industry, advises executive candidates tempted by their clippers to keep their hair closely cropped, rather than completely shaved. "It is way too much image risk," he says. "The best thing you can do in a business meeting is to make your look not an issue."

The cue-ball style can strike some as menacing, so Mr. Carley makes an extra effort to appear friendly and accessible when meeting people for the first time or "at least as nonthreatening as a 6-foot-1-inch bald guy can be," he says.

Some consolation for male-pattern-baldness sufferers: Looking older can be helpful in the workplace. Just as older silverback gorillas are "typically the powerful actors in their social groups" in the wild, so it goes in the office, where a bald head may "signal who is in charge and potentially dangerous," says Caroline Keating, a Colgate University social psychologist who studies dominance.

Other physical features that signal dominance include narrow eyes and lips, as well as broad faces and square jaws. For women, the equation is trickier. Dominant features may be less helpful at work than youthful, feminine features, which are deemed more attractive, Ms. Keating says.

A bare scalp "is nature's way of telling the rest of the world that you are a survivor," adds Michael Cunningham, a professor at the University of Louisville, who has studied social perceptions of baldness. He adds that the deliberate shaved-head look conveys aggressiveness, competitiveness and shows "willingness to stand against social norms."

Bald quickly became a big part of Mr. Godin's brand. The entrepreneur says his pate helps him stand out at conferences and meetings. Now chief executive of the website Squidoo, he continues to use the image of his bald head as a design element on his book jackets and personal websites. Shaving off his hair, he says, "turned out be a highly leveraged marketing choice."

Michael Landau, 41, took the plunge once he began losing hair in his late teens. Balding at a young age made him shy and uncomfortable, but shaving off the remaining strands nudged him out of his shell. It even helped lead to a job with Mr. Godin years ago, when the two men bonded over their baldness.

Mr. Landau, now CEO of Drybar, a chain of blow-dry salons, says the bald look "makes me more confident and more strong, which probably makes people respect me more." Plus, in the hair business, he says, "people remember the bald guy."