‘‘Keep your limbs away from your body,’’ says Deborah H Gruenfeld, a social psychologist who teaches at Stanford University. Some research shows that people posed in expansive postures feel more powerful, exhibit higher testosterone levels and have lower levels of the stress hormone cortisol — all characteristics of high-ranking social status. Make eye contact while you’re talking, but feel free to look away when others do. This is what scientists call having a high ‘‘look-speak to look-listen ratio,’’ which is common for dominant members of groups.

Gruenfeld spent decades studying the psychology of power, but she found that her students were flummoxed. They understood the research but couldn’t figure out how to be more authoritative in their own lives. ‘‘It occurred to me that this is what actors do all the time: They show up in character and convincingly act like people they are not,’’ she says. So in 2008, she and a theater instructor began offering a class at the Stanford business school called Acting With Power. To her surprise, the class did not appeal to just women and international students. Olympic athletes also showed up, as well as ‘‘overprivileged, overeducated white guys and pretty much everyone else,’’ she says.

Don’t bother overexplaining yourself. Speak succinctly. Take ownership of the space around you, whether it’s a boardroom or a cubicle. ‘‘Say to yourself: ‘This is my room. This is my table. This is my audience,’ ’’ Gruenfeld says. Most people, women especially, tend to underestimate their standing and worry about being pushy and bossy long before others perceive that to be the case.

You can achieve influence over others by being intimidating and aggressive, but Gruenfeld encourages her students to consider the duties that come with power. ‘‘Think of yourself as a protector,’’ she tells them. This is especially true for women working in male-dominated environments like Silicon Valley. ‘‘I have in mind the queen,’’ Gruenfeld says. ‘‘She has dignity and respect, and she makes people feel safe, but underneath her cape is a sword.’’