It's the cheapest, most low-tech life hack you'll find.

Power posing: the act of taking a posture of confidence, even when you don't feel so confident, to make yourself more dominant.

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Social psychologist Amy Cuddy struck a chord in the business world at TEDGlobal 2012 when she gave a talk about the scientific evidence behind power posing. Her research showed that standing or sitting a certain way triggers immediate changes in your body chemistry.

It can affect the way you do your job and interact with other people. It might even have an effect on your chances of success.

Here's how it works: High-power posing is about opening up, Cuddy says. You stretch and expand your body to take up as much space as possible. It's similar to how primates behave in the wild. They puff out their chests and extend their limbs to make themselves appear — and feel — big.

After assuming a high-power pose for just two minutes, your testosterone levels (the "dominance" hormone) can rocket 20% while your cortisol levels (the "stress" hormone) fall sharply. This allows you to better handle stressful situations.

We decided to test out some of the poses. Some of them have names created by Cuddy; others we came up with. We'll break down which to use in eight common situations that affect your work success. 

FOR SLEEPING: Lie in an open position with your arms and legs outstretched.

Becoming more powerful starts the night before. It's time to nix the fetal position.

Sleeping on your side with your arms and legs pulled toward your torso is considered a low-power position, Cuddy says. You may wake up feeling sensitive and vulnerable without understanding why, which is not a good way to face a chaotic, competitive workplace.

The power position, which we'll call "The Marissa Mayer," makes you feel bigger and, therefore, more powerful. You can also put your hands behind your head (á la Mayer in her Vogue photo spread), which is a power pose that Cuddy often mentions in her talks.

FOR SPEAKING IN A MEETING: Tightly cross your arms across your chest and roll your shoulders back.

Doing "The Mr. Clean" can help drive home an argument in the boardroom.

Your shoulder posture in this position is pivotal in shaping how observers interpret the folded arms, according to Noah Zandan, president of communications-analytics company Quantified Impressions.

If the shoulders are rolled forward, others will interpret the arms as a sign of weakness, sending the message that you're scared. But if you roll those shoulders back and hold your head high, the crossed arms become a signal of confidence.

While you're at it, Cuddy says it's important when you raise your hand to extend your arm fully, taking up space, as opposed to resting the elbow on the table. Women tend to bend at the arm more than men.

FOR CLOSING A DEAL: Plant your hands on the table and lean forward.

As you're rounding the last bend of your presentation and preparing to deliver the bottom-line offer, command the room with a position Cuddy calls "The Loomer." Leaning forward while standing shows you're engaged and in a position of dominance.

Cuddy named this pose in tribute to Lyndon B. Johnson. "Johnson was six-four," and he used his stature very thoughtfully, to intimidate and seduce," she says.

FOR PITCHING AN IDEA: Rest your feet on the table, clasp your hands behind your head, and lean back.

We call this one "The Obama," because the commander in chief can often be seen with his feet propped up on the Oval Office desk.

This is a tough one to pull off, but Cuddy assures us that resting your feet on the desk — preferably your own — and placing your hands behind your head can lead you to take more potentially profitable risks, like saying your next Big Idea out loud.

FOR INTERVIEWING: Plant your feet widely and stretch your arms overhead in a V shape.

Striking a high-power pose in your interviewer's office could come off as offensive, presumptive, and rude, regardless of how it makes you feel, Cuddy says. Here's the alternative, which she calls "The Performer" in honor of Mick Jagger.

Before the interview, throw your hands in the air and widen your stance, as if you're soaking in the applause after an encore performance. Do it in the elevator or stairwell on your way up to the office, or in the bathroom before checking in with reception. Hold the pose for two minutes to set those hormonal changes in motion and give you the confidence you need to ace the interview.

FOR CONDUCTING AN INTERVIEW: Rest your arm on the back of your chair, keep your knees apart, and recline.

"Lean in" by leaning back. It's the perfect way to assert your confidence and comfort level when grilling a job candidate.

This less bro-y rendition of "The Obama" emphasizes opening up the body, while keeping your feet on the ground. Cuddy named it "The CEO" after seeing a photo of Oprah Winfrey looking like a total boss.

Variations include placing your hands behind your head and resting an ankle on the knee.

FOR CHIT-CHAT WITH YOUR BOSS: Puff out your chest, plant your hands on your hips, and stand with feet hip-width apart.

When your boss joins you in line at the K-cup brewing machine, you may feel your heart quicken as your mind scrambles to come up with a more interesting response to "How was your weekend?"

Channel your favorite superheroine and take what Cuddy calls "The Wonder Woman," a classic crime-fighting pose. Tilt your chin up to maximize the power trip.

This position has the opposite effect of touching your neck, which suggests anxiety or lack of control and is considered the lowest power pose of all.

FOR NEGOTIATING A RAISE: Pinch your lower eyelids.

The latest fad in body language is what photographer Peter Hurley calls "The Squinch."

Hurley's video, which has been viewed more than 1 million times, demonstrates how slightly "squinting and pinching" the eyes makes celebrities instantly more photogenic.

"Confidence comes from the eyes," Hurley says. "So does fear." When we make those wide, deer-in-the-headlights eyes, we send a message that we're nervous. But tightening the palpebral ligament — bringing the lower eyelid up — shows your boss you know your worth.  

Try pairing the squinch with one of Cuddy's high-power poses for a killer combo. 

Watch Amy Cuddy's TED Talk here ...

Now see how the professionals do it.

14 Executives Demonstrate The Art Of The 'Power Pose' »

See Also:

8 Power Poses That Will Make You More Confident At Work15 Meaningful Jobs That Pay Really WellExcellent Career Advice From LinkedIn's Billionaire Founder Reid Hoffman