Here. Stand on this platform.

Yes, it’s one of those Wii game stands. It is pressure sensitive. Look up at the screen on the wall. You see that circle and that moving crosshair?

You need to keep a steady, even posture for this task, so keep the crosshair in the circle on the screen. That means you are standing even on the board. Okay?
Now. Keep looking at the screen and you’ll see a box open just above the circle and the crosshairs and that box will contain a question. The question will ask you to say aloud what you think is the correct quantitative estimate. Let’s work some examples.
What’s the height of the Eiffel Tower?
How many cups of coffee does the average person drink a day?
What’s the average weight of an adult female koala bear?
Just give your answer aloud and again make sure you keep you posture stable and even by keeping the crosshair in the circle. Let’s begin, How many World Series titles . . .
Can you picture the scene? Research participants are standing on this platform, answering questions about everyday items while maintaining a stable, balanced posture. Each person answers 30 or 40 questions like the examples that all require a quantitative estimate of size, weight, cost, and on and on.
Now. Here’s the trick or the independent variable for this experiment. They put that Wii balance board into one of three positions: Neutral, Left, or Right. In the Neutral position, the board was tried and true, exactly level while in the biased positions, Left or Right, the board was leaning 2% off center. Such a small shift in level is undetectable for most people, especially given all the noise in the situation. None of the participants in any experiments reported any awareness of this imbalance. The circle and crosshairs ensured that everyone stayed in their assigned position, Neutral, Left, or Right throughout the question and answer period.
Obviously since we’re even considering this experiment in the first place, Something Happened and people reported different quantitative estimates of the same items. But in what way? Take a moment and mull over this Embodiment Effect and hypothesize about how body orientation might affect quantitative perception.
Here’s what the researchers found and replicated. People on the Left leaning Wii board underestimated the items while Neutral and Right leaning participants overestimated the items. Consider the key analysis paragraph and a figure to illustrate.
We found a significant main effect of posture, F(2, 64) = 3.38, p < .05, η2 = .10. As predicted, within-subjects contrast analyses showed that participants gave smaller estimates while leaning to the left than they did while leaning to the right, F(1, 32) = 4.42, p < .05, η2 = .12. They also gave smaller estimates while leaning to the left than they did while standing upright, F(1, 32) = 6.45, p < .05, η2 = .17. However, the magnitudes of estimates made while participants were standing upright and while participants were leaning to the right did not differ (F < 1; see Fig. 1).

Those eta2 (η2) effect sizes translate into Medium plus Windowpanes, about 30/70. Left leaners were obviously and practically different from both Neutral or Right leaners who, in turn, were not different from each other. And, again note this effect was replicated in a second experiment.
Lean to the Left see Less. Lean to the Right see More.
The researchers assert this effect occurs because of how humans learned the Number Line. See it.

We associate smaller quantity to the left and larger to the right. We therefore Embody cognition in the form of math and estimation. When we lean Left, we lean to the smaller side of the Number line and when stand Neutral or lean Right, we feel the larger side of the number line.
Of course, the researchers did not offer alternative explanations nor did they test any, so we can consider this some evidence in favor of the Number Line hypothesis, but I’d feel better with testing rival concepts. Maybe there’s something more physiological about balance and visual perception. Maybe there’s a learned political association. Maybe it’s tied into handedness and a biological effect. At the very least we do have replicated experimental evidence of this Embodied Lean effect. Exactly why it occurs is still debatable.
Let’s assume that it is exactly true and natural. This is how all people have always operated, it is just our human nature. Persuasion mavens, let’s make this a Play!
First, how do you produce the Lean Left? Realize this effect occurs without the Other Guys’ awareness so you need a situation that is busy or novel or both. The Other Guys are in the mess of life and thus unaware of their posture. Next, realize the effect occurs at extremely minor amounts of imbalance or leaning. You could rig a chair or stool with the slightest left lean to create the effect. It might also occur when people slouch or rest slightly off center. It might also occur when the Other Guys’ visual field is left leaning slightly. Mavens have many possibilities for producing the Lean Left, some with evidence, others as plausible inferences.
Second, in what situations do you run this? When you want the Other Guys to discount flaws, harms, limitations, in other words, Weak Arguments or Negative Cues, make sure the Other Guys are leaning Left. They will tend to then see the Weaker as the Stronger, thus minimizing the persuasion damage that Weak Args and Negative Cues can produce. Now, of course, shift this when you’ve got Strong Args and Positive Cues. Make sure the Other Guys Lean Right. The evidence in this report suggests the Leaning Effect works best when the Args or Cues revolve around quantitative estimates (less or more) rather than evaluative estimates (worse or better). Thus if the Args or Cues involve numbers, manipulate the Lean. And, I’d argue that you could still probably address evaluative estimates, that worse or better. In this instance the quantitative estimates are better understood as evaluative, attitudinal judgments rather than simple perceptions of reality.
I’m attacking the Embodied Leaning Effect as an Elaboration Moderator or WATTage switch that affects how people think, most particularly the direction of that thinking. Embodied Leaning is a Biasing treatment that shifts the direction rather than the amount of that Long Conversation in the Head.
Furthermore, the Windowpane here is large enough, that this Play could work in a wide variety of practical situations on a regular basis. It’s not one of those 10% differences that requires you to apply the Play with the ardor and commitment of a religious zealot just to get a Small Effect that still demands careful counting to realize the effect. The Leaning Effect is almost Large at 30/70.
Consider limitations. I don’t think this effect would work in High WATT Objective or high value situations. Guessing how many Oscars the movie Slumdog Millionaire received is simply a silly task in everyday life. Sure, you can win a bar bet with it and if that’s your Local as a persuasion maven, go for it. If you are seeking hard behavior change under conflicted circumstances, you might get a brief burst of immediate, favorable change with this effect, but not the enduring change you want. This Leaning Effect is probably best aimed at quick hitters, where you can run the Play on Other Guys, then get an immediate behavior response from Them, a purchase, a name on a petition, grabbing this package rather than that package.
Quickly back to Future Research. I’ve got two thoughts. I’d really like to know if you can produce this with just the participants unaware body orientation OR with manipulating the visual field. First, I could use nonverbal matching where I mirror the nonverbals of the Other Guy. When we sync up, I then make a nonverbal move that Other Guy unconsciously mirrors and put them in the Left Lean or Right Lean as I desire, then make the offer. Second, the Leaning Effect was manipulated with the Other Guys actual posture. Could you instead manipulate the visual field and make things Lean Left or Right and obtain the same outcomes? These would provide useful extensions to both the theory and practice of the Embodied Leaning effect.
The researchers argue that the Embodied Leaning effect flows out of the Kahneman and Tversky cognitive heuristic framework. While the outcomes are consistent with this, a full Monte ELM design that manipulates WATTage across High WATT Objective and Biased, and Low WATT Cue conditions along with manipulations of Argument Quality would be helpful. The Kahneman and Tversky framework confounds WATTage with the operation of System 1 and 2 (roughly corresponding to Routes) which I find a theoretic and practical weakness, an attribute the Nobel committee ignored, dismissed, or overlooked. Maybe I’m not as smart as I think. You are warned!
But, since I rigged your posture while reading this post to Lean Left, you don’t find my stupidity that troubling. Heh-heh-heh.
Sometimes persuasion is that easy.
Eerland A, Guadalupe TM, Zwaan RA. Leaning to the left makes the eiffel tower seem smaller: posture-modulated estimation. Psychol Sci. 2011 Dec 1;22(12):1511-4. Epub 2011 Nov 28.
doi: 10.1177/0956797611420731