Over the past few decades, research in the fields of perception and psychophysics has seemingly demonstrated that our vision is inherently tied to the current psychological, emotional, or physical state of our body. Wearing a heavy backpack makes hills appear steeper (Bhalla & Proffitt, 1999); holding a baton makes objects appear closer (Witt, Proffitt, & Epstein, 2005); holding your arms out to the side makes doorways appear narrower (Stefanucci & Geuss, 2009). Findings like these suggest that the image we see is the product of our brain coordinating information about our visual environment with information about our bodily state. Subtle changes in, say, our body’s position, produce noticeable changes in how we perceive our environment, or so the theory goes.
Several scientists have argued that having distorted vision allows you to better adapt to your environment. Walking up a hill with a heavy backpack requires burning more calories, so seeing the hill as steeper allows your body to anticipate the extra burden. Holding a baton makes a nearby object easier to reach. Holding your arms out makes some doorways impassable.
There are many results like these, and when added together they build a bold, intriguing theory about how we see and interact with our visual environment. However, a growing body of research has raised substantial doubts about this theory, as well as the experimental validity of the evidence supporting it. An article in July’s Perspectives on Psychological Science, called How “Paternalistic” Is Spatial Perception? Why Wearing a Heavy Backpack Doesn’t—and Couldn’t—Make Hills Look Steeper (Firestone, 2013), offers a new perspective in this debate and argues why a theory like this, as intriguing as it may be, cannot actually be true.