Prior to the invention of the silver nitrate-coated mirror in 1835, your reflection in the basin or the polished-metal jug used for your morning ablutions was about as good as it got. These days, we grow up seeing ourselves in all our sharply-defined, reflected glory daily. And yet, what we see is not always what we get.
Knowledge is Power, France is Bacon is a reader-supported publication. To receive new posts and support my work, consider becoming a free or paid subscriber.
The naïve physics of mirrors
Although we frequently interact with this commonplace household object, our intuitive grasp of its physics is rather flawed.
Experiments show that adults routinely overestimate what should be visible in a planar (flat) mirror, and anticipate seeing their image in one before they are in front of it. Standing at an obtuse angle to a mirror, they fully expect to be able to see their reflection at the place where they peer into it.
Such erroneous beliefs about mirror mechanics appear to develop over time, due to our tendency to learn not just from observation but also by generating hypotheses (without testing them). Hence, this error is not evident in children aged between five and eleven as these hypotheses haven’t had time to form. Children younger than five haven’t yet understood that looking paths are a straight line (and thus expect to be able to see out of a curved tube).
However, despite children’s lack of this early error i.e. anticipating seeing their reflection before being directly in front of a mirror, their understanding of mirrors is no more accurate than that of adults. Rather than grasping the importance of viewpoint, it’s simply that children mistakenly believe that a mirror can only reflect a section of the room equal to its width.
Another error we make regarding mirrors is to do with projection size. We believe that were we to outline our image in the mirror it would correspond to the size of our face, rather than half the size as in reality (the light having to traverse double our distance to the mirror in order to reach us).
People’s understanding of mirror reflections in paintings is similarly flawed. The Venus Effect refers to the egocentrism of mistakenly assuming that what the subject of a painting sees in the mirror is the same image we see.
Objects in the mirror are more attractive than they appear
You’ve grown so accustomed to your mirror image — and incidentally, the image captured by your front-facing camera in selfies — that you vastly prefer it.
The reverse is true for images of your nearest and dearest. In fact, you’re likely to rate a pair of glasses they’re modelling less positively if their fashion photo has been laterally inverted. (Though it’s worth mentioning that the image in a mirror isn’t “flipped” horizontally on the x-axis, perceptually speaking, but rather inside out on the z-axis much like a glove turned inside out, as illustrated in this video.)
Why are people afraid of mirrors?
The mirror hall trope where the hero comes face-to-face-to-face—you get the idea—with the villain is a classic for a reason. Clearly, we’re as spooked as we are dazzled and befuddled by mirrors. After all, the mirror is the first virtual world that humankind has ever encountered. If only for a second, a mirror reflection can make us question: what is real?
(As an aside, I once very unexpectedly saw my mirror reflection and was briefly able to perceive myself closer to what a stranger might see, without the “fabric my own eye weaves” to quote Kahlil Gibran. I recommend finagling such a thing if you can.)
Curvy, carnival contortions aside, given a mirror reflection’s fidelity, it seems irrational for us to fear glimpsing some untold terror glinting off its surface. It’s surprising, then, how prevalent mirror jump scares are in horror films. What could account for the trepidation, that niggling feeling that the mirror will reveal to use something wholly unanticipated… and terrifying. Perhaps the strange-faces illusion is the culprit.
The goal of perception is to “understand the meaning and importance of our surroundings” and—I’ve once heard argued—to detect potentially imperilling or advantageous changes to said environment. Therefore, if you focus on an unchanging stimulus, say, something as unremarkable as the still reflection of your face in the mirror—your brain will try to interpret it in many different ways in its desperate quest to impose meaning.
Under conditions of low illumination, gazing at your face in the mirror for several uninterrupted minutes results in the strange-faces illusion. The strange-faces illusion is facilitated, as are many misperceptions, by perceptual ambiguity, in this case owing to dim lighting. People brave enough to face their mirror in the gloaming, report seeing “huge distortions of their own faces, monstrous beings, prototypical faces, faces of relatives and deceased, and faces of animals”. In the Jungian view, this hallucination offers us insight into our subconscious projections.
(When I tried this, I was subjected to a version of my face with a constantly roving right eye. Just kidding, I don’t have a mirror reflection!)
Individuals with schizophrenia have the irrepressible feeling that such faces — they sometimes see multiples — are real. This is to be expected as individuals with schizophrenia characteristically mistake self-generated percepts for the sights and sounds of the external world in what’s known as a source-monitoring deficit. Curiously, people with schizophrenia report “feelings of strangeness” when observing their faces in the mirror in general.
In contrast, people with depression either do not experience the strange-faces illusion or else perceive only very faint changes to their reflection in the half-light. It’s theorised that this might have something to do with abnormalities in gaze fixation duration among those with depression. Dwelling just as long on sad faces as happy ones instead of exhibiting a bias toward the positive things in life and, by dint of oft co-morbid social anxiety disorder, submissive gaze avoidance are two examples of this atypicality.
Speaking of recognising oneself in the mirror, that’s in Part II. Part III focuses on mirrors as therapeutic tools. Subscribe so you don’t miss out. I wanted to kick off with a New Year’s reflection on the (apocryphal?) Chinese curse “May you live in interesting times” but that’ll have to wait…in time for the Lunar Year?
Also, thank you very much to my first paid subscriber for supporting Knowledge is Power, France is Bacon.