We can’t draw the same simple shapes our brains excel at seeing
Even if you claim you can “barely draw a straight line,” you can recognize one, right? A circle is likely even harder to make, even though you can probably notice when the Moon isn’t quite full yet, or if a tire is looking low. This gap between observation and creation isn’t due to some particular deficiency in your drawing abilities, it’s more of a gap in our species’ evolutionary needs. Recognizing subtle visual cues about the world helped keep us alive, while inscribing flawless geometry… didn’t.
Seeing for survival
While recognizing a perfect circle is much more common than being able to draw one, that doesn’t mean it’s a simple process. We’re good at it because our visual centers have been evolving for millions of years to handle it. Behind the scenes, multiple batches of neurons are working to parse the visual information brought in from your eyes, with some focusing on pattern recognition, some other edge detection and others dwelling on proportions. This sophisticated process came about because subtle details could help us notice a snake hiding in a tree, find untarnished fruit, recognize facial expressions, etc. As a highly visual species, we’ve invested a lot, on an evolutionary scale, to be able to tell when a circle is a bit off.
Drawing is still difficult
Taking a perfect circle out of your brain and putting it on paper is a frustratingly different process. Because drawing flawless, symmetrical geometry hasn’t lent itself to our survival over the ages, our brains and bodies haven’t specialized in it much. Even if your brain knows a circle when it sees one, it has to reverse engineer that shape into a series of commands to your arm, which is already a step in the wrong direction for that kind of geometry. To save effort, our brains will often try to complete a motion from single joint, which leaves us often trying to draw a circle from our shoulder. If you’re sitting at a table, this means that we actually need more energy and calculations to make further adjustments at your elbow, and more at the wrist, and then the fingers. The number of moving parts leaves you drawing by a sort of anatomical committee.
To demonstrate the amount of cognition required to draw, people have been asked to draw a series of much simpler shapes – horizontal lines. Most didn’t have a problem with this, until they were asked to simultaneously do some arithmetic in their heads. At that point, the subtle adjustments to their drawing from their elbows and wrists started to fade, and most participants started making more diagonal strokes, which is what their shoulder really felt more comfortable doing.
Learn to shape your circles
Obviously this isn’t a lost cause, as many humans have drawn and painted some really amazing things. A lot of that may be thanks to practice, since practicing teaches our brains what motions should and should not be part of any action. And while few people crank out mechanically perfect circles, people who draw or paint more often have been found to make better looking circles than people who don’t, even though they were all equally capable of recognizing when a shape was off-kilter. Experience (from Painting I, back in the day) also teaches you to work with your body’s preferences— if you have the space, it’s often easier to paint bold shapes standing up at an easel, so your arm has plenty of freedom at the shoulder, rather than finagling the whole thing from your wrist.
If you’d like a dependable circle on paper, there are some other tricks to try. When holding a pencil, put the tip on your paper, and your pinky or last knuckle on the paper where you want your circle to be centered. Lock that arm down as best you can, and use your other hand to carefully rotate the paper. If you can keep your hand still, you should have a pretty good circle, at least until evolution gets around to selecting for being able to draw geometry a bit better.
My first grader said: When I want a circle, I trace jar lids.
Yep, that works too.