Left-Right confusion
For about 85% of people, left and right is as obvious as up and down. As for the rest of us, we have to consult our hands, either by looking at them, or imagining them.
If you’re curious about how good you are at distinguishing left from right compared to other people, take this online test.
What explains this difference?
Most people have strongly lateralized brains, with a dominant left hemisphere that results in a strongly dominant right hand. Somehow, this gives people a stronger sense of left and right in their own bodies. People with L-R confusion have brains that are more symmetrical than normal. Our two body and brain halves are more similar, so they are easier to confuse.
This theory is further supported by the fact that animals with highly symmetrical brains (which includes pretty much all nonhuman animals, including pigeons, rats and octopuses) are very poor at telling right from left.
What parts of the brain are involved in left-right discrimination?
The angular gyrus. (Orange in the above illustration.)
What else are we bad at?
You’ll be unsurprised to hear that people with L-R confusion also tend to have dyslexia and topographical agnosia — neurology speak for getting lost all the time.
Do we get any advantages?
Yes! People with L-R confusion are better at symmetry detection than our highly lateralized peers. We are faster to distinguish whether two images are a mirror image of one another (or an asymmetrical repetition) by about a tenth of a second. I have no idea how this might come in handy in everyday life, but I am doing my best to lord it over my lateralized husband.
