Earlier this month, The Where, the Why, and the How, that wonderful illustrated compendium of scientific mysteries, shed light on the science of why we blush. Just a couple of days later, the creative duo behind AsapSCIENCE — who have previously illuminated such enigmas as the science of lucid dreaming, how music enchants the brain, the neurobiology of orgasms, and the science of procrastination — brought their signature style of sketchnote science storytelling to the same question. Blushing, in fact, has perplexed scientists since Charles Darwin, who famously studied human emotional expressions and called blushing “the most peculiar and most human of all expressions,” and theories as to its exact evolutionary purpose remain unreconciled.

For more on the science behind the body’s peculiar involuntary conducts, see Curious Behavior: Yawning, Laughing, Hiccupping, and Beyond.