At the root of this illusion is an evolutionary trait: humans evolved to quickly detect faces. Our survival often depended on identifying friends or foes — so our brains developed specialized visual mechanisms to recognize faces even under poor conditions. As a consequence, even vague clues — like folds in blankets, shadows, or the outline of long hair — can trigger those face‑recognition circuits and make the brain “fill in” details.

Research supports this. Studies have shown that when we see “illusory” faces in objects, our brains activate the same neural pathways as when we see real human faces. That means the emotion, familiarity, and social cues our minds attribute to those shapes are not just imaginative: they’re rooted in the same neurobiology used to interpret real human interaction.

So when you looked at soft blankets and pillows — with folds, shadows, and shapes — your brain essentially mistook them for a human figure. That split‑second “recognition” of extra limbs or features isn’t random; it’s a byproduct of a brain optimized for detecting living beings quickly and efficiently.