Inattentional Blindness

A friend waits for you at a café, reading an email on their phone. When you arrive on time and sit down across from them, they don’t seem to notice. A minute later, they look up and jump: “Whoa, when did you get here?” You laugh and remind them you already said hello and asked how their day’s going, but they genuinely didn’t register your arrival. Their attention was so locked into the email that their brain filtered out everything else—even you.

Missing something right in front of us is a common mental shortcut to preserve our brain's capacity to focus on something it deems more important. The brain, working to stay efficient, filters out what it doesn’t expect or isn’t actively monitoring. Even with you sitting directly across from them, your friend’s attention was elsewhere, so their brain didn’t fully register what was happening around them.

Unlike change blindness, which involves missing something because it’s different from what we expect, inattentional blindness doesn’t require anything to change—we just don’t register what’s there. If you're watching a cooking show and the color of the cutting board changes between shots without you noticing, that’s change blindness. If you're so focused on the recipe that you don’t even see the cat walking across the counter in the background, that’s inattentional blindness.

Inattentional blindness can happen in classrooms, meetings, crowded sidewalks, or critical roles like emergency response and law enforcement. When attention narrows, so does perception, making it easy for relevant details to go unnoticed simply because the brain wasn’t tuned in. Without our attention, it might as well not exist.