Our brains have a set of built-in shortcuts that influence us every day. Behavioral scientists call these hard-wired limitations heuristics, and researchers have isolated dozens of ways in which heuristics affect us.

One such heuristic is narrow framing, which occurs immediately and inevitably when our brains perceive a nearby danger. This automatic reaction is designed to help us protect ourselves.

For example, last summer I was on a hike and encountered a rattlesnake. On that cool morning, the snake was curled up in a patch of sunlight. My brain, instantly activated, used narrow framing to deal with the snake. All my senses and every bit of my brain’s processing power were focused on that one spot of sunlight. I was no longer aware of my surroundings because my brain zoomed in on the snake and edited everything else out of my awareness.

Millions of years of evolution were packed into that moment, and I avoided what could’ve been a bad experience.

The Problem of Complexity

Narrow framing also gets activated when the brain is faced with too much information. This forces you to automatically ignore any extra data so that your brain can process whatever it decides is important. This is how you can carry on a conversation in a crowded and noisy room.

Importantly, this means you cannot carry on one conversation and pay attention to another. If you try, the brain shifts back and forth from one narrowly framed piece of information to the other. Because of this natural limitation, there is no such thing as dual processing.