The Idiot Brain

Who needs predators when we have our expanded craniums to drag us down with persistent stress?

our brain is primed to think up potential threats.

Facial expressions mean other people can tell what someone is thinking or feeling.

human brains are controlling their own development!

Placing a prisoner in solitary confinement for too long is considered a form of psychological torture,1 demonstrating that human contact is more a necessity than a desire.

Things that don’t conform to our mental model of how the world works are often downplayed or suppressed; they don’t conform to our expectations or predictions, and the best explanation is that they’re wrong, so can be ignored.

Depression invokes inexplicable low mood, so any experiences that are even slightly negative (perhaps someone leaving a table just as you sit down next to them) become significant and are interpreted as people intense disliking you due to your awfulness, and thus delusions occur.

The delusions themselves can in fact suggest the nature of the problem producing them.32 For example, excessive anxiety and paranoia would mean an individual is experiencing unexplained activation of the threat-detection and other defensive systems, so it would try to reconcile this by finding a source for the mysterious threat, and thus interpret harmless behaviour (for instance someone muttering to herself in a shop as you pass) as suspicious and threatening, provoking delusions of mysterious plots against them.

This is the basic process believed to underlie delusions in general; the brain expects something to happen, it perceives something different happening, the expectations and occurrence don’t match, a solution to this mismatch must be found. It starts to become problematic if solutions rely on ridiculous or unlikely conclusions.

The brain has to deal with a lot of information at every given moment, and to do this effectively it maintains a mental model of how the world is meant to work. Beliefs, experiences, expectations, assumptions, calculations – all of these are combined into a constantly updated general understanding of how things happen, so we know what to expect and how to react without having to figure it out again each time. As a result, we’re not constantly surprised by the world around us.