28 Feb 2017

The idiot brain's reptilian origins

From Nine To Noon, 10:06 am on 28 February 2017

Do you ever suspect your brain is sabotaging your life?

Neuroscientist (and sometimes stand-up comedian) Dean Burnett has written a book about the funny ways our brains work.

His book The Idiot Brain explores everything from why the brain needs to sleep, what high IQ really means, why some people like to get scared and why some are susceptible to conspiracy theories.

He's also got some ideas on why US President Donald Trump behaves like... Donald Trump.

Part of that feeling we get that our brain is working against us is because two parts of our brain - the reptile brain and the neocortex - are essentially living in different worlds, Burnett says.

The reptile brain, which is what keeps us alive, has been unchanged for millions of years. It is pre-rational, easily triggered, deeply entrenched and so reactive as to be almost automatic.

The neocortex ("the big wrinkly bit right at the top") is the part that makes us smart. It is where language processing, creativity, rationalisation, imagination, and perception take place and is responsible for the creation of our complicated high-tech human world.

"The neocortex is constructing and navigating our complex society with all our friends and our work and our jobs and our ambitions and dreams and drives and this fundamental part of our brain which is thinking there's a wolf around every corner and this meal might be your last."

Dean Burnett, author of The Idiot Brain

Dean Burnett, author of The Idiot Brain Photo: Supplied

But why has the brain not evolved to be less reptilian (or reactive) in situations that don't require fight or flight?

The reptilian side is so powerful because it requires much simpler processing and gets into gear a lot faster, Burnett says.

"The brain has the habit of taking the easy option because everything else costs it resources."

The thinking brain can override these automatic responses, but it requires a lot of energy and focus, he says.

Some emotions which we may want to discourage in ourselves, like anger, can also be potentially very useful to us, though. While anger diminishes our ability to accurately assess risk, it can help resolve stress.

"Anger ramps up the 'approach' response. When you're more likely to take on the issue, you're more likely to deal with things [rather than avoid them]"

Burnett says our brains tend to create a mental model of how the world works which supports our deeply held beliefs.

"If someone we regard highly is caught up in a scandal, the brain can resolve the cognitive dissonance this causes by either creating an explanation (which leaves our beliefs intact) or incorporating the information into a changed belief, i.e. "I like this person, they appear to be a bad person. I don't like that so I must try and find a way where either I'm wrong or the world is wrong."

The process of accurate self-appraisal (including appraisal of our own intelligence) itself requires intelligence, Burnett says.

Donald Trump's self-perception is a potential example of a psychological condition in which this fails - the Dunning-Kruger effect.

"Intelligent people are able to look at themselves, look at others, have an awareness of what they are capable of and compare and contrast that to what other people are capable of or what they should be capable of and find themselves at a certain level - "I can do this, other people can do that.

"If you don't have sufficient intelligence to be able to assess your own abilities and assess your own intellect effectively then you will be unaware of the fact that you're not as smart as some other people. Therefore you have no reason to believe them over your own conclusions and you start saying things and doing things with utmost confidence because it never occurs to you that you might be wrong."

Modern life provides no shortage of potential threats for the brain to recognise or imagine, Burnett says.

"Whereas a primitive person would think 'I just heard a growl behind me, that's a threat', or 'I see a shadow in the trees, that's a threat' we can think 'Oh, well, I might lose my job if the economy doesn't increase, that's a threat because I won't have money and I won't be able to buy food and I'll starve and I'll die' and 'Someone is coming over, are they a suspicious person, are they someone I should talk to or should I avoid them?' or 'My mother hasn't called me, she usually calls at this hour, something's gone wrong with her'"

"The brain has been fearing things for a very long time and it sees no reason to stop that yet."