The Idiot Brain - Book Summary

by Dean Burnett

“This is a wonderful introduction to neuroscience, and deserves to be widely read.”
– Independent
"We love a good brain book, and The Idiot Brain by Dean Burnett might just be our new favourite.”
– Bookish

“Dedicated to every human with a brain. It’s not an easy thing to put up with, so well done.”

A Non-Fiction science book that explains nightmares, motion sickness and other everyday common experiences we have.
I added some ideas from the book that I felt they were the most interesting.


Ch 1 - Mind Controls

Over time our brains evolve and now we have the reptilian brain and neocortex.

Motion sickness -When we walk, run or crawl we produce a specific set of signals but when we are travelling by car, for example, we only get parts of signals (the shifting fluids in our ear) that we are moving and when our eyes transmit that we actually are static this confuses the brain and thinks that there is poison and needs to be removed.

Eating, when the stomach says No but our brains say Yes. - When our brain sees a desert, its pleasure pathways are activated and the brain makes an executive decision to eat the dessert and override any signals from the stomach.

If we have regular eating hours, this behaviour will be learned and the brain will create appetite even if doesn't need food.

Sleep- The pineal gland in the brain secretes the hormone melatonin, which is involved in the regulation of circadian rhythms. The amount of light that captures our eyes affects the secretion of this hormone.

REM sleep in adults is 20% and in children 80%. The main function of this is to reinforce, organize and maintain memories. When we sleep our motor system signals are weak or shut down. This is reactivated relatively fast when we woke up and if rare cases this last longer than it should, resulting in sleep paralysis.

Sleepwalking results from a disorder of this process. It seems to be linked to underdevelopment in the central nervous systems which is why it is more common in children or in the influence of stress, alcohol, medication and other disturbers.

A fight or flight response is generated when there is something wrong in the environment, even before the cortex can analyze and respond to it, the amygdala invokes the hypothalamus which in turn activates certain types of nerve systems that generate the fight or flight response such as dilating our pupils, increasing our heart rate etc.

Ch 2 - Gift of memory

Memory can be categorized into short term memory and long term memory.

  • Short term memory is anything that we hold in our minds for not more than a few seconds (that's why when you go into a room sometimes you forgot why) and is in constant use.
  • Long term memory is used to store information either voluntary (and here rehearsing is necessary) or involuntary.

Alcohol disrupts both short and long term memory. But alcoholics get used to a certain state and if they learn something in that state they can be more likely to remember the information in the same state.

Ch 3 - Fear

We have the tendency to think of potential threats even if there are none. Also, some find it difficult to embrace randomness, so they hold on to assumptions to give a sense of control in this world.

Being scared because the brain rewards them for “surviving” or “passing a threat”.

Criticism - when someone received it, his body rises the cortisol level and since this stays more in the system he is more enhanced to memories a bad even than a good one.

Ch 4 - The baffling science of intelligence

“Knowledge is knowing that a tomato is a fruit; wisdom is not putting it in a fruit salad.”– Miles Kingston

Why Intelligent people can often lose arguments? - Here is about the Impostor Syndrome.
Dunning and Kruger argued that those with poor intelligence not only lack the intellectual abilities, they also lack the ability to recognise that they are bad at something. The brain’s egocentric tendencies kick in again, suppressing things that might lead to a negative opinion of oneself. But also, recognising your own limitations and the superior abilities of others is something that itself requires intelligence. Hence you get people passionately arguing with others about subjects they have no direct experience of, even if the other person has studied the subject all their life. Our brain has only our own experiences to go from, and our baseline assumptions are that everyone is like us. So if we’re an idiot…”

Some people may see intelligence in another as a threat, so the intelligent people will present themselves in humble ways, also they are used to learn new things and because of this, they know they don’t know everything.

Less intelligent people can also lack the ability to recognize that they are bad at something.

Some intelligent people do not like to talk about abstract things just because they don’t find them useful. Western culture puts an emphasis on abstract thinking that might irritate more practical people.

Ch 5 - Observational Systems

The smell is considered to be more powerful than taste and is also the first sense to develop. We can smell around 1 trillion odours.

There was an experiment where blindfolded and nose plugged people couldn’t distinguish onion, apples and potatoes by taste.

Attention - when we are so tunnel focused that we sometimes miss something very obvious that’s going on in the external environment. In a 1998 study by Dan Simons and Daniel Levin, they approached random pedestrians with a map and asked them for directions. While the pedestrian was looking at the map, a person caring a door walked between them and the experimenter, where the experimenter quickly changed places with someone else who didn’t look or sound nothing like them. At least 50% of the time the pedestrian didn’t notice anything.

The best focus is to distract yourself from the task from time to time. Attention to a task is absolutely important but beyond a point can prove counter-productive.

Ch 6 - Personality

According to the Big 5, everyone falls between 2 extremes:

The genetic heritability of the personality is between 40-60%.

Motivation - “rewarding people for a task can actually reduce motivation for doing it, whereas giving them more control or authority increases motivation.” Also if you do something and leave it incomplete and restrict their options for resolving it. This explained why TV shows use cliff-hangers so often.

The harder the journey, the better the arrival.”

Ch 7 - Group Hug!

Facial expressions - are universal, and our brain is sensible at reading them and has proven an important attribute for our social development.

As from a study by Robert Provine suggested that we are 30% more likely to laugh at a joke if we are in a group. Being part of a group is something that our brain prioritises. We also tend to be influenced or influence others when we are in a group, about uncertain situations, and also this contributes to the bystander effect, where people are unlikely to intervene if others do not.

Ch 8 - When the Brain breaks down

This chapter is reserved for mental health - being described as patterns of behaviour or thinking that cause discomfort and suffering, or “abnormal” function from the society's view.

Depression - seems people with depression pay more attention to the negative stimuli.

“While some people do seem to develop depression out of the blue, for many it’s a consequence of too much time being hammered by life."

To get past depression takes high willpower and effort that can be channelled to something productive. For example the ‘tears of the clown’ cliché. Charlie Chaplin or Van Gogh.  

Note: Some pieces of information are left out of the book.
Get the full experience by reading it!