logo
SuperSummary Logo
Plot Summary

Idiot Brain

Dean Burnett
Guide cover placeholder
Plot Summary

Idiot Brain

Nonfiction | Book | Adult | Published in 2016

Plot Summary

The Idiot Brain: A Neuroscientist Explains What Your Head is Really Up To (2016), a non-fiction science/self-help book by Welsh neuroscientist and author Dean Burnett, seeks to explain nightmares, motion sickness, and other brain-based conundrums through rigorous scientific inquiry. The book was shortlisted for Goodreads' Science and Technology Book Award.

Burnett begins with "how the brain regulates the body, and usually makes a mess of things." He notes that in early humans, the brain functioned similar to the brain of a reptile, regulating our body to ensure survival and nothing else. However, as day-to-day survival became easier for a large portion of the human population, other parts of the brain, in particular, the neocortex, developed. The neocortex is crucial to how humans process and retain memories, particularly during sleep. It is also crucial to cognitive considerations when faced with various sensory inputs. However, the older "reptilian brain" is still a powerful force in regulating our bodies. That's why, if something happens that instinctively alarms us, the older reptilian brain will activate various "fight or flight" responses such as an increased heart rate, even if our cognitive brains tell us there is nothing to worry about.

Burnett describes the difference between short-term memories, which only last in the brain for a few seconds, and long-term memories. Long-term memories are not just places, names, and things we can always recall. They relate to a great many learned motor functions, such as playing basketball or strumming chords on a guitar. Also within the category of long-term memories are things we are "familiar" with versus things we can "recall." This is why we often recognize a person's face without remembering his or her name or where we first met the person.



Burnett differentiates between normal, logical anxieties, such as the fear of being downsized in a bad economy or the fear of physical deterioration in age, and completely illogical phobias and conspiracy theories that our brains allow us to believe despite a lack of evidence. The reason for this, Burnett writes, is that our brains are trained to reject randomness. Random information that we can't successfully synthesize to improve our survival rate wasn't much use to primitive humans. However, today we are inundated with bits of information that are unconnected, or the connections aren't clear for us. Because of our bias against randomness, the brain tries to make those connections between random occurrences in order to create or preserve a worldview that makes sense to us.

Burnett discusses the difficulties of quantifying levels of human intelligence, despite humanity's relentless efforts to do just that through IQ scores and standardized tests. He contends that one of the reasons intelligence is difficult to quantify is that there are two types of intelligence which are very different: "fluid" intelligence and "crystallized" intelligence. Burnett asserts "Knowledge is knowing that a tomato is a fruit; wisdom is not putting it in a fruit salad. It requires crystallized intelligence to know how a tomato is classed, and fluid intelligence to apply this information when making a fruit salad."

Burnett describes the five senses and why smell is so much more powerful than taste, for example. He also discusses how hearing and touch are linked because they are both "mechanical" senses activated by pressure.



Burnett observes the links between the brain and an individual's personality. The earliest evidence that the brain and personality are linked came after a man named Phineas Gage suffered a brain injury in the 1850s and experienced a dramatic personality change. Burnett also discusses particular character traits, such as anger and motivation, and how our brains perpetuate these traits based on various stimuli.

Burnett explores language and communication, discussing the extent to which our words, our expressions, and our actions are dictated by involuntary factors. Everybody wants to believe they behave with "free will." However, it takes a lot of work to train the brain to resist involuntary responses to certain social situations. For a simple example, Burnett discusses people with "good poker faces." It's not enough to try to keep a straight face. One needs to understand which facial expressions are triggered involuntarily and then focus on controlling those as well.

Finally, after detailing how normal functioning healthy brains sabotage us, at the end of the book, Burnett dives into the even bigger problems that result from brains suffering from drug addiction or mental disorders. If our brains, at their best, are less than ideal in performance, the brain of a drug addict is even harder for humans to handle.
Plot Summary?
We’re just getting started.

Add this title to our requested Study Guides list!

Plot Summary?
We’re just getting started.

Add this title to our requested Study Guides list!


A SuperSummary Plot Summary provides a quick, full synopsis of a text.

A SuperSummary Study Guide — a modern alternative to Sparknotes & CliffsNotes — provides so much more, including chapter-by-chapter summaries and analysis of major themes, characters, and important quotes.

See the difference for yourself. Check out this sample Study Guide: