Why it’s Smart to Know Your Brain’s History

Brain history title image

The reason I’m going to share with you the history of the human brain is because it has practical implications. We can live better and do better in school if we understand this history.

Essentially, you have a reptile’s brain, wrapped in a mammal’s brain, wrapped in a human’s brain.* You might think of it as an evolutionary turducken. The outer layer is relatively new, the inner layers are older. When humans evolved the high level of intelligence they have, they didn’t start from scratch and grow entirely new brains, because that’s not how evolution works.

Evolution always builds on what was there before: Fish flippers became reptile limbs, dinosaur arms became bird wings, and primitive brains became advanced brains. So our incredible human brains are composed of these two older layers, and a new layer–the wrinkled outer layer we’re all familiar with. And this isn’t just fascinating; it’s really important. The outer layer–the cerebral cortex–is what gives us the abilities that define our species: intelligence and creativity.

All three brain-layers are used daily and generally work together. But when we feel threatened in some way, the cortex shuts down, partially or completely, and we’re left with the two inner layers–the mammalian and reptilian brains. Likewise, when we have urgent physical needs that aren’t being met, the mammal’s brain shuts down and we’re left with the reptile’s brain. This is, to be sure, an oversimplification, but it’s a very helpful model.

This model tells us that if we want to think and act our best–if we want to live up to our human potential–then we need to first address our physical and emotional needs: air, water, food, shelter, safety, comfort, companionship, and love. If we don’t meet these needs, then the older parts of the brain are likely to take over. Understanding the brain’s layers can help us manage our emotions and our actions.

Let’s think about some examples. Consider how difficult it is to do a math problem when you really, really have to go to the bathroom. Or consider what you would be able to focus on if you hadn’t eaten for three days: You’d probably be thinking about food and how to get some. Could you comprehend a Shakespearean sonnet while drowning? When your physical needs aren’t met, nearly all your brain power gets devoted to meeting them.

This phenomenon is probably best illustrated by the fight-or-flight response. Danger causes adrenaline to pump through our bodies and brains, preparing us for action, but it also hinders rational thinking and our ability to consciously choose our actions or even see possible options. Danger makes us act on instinct: We prepare to either run or fight for our lives.

Thankfully, the modern classroom isn’t filled with poisonous snakes and man-eating tigers, so students can learn in a relatively safe environment. If that’s the case, then why do so many students suffer from test anxiety? Why are so many students terrified of public speaking? Why are so many students afraid to ask questions in class?

The truth is that these are complicated issues, and there is no single answer to the questions I just asked. Test anxiety and fear of public speaking usually stem from a lack of effective preparation. The fear of asking questions is usually related to having a fixed mindset. But aside from these common sources of nervousness and fear, there are some other, more surprising culprits to be aware of.

Humans have a core set of biological needs that must be met, to one degree or another, in order to function at our best. This wisdom was popularized years ago in Abraham Maslow’s “Hierarchy of Needs:”

Maslow's Pyramid

When the foundation of this pyramid isn’t well-established, we’re more likely to operate out of the older, inner layers of our brains. In fact, when the base of this pyramid is weak, our brain health is generally sub-optimal. This manifests in a number of ways: anxiety, difficulty focusing, trouble remembering information, or reduced self-discipline. None of those effects are academically helpful.

Moving up the pyramid, we see that social needs are also critical. When humans receive no social support or companionship, they become depressed and lose motivation. When we’re embarrassed or ostracized, we struggle to think clearly. Conversely, when people feel a strong sense of love and belonging, they become better at problem-solving, better at dealing with life’s difficulties, and more willing to take necessary risks.

Students have great difficulty focusing on schoolwork when they’re being harassed or bullied. It’s important for students of all ages to feel comfortable at school, so they can focus on learning and feel confident enough to try new things. If your child is struggling academically, it would be smart to check in with him on social issues. Of course, it would also be smart to check in on how he’s studying. Just be aware that talking with your child about school is a delicate balancing act.

When the lower levels of Maslow’s pyramid are strong and solid, we’re much more likely to use the outermost layer of the brain. This could not be more important. The cerebral cortex is responsible for many critical functions, including language, abstract thought, imagination, long-term planning, and morality. Activities such as creative problem solving, focusing on a writing project, paying attention to a lecture, carefully reading instructions during an exam, and time-management all require the use of this part of the brain. Difficult mental activities simply cannot be done when the cortex isn’t in charge.

The older parts of the brain are more automatic, unthinking, and emotional. They contain basic animal instincts. We’ve retained those instincts because they’re sometimes helpful. Oftentimes, though, they get in the way of rational plans that we choose during our calmer moments. By taking care of your inner animal, you can keep the thinking part of your brain in the driver’s seat.

*By mammal’s brain I mean the layer added during mammalian evolutionary history. Mammals’ brains also contain within them the reptilian brain. And really, the human brain is the combination of all three. Many mammals have the third layer – the cortex – as well, but ours is much, much thicker.

 

Further Reading

Medina, John. Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School. Pear Press, 2008.

“The Human Brain.” Discovering Psychology. The Annenberg Learner. http://www.learner.org/series/discoveringpsychology/brain/brain_flash.html

“The Evolutionary Layers of the Human Brain.” http://thebrain.mcgill.ca/flash/d/d_05/d_05_cr/d_05_cr_her/d_05_cr_her.html

MacDonald, Matthew. Your Brain: The Missing Manual. O’Reilly Media, 2008.

Navarro, Joe. What Every BODY is Saying: An Ex-FBI Agent’s Guide to Speed-Reading People. William Morrow Paperbacks, 2008.

Image Credits

GreenFlames09. “Brain.” https://www.flickr.com/. Creative Commons 4.0.

Finkelstein. “Maslow’s Hierarchy of Needs.” Wikimedia Commons. http://commons.wikimedia.org/wiki/File:Maslow’s_hierarchy_of_needs.svg

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