Brain Rules: 12 Things we Know on How the Brain Works


12 brain rules

Our brains are amazing organs — they allow us to infer information, get us to safety, solve problems, and imagine things. Some of these feats help save our lives, others merely assist in saving our face. We do dumb things, too, but we have something that only humans have — symbolic reasoning.

    While there's a lot we still don't know about the three-pound gray matter that sits as the body's command center in its armor, the hard skull, we do know a few things that can help us make better use of it. But before reading further, let's all take a walk around the office, house, or block.

    Movement makes us think better. Moving around, 10-12 miles a day between walking and running, is how our ancestors survived and evolved. In Brain Rules John Medina says, “Though a great deal of our evolutionary history remains shrouded in controversy, the one fact that every paleoanthropologist on the planet accepts can be summarized in two words: we moved. A lot.”

    Among the things we do know about how the brain works, 12 stand the test of time:

Brain Rule #1 — survival, the human brain evolved, too

    The brain appears to be designed to solve problems related to surviving in an unstable outdoor environment, and to do so in near constant motion.

    In fact, we adapted to change itself. After we were forced from the trees to the savannah by climate swings to find food. Switching from four to two legs, our energy freed up to develop the complex brain. Crawling and climbing helped our convergence for when we acquired a different view.

    Our three brains are the “lizard brain” to keep us breathing, a brain like a cat's, and the thin layer we call “cortex” on top to power human intelligence. Symbolic reasoning is a talent only humans have. Maybe trying to understand each other's motivations and intentions helped along. The benefit was our ability to get together and act as groups. (With mixed reviews to this day.)

Brain Rule #2 — exercise boosts brain power

    If our operating system was to develop, walking and moving round 10-12 miles per day helped it along. Want to improve thinking skills? Move more. Exercise gets blood to our brain, which delivers glucose for energy and oxygen to mop up the toxic electrons left over from the process. It also stimulates the protein that keeps neutrons connecting.

    Two times a week of aerobic exercise cuts in half the risk of general dementia, and the risk for Alzheimer by 60 percent. Getting a dog is a good way to ensure long walks twice a day. And we get a loyal companion.

Brain Rule #3 — sleep well, think well

    Loss of sleep hurts attention, ability to make decisions, working memory, mood, (increasingly essential) quantitative skills, logical reasoning, and even motor dexterity.

    When we're asleep, our brain is quite active, maybe replaying our learning of the day. What happens in our brain is fascinating — cells and chemicals in constant tension between going to sleep and staying awake. Saying, “get some sleep” seems simple. 

    But some of us require more sleep than others. We do all have one thing in common — the biological need for an afternoon nap. Research has found that a 20-minute nap between 2-3pm is optimal.

Brain Rule #4 — stressed brains don't learn the same way

    Stress is our built-in defense system to avoid danger. Our brain's release of adrenaline and cortisol are life saving. Nature designed this kind of stress to be temporary. When it becomes chronic, adrenaline scars our blood vessels, which can cause heart attack, stroke, or do more damage to our ability to learn and remember.

    It's the one thing we don't want to keep long term, because it's designed to be a short-term response. A feeling of helplessness is the worst kind of stress. Emotional stress has the worst impact on our ability to function well.

Brain Rule #5 — every brain has different wiring

    We're a combination of genetics and environment. Each of us develops regions of the brain differently based on what we do and learn in life. At two and in our teens, neurons experience a growth spurt and pruning, but no two people store the same information the same way… and in the same place.

    IQ is not the only kind of intelligence, many more are invisible in its tests. So not so good a measure.

Brain Rule #6 — we don't pay attention to boring things

    Hence why playfulness, humor, novelty, and emotion work. But 10 minutes is all we have. After that, forget about it.

    Whether our brains are different because or gender or not, which is still an open question, we're all better at seeing patterns and abstracting the meaning of an event. This is our faster System 1 at work to help us make sense of things on the spot.

    All those job descriptions that talk about ability to multitask demonstrate a failure to understand how our attention works — we can focus only on thing at a time. Even computers start rendering in the background when we try to open too many apps at once.

Brain Rule #7 — memory, repeat to remember

    Memorizing things works. Because our brain collects memory in busy work spaces that function like temporary way stations, repeating things helps us store them more permanently. The best way to make long-term memory more reliable is to introduce new information gradually, then repeat at timed intervals. Long-term memory is a conversation between the hippocampus and the cortex.

    Our process for making memories is similar to how we program artificial intelligence using machine learning. We have many types of memory systems. Explicit memory follows four stages — encoding, storing, retrieving, and forgetting. Incoming information gets broken down and dispatched to different parts of the cortex for processing.

    Each of us has only an approximate view of reality — we mix new knowledge with past memories to form our worldview.

Brain Rule #8 — sensory integration, stimulate more of the senses

    We take in information from different paths — sight, sound, touch, taste, etc. create electrical signals that go to different parts of the brain to reassemble and give us a sense of what happened. Past experiences seem to influence how we reconstruct reality. This is why two people witnessing the same event will have different stories.

    Our senses work together, which means that learning something through more than one method is best. Smell is the strongest recorder of past memories — it has a direct line to the amygdala, which supervises emotion.

Brain Rule #9 — vision beats all other senses

    It takes up to 50 percent of our brain's resources and is not even 100 percent accurate. That's because vision has many steps. Our retina assembles protons into streams of information that look like a movie. The visual cortex takes them in to process as motion, color, etc. Then we piece everything together in what we call sight.

    Pictures are the best way to remember.

Brain Rule #10 — music boosts cognition

     Formal musical training improves intellectual skills in several cognitive domains, including the social sphere. This means a finer ability to detect emotion in speech, improving cognitive empathy and other social behaviors at any age.

    Music boosts spatial-temporal skills, vocabulary, picking up sounds in noisy environments, working memory, and sensory-motor skills.

Brain Rule #11 — gender, male an female brains are different

    The X chromosome is a cognitive “hot spot” that carries a large percentage of genes that manufacture the brain. Females have two, males have one (and one acting as backup.) If you've wondered, are men's and women's brains different? Yes, they are in structure, but we don't know if this has significance.

    Women's genetics are more complex as the active X chromosomes are a mix of Mom's and Dad's. Men's X chromosomes all come from their mother and their Y chromosome carries less than 100 genes (the X has 1,500.) Our response to stress is different women remember the emotional details, men get the gist.

Brain Rule #12 exploration is powerful and natural to us

    Watch a baby interact with the environment and you see how we learn. We observe, formulate a hypothesis, experiment, and draw conclusions. It's one and the same with the scientific process. Specific parts of the brain are in charge of each phase.

    The right prefrontal cortex looks of errors in our hypothesis, as in “that snake is going to bite us,” a region next to it tells us to “Run!” for our lives. Mirror neurons help us become better negotiators, as they allow us to recognize and imitate behavior.

    We can learn by experimenting at any age, because parts of the adult brain remain malleable like a baby's — we retain the ability to create neurons throughout life.

    Of all the things we know about the brain, these 12 principles will help us improve how we do things to make the best use of our operating system.

Three ways to use this knowledge

    1. Move around more throughout the day — park at the end of the lot, take stairs where possible, have walking meetings, join a hiking, walking, running, or any outdoors activity you can on weekends or early in the morning.

    If you live in Europe, congratulations, you may able to take more public transportation, bike, train, or even walk to work. If you live in a city that is well connected through reliable public transportation, you can do the same.

    2. Experiment with your circadian rhythms — often referred to as the “body clock,” the circadian rhythm is a cycle that tells our bodies when to sleep, rise, eat—regulating many physiological processes. We “open” and “close” at regular times during the day (circa means around, diem means day.) They're built-in, and they adjust to the local environment via external cues. But we do have predictable patterns.

    In When, Dan Pink reports on research that helps us figure out the optimal times for us to focus our attention to get which things done, when to sleep, and how to nap. During the day, we can pin down the best times to concentrate and use our sharpest analytic capacities, ideate, or let our imagination loose on a question or problem to get to an insight, and rest. Ready?

    To understand where to optimize your efforts, you need to figure out what time you go to sleep, what time you wake up, and the middle point. For example, you go to bed at 10:30pm, wake up at 6:30am, your midpoint is 2:30am. Then go find yourself on the Roenneberg chart below.

  Midpoint of sleep

    Then adjust your tasks accordingly. Morning people (larks), do analytic tasks early in the morning, insight tasks in late afternoon/evening, and make decisions early in the am. Early birds can go to mid-morning for analytic and otherwise follow the same patterns as larks. Owls should defer analytic tasks to and make decisions in late afternoon and early evening, insight tasks in the morning.

    Everyone should prepare to make a good impression in the morning. Getting at least 7 hours of sleep is important. Naps are very valuable. Taking a 20-minute nap between 2-3pm has been proven to recharge us.

    3. Sequence work, rather than multitasking — in my linguistic analysis of job descriptions, the use of the word “multitasking” is both a cultural/social signal and lazy. It's a mechanical way organizations use to regard work as industrial effort, which creates busy bodies and activity. But we know activity does not equal results. One good clue as to the culture is to calculate the number and format of meetings and analyze results or outcomes.

    It's lazy because no organization wants to create the perception people slack there (do your deep thinking in your spare time, already!) Broader culture dictates that hustling, grinding, and gritting are good and does not distinguish when it's appropriate to do so — timing and purpose are everything, in work, and in life.