Neuroplasticity drops after puberty. We can add new leaves to our neural trees after that, but new branches are rare. That’s why we often find ourselves using neural pathways built in youth despite our best intentions.
We don’t consciously rely on old pathways, and even avoid them consciously at times. But electricity in the brain flows like water in a storm, finding the paths of least resistance. Electricity flows so easily down the neural pathways built in youth that something feels wrong when we seek alternatives.
This is not laziness; it’s nature’s survival mechanism. Before there was language or curriculum design, young brains connected the neurons activated by an experience. That helped electricity flow where it had flown before, wiring a young brain to repeat experiences that felt good and avoid experiences that felt bad. Today, your verbal brain may challenge these impulses, but the flow of electricity through your well-developed pathways gives you the sense that you know what is going on. Departing from them feels not-quite-safe because old pathways built from real experience with rewards and pain.
Why Neuroplasticity Is Wasted on the Young
Reptiles leave home the instant they’re born, so they survive on the knowledge they’re born with. We mammals are born unfinished. We learn to meet our needs during an early period of dependency in which our needs are met by others. We get to wire in our unique experience instead of being born hard-wired with the experience of our ancestors.
We are born with billions of neurons but very few connections between them. This is a highly vulnerable state, so nature rewards accelerated learning. A zebra can run with the herd in a few days. A mouse can be a grandparent in a few months. The bigger a creature’s brain, the longer its childhood. We humans are born in a more helpless state than any creature. When a baby sees a hand in front of its face, it does not know the hand is attached, much less how to control it. We need almost two decades to wire in survival knowledge. We don’t notice the huge neural networks we’re slowly building, so later on we presume we can easily delete old learning and build in new learning. When this proves harder than expected, we’re mystified.
How Experience Builds Neural Pathways
Neurons connect as a result of repetition and emotion. Repetition connects neurons gradually, while emotion (positive and negative) connects them instantly. Emotions are molecules that help electricity jump the synapse between one neuron and the next. This wires us with information relevant to getting more of whatever felt good and avoiding whatever felt bad. Emotion is especially effective in a young brain, when experiences are more often perceived as “the best ever” and “the worst ever.” Over time, new experience triggers less emotion so new learning gets less of a boost.
Another boost to early pathways built comes from “myelin,” a fatty substance that coats neurons and multiplies their electrical transmission speeds. Doing things with myelinated neurons feels effortless compared to things done with raw naked neurons. Myelin is abundant in the brain before age eight, and during puberty. The repeated experiences of your myelin years form the super-highways of your brain. The emotions you repeat become the super-highways of your emotional brain.
Learning Young vs. Unlearning and Relearning
It’s obviously much easier to build good habits in youth than to replace bad habits later on. The facts about neuroplasticity are inconvenient for people who celebrate youthful follies on the presumption that there’s plenty of time to turn the ship around later on. The truth is inconvenient for people who think maturation alone can change youthful bad habits. The facts about neuroplasticity can help us make better decisions about all phases of life. It can help us accept the amount of repetition necessary for adult learning; and it can help us invest the effort necessary to give young people a good start.
About the author: Loretta Breuning, PhD, is Professor Emerita of Management at California State University, and author of Habits of a Happy Brain: Retrain your brain to boost your serotonin, dopamine, oxytocin and endorphin. She’s founder of the Inner Mammal Institute, which offers resources to help train your mammal brain for more happy chemicals