Quartz opens a window on the two periods of brain development when traumatic events do the most damage:
According to Tara Swart, a neuroscientist and senior lecturer at MIT, your “terrible twos” and those turbulent teen years are when the brain’s wiring is most malleable.
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“We start to understand speech first, then we start to articulate speech ourselves and that’s a really complex thing that goes on in the brain,” Swart, who conducts ongoing research on the brain and how it affects how we become leaders, told Quartz. “Additionally, children start to walk — so from a physical point of view, that’s also a huge achievement for the brain.
Learning and understanding a new language forces your brain to work in new ways, connecting neurons and forming new pathways. This is a mentally taxing process, which is why learning a new language or musical instrument often feels exhausting.
With so many important changes happening to the brain in such a short period of time, physical or emotional trauma can cause potentially momentous interruptions to neurological development.
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By the time you hit your teenage years, the brain has typically reached its adult weight of about three pounds. Around this same time, the brain is starting to eliminate, or “prune” fragile connections and unused neural pathways. The process is similar to how one would prune a garden—cutting back the deadwood allows other plants to thrive.
During this period, the brain’s frontal lobes, especially the prefrontal cortex, experience increased activity and, for the first time, the brain is capable of comparing and analyzing several complex concepts at once. Similar to a baby learning how to speak, this period in an adolescent’s life is marked by a need for increasingly advanced communication skills and emotional maturity.
“At that age, they’re starting to become more understanding of social relationships and politics. It’s really sophisticated,” Swart noted. All of this brain activity is also a major reason why teenagers need so much sleep.