High School Biology

In a long essay on the formative impact high school has on us, Jennifer Senior unpacks the science behind these crucial years:

[T]he prefrontal cortex has not yet finished developing in adolescents. It’s still adding myelin, the fatty white substance that speeds up and improves neural connections, and until those connections are consolidated—which most researchers now believe is sometime in our mid-­twenties—the more primitive, emotional parts of the brain (known collectively as the limbic system) have a more significant influence. This explains why adolescents are such notoriously poor models of self-­regulation, and why they’re so much more dramatic—“more Kirk than Spock,” in the words of B. J. Casey, a neuroscientist at Weill Medical College of Cornell University. In adolescence, the brain is also buzzing with more dopamine activity than at any other time in the human life cycle, so everything an adolescent does—everything an adolescent feels—is just a little bit more intense. “And you never get back to that intensity,” says Casey. (The British psychoanalyst Adam Phillips has a slightly different way of saying this: “Puberty,” he writes, “is everyone’s first experience of a sentient madness.”)