At the start of adolescence, the frontal cortex has more synapses than in the adult. Adolescence and early adulthood consist of the frontal cortex pruning synapses that turn out to be superfluous, poky, or plain wrong, as the region gets progressively leaner and meaner. As a great demonstration of this, while a thirteen-year-old and a twenty-year-old may perform equally on some test of frontal function, the former needs to mobilize more of the region to accomplish this.
