During adolescence, maturation (or growth) of the __­­ comes after maturation of the

With reference to the adolescent brain, the maturation or growth of the frontal lobe (i.e. prefrontal cortex), comes after or is slower than the development of the limbic system. 

The frontal lobe consists of the prefrontal cortex, premotor cortex, and the motor cortex. The prefrontal cortex is responsible for cognitive analysis, reasoning, anticipation, planning, problem solving, and impulse control. Its development lags behind the limbic system, which is responsible for emotions, behavior, motivation, long-term memory, and olfaction (sense of smell).

Because of this inequality in the development rate, together with the surge of adolescent hormones, teenagers tend to be more impulsive, rash, and emotional as the their "emotional side" develops more rapidly than their "rational, judging" side.