Pencil marks dot up the white door frame of my 16-year-old son’s room. The highest is at 5-feet-8 inches, and it reads “Dad.” Just last month one evening, my son stood tall against the door frame, and I reached above my shoulder. We posted it half-inch above the Dad mark. “It’s official now. I said. “You are taller than I am.”

Teenage years are gigantic transitions for the body, with surges of hormones, and bone and muscle growth. Yet what is quite not perceptible and measurable is a transition and evolution happening inside the teenage brain, something which perplexes and frustrates parents and is a new topic in brain research.

Teenage brains are different compared to adult brains, not in size but in critical neural pathways and connections. For example, take the frontal lobe — this is where the real and deep thinking happens along with judgments and realizing consequences of an action. The teenage brain lacks the pathways for the connections for the higher brain functioning. Researchers often suspect this is what leads to bad choices and cloudy judgments in teenagers.

The lack of connectedness in the frontal lobe and to other parts of the brain leads the developing teenage brain to be impulsive as well as self-centered. However, there is an upside to this — teenagers show a greater sense of spontaneity, fearlessness and curiosity.

Research is also showing that teenage brains are exceedingly susceptible to addiction. Just as a teenager’s brain is like a sponge in learning complicated algebra problems or memorizing vocabulary words, it too can easily become addicted to particular behaviors, especially smoking, using alcohol or psychotropic drugs.

Addictive habits most often begin during teenage years. Unfortunately, marketing executives at tobacco and alcohol companies know this well. Once the addiction forms, it leads to a lifelong habit. New public health policies appropriately limit direct marketing to teenagers.

Teenage behavior is influenced by not just what is happening inside the teenage brain but also what is happening outside. Laurence Steinberg, a psychology professor at Temple University, conducted an intriguing experiment. Teenagers were asked to play a “driving game” while sitting in a specialized brain scanner. They encountered a number of yellow lights. When alone, the teenager stopped as often as an adult, but when the teenager was with two or three other teenagers, the impulse to run a yellow doubled. For the adults, additional passengers did not alter the rate.

So last week, when our son proudly showed off his picture on his new driver’s license, my wife reminded him of the Tennessee law that has the graduated license not permitting him to drive with more than one non-relative teenager in the car. Such evidence-based policy, which is grounded in scientific evidence, saves lives.

Next morning at breakfast, my son proudly told his mom about being taller than Dad. Smiling, I was quick to point out, “You may be taller, but it will still take time to be wiser. … Just have to wait for that frontal lobe to be fully developed.”