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What's Wrong with Teenagers?

When I was in school, I associated science with dissecting frogs and figuring out which pea pods would grow green and which ones red. I thought once I graduated I would never think about science and I certainly wouldn't get excited about it. What has gotten me really excited is the new science revolving around brain development, and in particular adolescent brain development. Neuroscience has opened the brain for study with the use of Magnetic Resonance Imaging (MRI), Functional MRI (fMRI) and Positron Emission Tomography (PET). This technology allows scientists to study the living human brain. This rocks my world not only as a parent of a teenager but as a criminologist.

Teenagers are strange creatures. Most of us don't need brain scan technology to tell us that. Every generation has their nuances, but common elements include scattered thinking, impulsivity and a confrontational style of communication. I often find myself staring at my son in disbelief thinking, "Is this situation really happening or am I stuck in some bad 60s movie?" Those who work with juveniles in the criminal justice system have it especially hard as they deal with teens that have made some very bad adult decisions and are stuck between childhood and adulthood in a destructive way. The exciting thing about the emerging brain science is it can help us guide teens through. I heard in a workshop this weekend, "We need to be their auxiliary prefrontal cortex."

Key Findings

  • Activity in the teen brain is similar to the 0-3 fundamental development years
  • The brain might not fully develop until 25 years old
  • The brain develops by trial and error
  • Hormone type and level influence choices and behavior
  • Trauma affects brain development
  • Adults should expect teens to act like teens

Basic Science Stuff

The human brain weighs about three pounds and has two halves connected by trillions of connectors which act as information highways. It is divided into sections. Several sections are the focus in teen brain development:

This section is the hard lump at the top of the neck. It is the last area to develop and often isn't fully developed until the mid-20s. It is linked to movement and types of social cognition, such as reading social cues. In teens, this translates to frustrations over teen perceived inability to say thank you (appreciation), be on time (courtesy), offering to help out (empathy) and incessant talking about themselves (self-centeredness).

This section works with another section of the brain to help coordinate short term memory, emotion (gut reaction) and intelligent responses. In teens, this is not yet well coordinated translating to forgetfulness and a then a gut reaction by an under-developed intellect. This creates hundreds of arguments over taking out the trash and also adds to the juvenile justice worker's frustration over inappropriate teen responses to what seem like minor requests.

The hypothalamus regulates sleep, sex drive, ovulation, thirst and hunger. This development explains why teens seem to never go to sleep (they are wired to not be sleepy until after 11pm) and why sex is so all encompassing (hormones are increasing and new research points to the possibility adolescence is a critical period for the survival activity of mating).

Referred to as the primal section of the brain, or the reptilian brain, the amygdala represents the most ancient part of the brain. It helps prompt gut impulses and is responsible for survival reactions, such as fight, flight or freeze. Teens rely on this section more than adults who rely on the next section for responses to the world around them.

Pre-frontal Cortex (PFC)
This section of the brain appears to go through the most changes during adolescence. Like the cerebellum, it doesn't fully mature until the mid-20s. The PFC affects behavioral and cognitive functions and is responsible for inhibiting inappropriate behavior, initiating appropriate behavior, organizing things, making decisions, setting priorities, empathy, insight and judgment. With the PFC being in charge of all these things and teens having not-fully developed PFCs, it's easy to see how teens can make impulsive, gut-emotion based poor decisions and why it is so important for adults to help them with their reasoning and their choices.


Along with the developing brain, an increase in hormones during adolescence affects teen cognition and behavior. During infancy, estrogen and testosterone surge. Then they disappear for a while, but come back with a vengeance around 8 (females) and 10 (males). Receptors are sprinkled throughout the developing brain, such as in the cortex, cerebellum, amygdale and the hippocampus. The variation in amount of hormones in each gender affects brain development in ways which influence behavior. The physical maturation hormones bring about also affect adult's perception. For example, it is easier to treat a 6'2", deep-voiced 15 year-old male with size 12 shoes like an adult than a 5'2", high-toned 15 year-old male with a size 5. This also affects our perception of culpability especially in response to criminal activity.

Other Factors

Many teens are risk-takers and this often results in law enforcement trouble. Teens hate to be bored. The production of dopamine in a teen's brain and the high they experience drive many of their behaviors. They crave excitement. Another good quote I heard at my workshop was, "Teens don't think they are immortal. They know they're mortal. They just don't prioritize it." Teens get bored easy and often do high-risk things when they experience it. Interesting though, research has found the one risk not rewarding to the teen brain embarrassment. This has implications in a number of criminological practices, including re-integrative shaming.

Another important factor in teen brain development is the affect of trauma. A one time traumatic event, such as a sexual assault, or reoccurring trauma, such as abuse or neglect, can change the brain and affect development. Neuroscience shows how trauma can change the size of the parts of the brain, levels of hormones and delay maturation. Teens who deal with trauma often have an exaggerated fight, flight or freeze response to perceived danger due to utilizing the amygdala for emotional response because of an under-developed PFC.

Science allows us to see the functioning of the teen brain. Having an understanding of this brain development allows us to respond to teen behavior in a way that will assist in maturation, essentially being their auxiliary pre-frontal cortex. Some things we, as adults need to understand are teens:

  • Need the "arguing/complaining" to feel they are in a safe relationship in which to be heard
  • Are going to second guess, negotiate, refuse to concede and discuss at length
  • Are going to forget, get distracted, deprioritize and challenge boundaries
  • Are going to be emotionally charged, befuddled and on edge

Adults can:

  • Be understanding of a teen's point of view
  • Ask for good behavior rather than demanding it
  • Make one request at a time
  • Look for specific things to praise
  • Say positive things
  • Be firm but friendly
  • Set boundaries with clear consequences instead of trying to convince teens to make good decisions

The good thing is 90% of teens traverse their adolescent years with success. It's nice to keep that in mind since those we are working with make up the 10% that are struggling. When you're surrounded by those who are not being successful, it's easy to forget about the majority that are making good decisions and growing up healthy. I'm grateful to brain science for allowing me to rethink the way I perceived my own teen, as well as, those I work with. Hopefully with this new understanding, I will be more effective in being the auxiliary pre-frontal cortex for the teens in my life.