Ever wonder why your teen makes irrational or illogical decisions? You’ve explained the dangers of reckless behavior, vaping, drinking, and mindless scrolling, but your warnings go in one ear and out the other. When a peer suggests they ride bikes in a construction zone or stay up late playing online games, their sense of reasoning disappears.

Brain Science

Part of the answer has to do with brain science. 

Brains aren’t fully developed until mid-20s. Before then the prefrontal cortex, the logical, reasoning portion of the brain, doesn’t work to full capacity. Rather, someone with an immature brain is more prone to make decisions with their amygdala, the fight-or-flight, gut instinct, emotional portion of the brain. 

A University of Rochester Medical Center article explains it this way: 

It doesn’t matter how smart teens are or how well they scored on the SAT or ACT. Good judgment isn’t something they can excel in, at least not yet.

The rational part of a teen’s brain isn’t fully developed and won’t be until age 25 or so.

In fact, recent research has found that adult and teen brains work differently. Adults think with the prefrontal cortex, the brain’s rational part. This is the part of the brain that responds to situations with good judgment and an awareness of long-term consequences. Teens process information with the amygdala. This is the emotional part.

In teens’ brains, the connections between the emotional part of the brain and the decision-making center are still developing—and not always at the same rate. That’s why when teens have overwhelming emotional input, they can’t explain later what they were thinking. They weren’t thinking as much as they were feeling.

Because teens aren’t as adept at thinking about consequences (if I do this, then this will happen), they’re more likely to make impulsive decisions. When they’re tempted, they go for it.

When I explain brain science to ninth graders, I put a piece of chocolate next to me and say, “I’m a chocoholic. When I see chocolate, my mouth waters, and I automatically grab it. My brain has been programmed, or wired, to pick it up and eat it. It’s instinctual.” My brain craves the dopamine hit from the smell and taste of chocolate. 

The brain forms neural pathways when we repeatedly make the same choice. The behavior becomes automatic. When I first tasted chocolate, I found it pleasurable. The next time I saw a piece of chocolate, I remembered how yummy it was and had another piece. Years later, the response is involuntary. See. Reach. Eat. Dopamine. Pleasure. 

Teens are more likely to develop habits which become addictions because their brains are still forming. Those neural pathways follow them into adult years. Therefore, it’s more important for preteens, teens, and young adults to make healthy choices, to condition their brains to choose wisely, than it is for adults. 

Thankfully, the brain is neuroplastic. It’s pliable. The neural pathways are not permanent. 

That means I can change my automatic response to chocolate. I can break the pattern and make a different decision when chocolate stares at me. 

So can our children.

How does this information help us parent our teens? 

The University of Rochester article lists these suggestions:

• “Discussing the consequences of their actions can help teens link impulsive thinking with facts. This helps the brain make these connections and wires the brain to make this link more often.
• Remind your teens that they’re resilient and competent. Because they’re so focused in the moment, teens have trouble seeing that they can play a part in changing bad situations. It can help to remind them of times in the past that they thought would be devastating but turned out for the best.
• Become familiar with things that are important to your teens. . . . Showing an interest in the things they’re involved in shows them they’re important to you.”

We can help preteens and teens strengthen their prefrontal cortex by teaching them to resist temptation, get enough sleep, eat well, and exercise. When they have a choice to make, walk them through the options and the consequences of each one. Regularly ask your child how you can help them and listen to them when they confide in you.

If you think your preteen or teen made a rash decision, especially while under stress or pressured by peers, you’re probably right. Rather than get angry because they haven’t employed common sense decision-making skills, remember that their prefrontal cortex is still developing. Take a deep breath and speak calmly.

If you believe your child has a compulsion or addiction, don’t expect them to have the skills or ability to walk away. Those pathways are deep. Their body craves the dopamine it’s accustomed to. They need to learn to adapt their response to the enticing behavior.

I learned that one bite-sized piece of chocolate is my limit. This conclusion required reasoning skills I exercised over time. This revelation gives me hope. If I can do it, so can my children. Yours too!

Barb Winters is a Sexual Risk Avoidance Specialist, author of Sexpectations: Helping the Next Generation Navigate Healthy Relationships, and founder of Hopeful Mom. In March 2025, Barb was named in the list of 20 Inspiring Women Dedicated to Making Life Safer for Kids.