What does it mean to be “mature”? We usually think of it as a number—your chronological age. At 18, you can vote. At 25, your brain is supposed to be fully developed. But if you’ve ever met a brilliant person who makes terrible life choices, or a wise teenager who seems to understand the world, you know that the number of years you’ve been alive is only part of the story.
The truth is, our ability to make good decisions has more to do with our mental age than our chronological one. Mental age is a concept that looks at our cognitive, emotional, and social development, not just the number on our driver’s license. It’s a powerful lens for understanding why we make the choices we do—and how we can get better at it.
The Brain’s Uneven Development
Think of the brain as a house under construction. Different rooms are built at different times. The emotional center, the amygdala, is often the first to be fully functional. It’s the part that reacts to threats and rewards. The more rational part, the prefrontal cortex, is built much later. It’s the long-term planner, the impulse controller, the part that weighs consequences.
This uneven development explains a lot about adolescent decision-making. A teenager might feel an intense emotional pull toward a risky choice but not have the fully developed “planner” to pump the brakes. This isn’t a sign of a bad person; it’s just biology at work. The result is what researchers call “decision noise”—more variable, and often suboptimal, choices.
But this isn’t just about teenagers.
Beyond the Obvious: Cognitive, Emotional, and Social Age
Your mental age isn’t a single number. It’s more like a collection of different ages that can be out of sync.
- Your Cognitive Age: This is the part that relates to your raw intellectual horsepower. It’s about how quickly you can process information and solve logical problems. A person with a high cognitive mental age might be a master chess player, able to analyze complex situations with ease.
- Your Emotional Age: This reflects your ability to regulate feelings and manage your emotional life. Someone with a high emotional age can stay calm during a crisis and consider the feelings of others. They don’t make rash decisions out of anger or fear.
- Your Social Age: This is about understanding social dynamics and navigating relationships. A person with a high social age knows when to speak and when to listen. They are good at reading a room and avoiding awkward social blunders.
Here’s where it gets interesting: You can have a high cognitive age but a low emotional or social age. The brilliant scientist who gets conned by a scammer? Or the CEO who’s a genius in the boardroom but can’t manage their personal relationships? Their mental ages are out of balance.
The Role of Experience and Wisdom
As we get older, our brains don’t just “mature.” They also collect a vast library of experiences. This is why chronological age can matter. An older person often has a huge database of past outcomes to draw from. They might make faster decisions, not because their brain is quicker, but because they’ve seen this kind of problem before. They can rely on “mental shortcuts” or heuristics that have served them well over the years.
This shift isn’t always a sign of decline. In many cases, it’s a sign of a brain becoming more efficient. Why exhaust yourself with new research when you can tap into a lifetime of lessons learned?
The Takeaway: How to “Grow Up” Your Decision-Making
No matter your chronological age, you can always work on your mental age.
- Work on emotional regulation. Practice mindfulness and take a moment to breathe before making a choice. Ask yourself: “Is this decision coming from a place of logic or emotion?”
- Seek out different perspectives. Talk to people who have faced similar problems. An older, wiser mentor can help you see a situation from a perspective your own “mental age” hasn’t reached yet.
- Reflect on your past choices. Don’t just make a decision and forget about it. Look back at your wins and losses. What went right? What went wrong? Why? This builds the “experience library” that fuels better choices in the future.
The goal isn’t to become a single number, but to align all parts of your mental age. When your intellect, emotions, and social awareness work together, you’re not just making a good decision—you’re making a truly mature one.