Does your brain fully mature at 25?

Humans have this weird thing of latching onto age or benchmarks of success and timelines. Whether that makes us feel more accomplished through comparison or maybe simply contextualising our feelings on “scientific fact”is comforting in a way. Brain research i.e. neuroscience and psychological studies of human development will always spark interest as they attempt to give us a better understanding of who we are but what happens when those “facts” are heavily extrapolated into conversation meaning something completely different?

“ It is well established that the brain undergoes a “rewiring “ process that is not complete until approximately 25 years of age.”

“Your brain isn’t mature until 25” - this is somewhat the new common knowledge from scientific discovery that has found its way into general conversation.Like all science discoveries it may take years for something to penetrate through the barriers of research papers and academic conversation to common conversation and dining table fun facts. This topic is no different ! Neuroscience is one of the fascinating fields that can easily capture people's attention!

In a quick google search the question of “is my brain mature” at 25? brings up...

“ It is well established that the brain undergoes a “rewiring “ process that is not complete until approximately 25 years of age.” But if you take a deeper look at the paper which google references, the actual context of this statement means something slightly different to what has taken over common talk. On social media, it won't take much scrolling to hear people say “something just feels different at 25”. So, why do many people feel the world starting to make sense after this landmark age ?

How it all started:

The leading article comes from a 2013 Review paper where researchers were trying to understand violent behaviours in adolescents. Some of the questions explored why adolescents are such risk takers. In child development, puberty is a key progress marker in maturity as changes seen are visible and linked to the hormones we all learn about growing up. In the brain, growth or rewiring is attributed to two things:

“dendritic pruning” - reducing the number of pathways by getting rid of unused pathways and
“myelination”- insulation of the neuronal cell leading to faster signalling .

The easiest way I could put it is “A spring clean and essential maintenance process of the brain happens as we age”. The review goes into further detail on the hormonal changes during adolescence such as changes in dopamine, serotonin and melatonin . MRI studies which scanned the brains of adolescents reviewed in the paper showed that adolescents use less of their prefrontal cortex in making decisions than observed in adults and were more emotionally led. The way we view age and maturity plays a part in how we observe things. If we think that our 20’s are a restart on us gaining understanding of our hormones, surrounding and personalities, with 20 at zero and 25 as 5. Is it at 5 years into “adulthood” that we begin to fully understand who we are as people and how that ties into our relationships?

“dendritic pruning” - reducing the number of pathways by getting rid of unused pathways and

“myelination”- insulation of the neuronal cell leading to faster signalling

What does brain maturation look like?

The prefrontal cortex lies just behind the forehead and plays a key role in the “brain maturation” theory. The development is also linked to the development of “myelin” which leads to faster brain signalling and growth . Growth in this case, isn't in terms of brain size as children grow in height where we expect these massive physical changes but as mentioned before it is an essential process that researchers have found takes us away from being more emotional/ hormone driven decision makers .

The brain instead goes through a flux in maturation and relative size where myelination will increase “size” as well as the loss of neurons. Brain size is essentially determined by maturation which “increases” size by reducing pathways and increasing processing speed if we describe the brain as a computer network and ageing that is essentially the loss of matured pathways and connections.

The nuanced meaning of brain growth and impact on society

In researching for this article I came across a blog post " Master you metaphors " that highlights the importance of not over-using metaphors to "translate" scientific evidence to the general public.

Rewiring as a term to explain things about the brain is useful but does it give the full picture? In a sense it explains that things move from one place to another and therefore making a “better” brain from something that was seemingly wrong ( this is open for interpretation) . In the real world, rewiring occurs when something is wrong. You wouldn't rewire your house if it wasn’t done correctly the first time. Describing the brain fully maturing ties into the human sense of seeing changes similar to that of puberty as a way to describe these final stages. What it actually means may be evidenced one day by research but the feeling of maturity and what it is, will forever remain open to societal context.

Science “fact” is weaponised in society as a whole and something the science community has come to struggle with. Those examples give quite a lot to think about, which is especially important for the topic of brain maturation. Maturity is somethings that can only partially be defined by brain evidence as the nuances around what counts in different societies is yet to be understood.

Food for thought: How do we infer from scientific evidence accurately in daily conversation?

Thinking of the brain as this static machine allows people to forget that human beings don’t work as the systems we have created but instead as a whole with many pieces we are yet to understand. We take in information at the same time hormones are released and emotions are expressed, therefore pinpointing maturity as a single sign of what has been evidenced doesn’t do the human body justice and frankly most scientific findings can only highlight the bits we have been able to measure and rationalise. The beauty of our full-selves lies in the unknown and learning something new everyday !

TCIM continues to be a platform to present the “FACTS” but open to a challenge and discussion of understanding. As said perfectly in the Master you metaphors blog,” science is done by humans to better understand humans but not without the bias “ making it as I will add a perfectly imperfect system to not put context when it comes to studies on behaviour and even health and how we occupy space .