It's strongly believed that once we hit 25, the brain's plasticity solidifies. This makes it harder to create neural pathways. In turn, this can mean it's tougher to learn new skills.
Plasticity is ongoing throughout life and involves brain cells other than neurons, including glial and vascular cells. It can occur as a result of learning, experience, and memory formation, or as a result of damage to the brain.
Children's brains grow at a higher rate throughout the first 18 to 24 years of life than they do as adults. Within this extended time period, there are two periods of even more rapid brain growth; birth to 4 – 6 years and for 4 – 6 years during puberty.
Neuroplasticity, as they call it, is something you can increase for the rest of your life. That's right. So, if you're a senior, older adult, baby boomer, retiree, or just plain person who's over 60 (everyone has their own term preference), you have some control over your neuroplasticity of the brain.
Despite evidence for neuroplasticity occurring even in adulthood, the damage done by diseases such as Alzheimer's, Huntington's, Parkinson's etc remain unrepairable by the brain. This indicates that there is a certain limit to neuroplasticity, as otherwise brain injury would be overlooked in most situations.
While a younger brain is more malleable and plastic, humans are still capable of learning when they're past that age. The brain can still form new neural connections! So don't fear if you are over 18 or 25 (oh, the memories!).
Overall, the individuals with the highest IQs in this study also showed the largest changes in brain structure across the lifespan8. This could suggest that greater neural plasticity at any age is associated with greater intelligence.
Research suggests that most human brains take about 25 years to develop, though these rates can vary between men and women, and among individuals. Although the human brain matures in size during adolescence, important developments within the prefrontal cortex and other regions still take place well into one's 20s.
The brain finishes developing and maturing in the mid-to-late 20s.
The first thing you should know is that your brain is much more plastic in childhood, and plasticity declines with age. However, the good news is science has confirmed that you can access neuroplasticity for positive change in your life at any age, from birth until death.
Scientists have long understood that the brain is resilient, due in large part to neuroplasticity that allows the brain to modify connections and rewire itself. Previously, scientists thought this neuroplasticity ended early in childhood. Now, research shows that it continues even as we age.
90% of Brain Growth Happens Before Kindergarten
It keeps growing to about 80% of adult size by age 3 and 90% – nearly full grown – by age 5. The brain is the command center of the human body.
Plasticity in the young brain is very strong as we learn to map our surroundings using the senses. As we grow older, plasticity decreases to stabilize what we have already learned. This stabilization is partly controlled by a neurotransmitter called gamma-Aminobutyric acid (GABA), which inhibits neuronal activity.
The short answer is - Yes. Intelligence can be increased at almost any age. While it can be harder to learn a new language after adolescence, it is never impossible. And learning some words in another language is one very good way to improve mental ability and acuity, at any age.
Once we reach adulthood at around 25 our brain stops naturally forming new neural pathways and our habits, biases and attitudes become more set in stone and much harder to change. Nevertheless, it isn't impossible to train our brains to changing later in life and throughout adulthood.
In some people, the brain rewiring process can take a month. In others, it can take several months. The good news is that the human nervous system is neuroplastic, meaning it can change for the worse and the better. Brains that have been harmed by substance abuse can unlearn the negative behaviors.
The European study, which was released this week, found evidence that we tend to hit our cognitive maximum around age 35 and remain there until about age 45, at which point a long, slow decline takes hold.
Although you may face some extra difficulties at 30, 50 – or 90 – your brain still has an astonishing ability to learn and master many new skills, whatever your age. And the effort to master a new discipline may be more than repaid in maintaining and enhancing your overall cognitive health.
Just as you may not run as fast or jump as high as you did as a teenager, your brain's cognitive power—that is, your ability to learn, remember, and solve problems—slows down with age. You may find it harder to summon once familiar facts or divide your attention among two or more activities or sources of information.
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.
The development and maturation of the prefrontal cortex occurs primarily during adolescence and is fully accomplished at the age of 25 years.
It's because of neuroplasticity that bad habits become ingrained in your brain, valuable skills are lost as your brain declines with age, and some major brain illnesses and conditions show up in humans.
Negative factors such as stress, aging, sleep deprivation, and a sedentary lifestyle have been shown to impact neuroplasticity negatively, reducing the brain's ability to adapt and learn.
The size of the brain actually has nothing to do with one's intelligence. Studies were even done in order to come to this conclusion. Decades ago, scientists conducted testing on the person considered to be one of the most famous geniuses of all time: Albert Einstein.