Brain Research on Intelligence and Working Memory: IQ is fixed by the age of 15 – Myth:
Researchers often break total intelligence into two categories. The first they call Fluid Intelligence or IQ, which is your raw ability to perceive relationships, reason and solve problems independent of any specific experience or education. The second is the sum total of everything you have experienced and learned. This is often called Crystallized Intelligence. It is the two working together that produce your total intelligence.
While education and training can clearly improve Crystallized Intelligence, it was thought that Fluid Intelligence was fixed by some point in the teen-age years. This belief has recently been called into question.
It turns out that the biggest single component of Fluid Intelligence or IQ is the working memory capacity: This is your ability to hold and manipulate things in memory. For example, to hold all the components of a math problem in your head and solve the problem, or, in a conversation with someone, to remember a person's complete statement, analyze the statement, and come up with a logical response. It is this second component of being able to logically process the information that separates working memory from short-term memory, which you use to temporarily remember a phone number while you dial it on your phone.
Working memory capacity was thought to be fixed until researchers like Martin Buschkuehl, Susanne Jaeggi and John Jonides, all from the University of Michigan, demonstrated that with the right practice it can be increased. Increasing working memory capacity improves IQ, which makes the statement in our header a myth. Increasing working memory capacity also seems to be effective for improving behavior and academic outcomes for people with ADHD.
The Smashing Silos Research Staff