Some scientists believe that fluid intelligence doesn’t have anything to do with IQ or being “book smart†and more to do with the ability to look at information previously accepted as reality and searching for different answers. Some would use the ‘politically correct’ term “thinking outside the box.†Static intelligence is just the opposite, the inability or unwillingness to go against established beliefs.
Those who go outside the normal paradigm of study or belief are labeled with such titles as kook or wacky, yet throughout history those “kooky†scientists have been the ones who have opened up new areas to research – examples: Einstein, Pasteur, Edison, Galileo, Da Vinci. Their peers ridiculed these great scientists because they defied conventional ideas in search of new approaches. 
Everything we think or do as adults is predicated by what he learned as a child – through what our parents taught us, from what we learned in school or books, and from things we experienced outside home and school. A person’s fluid intelligence is determined by how much people are able to adapt or revise their previously learned concepts to form new ones. Most people move from fluid to static intelligence from time to time.
The Cattell-Horn theory, put together by psychologists Raymond Cattell and John Horn, suggests that intelligence is composed of a number of different abilities that interact and work together to produce overall individual intelligence. Cattell defined fluid intelligence as, “…the ability to perceive relationships independent of previous specific practice or instruction concerning those relationships.” He believed that fluid intelligence is the ability to think and reason abstractly to solve problems. This ability is considered independent of learning, experience, and education.
Fluid intelligence, like reflexes, is at its peak in young adulthood and then declines steadily as we age. Researchers suggest this decline may be related to local atrophy of the brain in the right cerebellum, a lack of practice or age-related changes in the brain may contribute to the decline. It involves the dorsolateral prefrontal cortex, the anterior cingulate cortex, and other systems related to attention and short-term memory.
Recent study, from the University of Michigan found that healthy young adults, “who practiced a demanding working memory task for about 25 minutes per day for between 8 and 19 days, had statistically significant increases in their scores on a matrix test of fluid intelligence taken before and after the training than a control group who did not do any training at all.†A separate study in China had the same results.
This is Ron White, two-time USA Memory Champion , memory training expert, and memory keynote speaker.
Sources:
Wikipedia – Fluid and crystallized intelligence: http://en.wikipedia.org/wiki/Fluid_and_crystallized_intelligence
PubMed.gov – Working memory, short-term memory, and general fluid intelligence: a latent-variable approach: http://www.ncbi.nlm.nih.gov/pubmed/10513398
National Academy of Sciences – Increasing fluid intelligence is possible after all, by Robert J. Sternberg: http://www.pnas.org/content/105/19/6791.full
Ask.com Psychology – What is Fluid Memory?: http://psychology.about.com/od/findex/g/def_fluidintell.htm
Science Daily – Brain-Training To Improve Memory Boosts Fluid Intelligence: http://www.sciencedaily.com/releases/2008/05/080505075642.htm