What is fluid-G?

G stands for General Intelligence which has two discrete factors:  

Fluid Intelligence (fluid-G) and Crystallized intelligence (crystallized-G)

Fluid vs Crystallized intelligence: fluid-G generally correlates with measures of abstract reasoning and problem solving. It includes such abilities as pattern recognition, abstract reasoning, and puzzle-solving. It is the capacity to think logically and solve problems in novel situations. This set of skills or gifts is independent of acquired knowledge. They constitute and express one’s ability to analyze novel problems, identify patterns and see the relationships that underpin these problems, and the extrapolation of these using logic.

fluid-G is necessary for all logical problem solving, e.g., in scientific, mathematical and technical problem solving. 

crystallized-G correlates with abilities that depend on accumulated knowledge and experience, such as vocabulary, general information, and analogies. It's the ability to acquire and use skills, knowledge, and experience. It does not precisely equate to memory, but it does rely on accessing information from long-term memory. Knowledge increases an individual’s crystallized-G.

Crystallized intelligence is one’s lifelong accumulated information, demonstrated and quantifiable largely through one's vocabulary and general knowledge. What do you know? Fluid and crystallized intelligence interact, working together to produce an individual’s overall capacity to accumulate (store) accessible information and ability to synthesize it, creating (discovering) new information — a person’s G.

Think of crystalized intelligence as the ability to store and recall information and fluid-G as CURIOSITY. Neither of these sets of abilities are innately fixed or limited. Both fluid-G and crystalized-G are malleable and continually change throughout one’s life.

Education, brain training exercises, and being present improve one’s G.