Free Think Smart: A Neuroscientist's Prescription for Improving Your Brain's Performance by Richard Restak Page B

above, of coming up with a universally acceptable definition of intelligence. But rather than allowing ourselves to become entangled in knotty and ultimately fruitless attempts to define intelligence, let’s concentrate instead on identifying some of the traits commonly recognized to be associated with heightened intelligence and enhanced mental abilities.
    • Mental acuity (fluid intelligence). Fluid intelligence comes into play whenever we solve a problem by employing a free-form approach rather than relying on previously acquired knowledge. For instance, if someone with no medical training is forced under emergency circumstances to tend to a sick person, the amateur caregiver must rely on a seat-of-the-pants approach to compensate for his or her lack of medical knowledge. This fluid intelligence is processed by the prefrontal lobes, one on each side of the brain. Damage to these areas exerts a devastating effect on fluid intelligence and results in severe impairments in problem solving. The person with frontal lobe damage can lose this ability to come up with improvisational approaches, less than perfect but best under the circumstances, to problems and challenges.
    • Knowledge and information (crystallized intelligence). In contrast to fluid intelligence, crystallized intelligence relies on previously acquired knowledge. When a trained physician diagnoses and treats an illness, she’s relying on crystallized intelligence: the practical application of her years of medical training. In contrast to the person with no medical training, she doesn’t take a tentative unstructured approach to her patient’s illness; her store of knowledge and information allows her to respond quickly and decisively. The greater that store of knowledge, the greater her control over the treatment situation. One more distinction from fluid intelligence: crystallized intelligence isn’t as affected by brain damage either in the prefrontal lobes or elsewhere.
    • Memory. Learning new information isn’t helpful unless it can be recalled later. Anything that increases one’s memory powers increases access to everything learned.
    • Curiosity. The more curious we are, the more we learn.
    • Speed of information processing. In general, faster mental speed is associated with higher intelligence. Typically we describe someone who isn’t very intelligent as “slow”—an intuitive appreciation of what experimental psychologists have found in reaction time tests. In one test measuring speed of information processing called the odd-button-out test, the subject rests a finger on a “home button” while looking at a screen showing three target buttons. If two of the target buttons illuminate, the subject moves his finger from the home button and presses the third button on the screen as quickly as possible. If only one target button lights up, the subject presses that button. People who respond the quickest in the odd-button-out test have an above-average IQ.
    • Ability to think in abstract terms unrelated to specific applications. The increase in IQ in industrial countries over the last hundred years is the result of a progression from concrete to abstract levels of thinking and understanding (i.e., a chair and a table are similar not because they both have four legs—a concrete response—but because they are both items of furniture).
    In addition, Flynn suggests that when speaking about intelligence, we “dissect it into solving mathematical problems, interpreting the great works of literature, finding on-the-spot solutions, assimilating the scientific worldview, critical acumen, and wisdom.”
    Enhancing brain function involves the adoption of a specific mental attitude that, according to Flynn, involves internalizing “the goal of seeking challenging cognitive environments—seeking intellectual challenges all the way from choosing the right leisure activities to wanting to marry someone who is intellectually stimulating. The best