Sounds like some reporter (or at least the editor that wrote the headline, and probably even the neurologist quoted below) wasn't paying attention in Intro Psych when they went over Correlation Doesn't Equal Causation. What people constantly forget is that "cognitive reserve" (a.k.a. premorbid IQ) is not something that you attain during the educational process. Going to school for more years doesn't make you any smarter (i.e., cognitively efficient/better at learning new things). People who are smarter go to school for more years. The reason people drop out of high school is because they have low IQs. The reason high school graduates make more money than drop outs who later earned GEDs is that GED grads have lower IQs than high school grads. Harvard graduates are successful in life because Harvard only admits exceptionally high IQ students. The students do not attain even higher IQs after going through four years at Harvard.
All this study shows is that people with higher premorbid IQs (e.g., college grads) are better able to recover from brain injuries than high school dropouts. Recovery from brain injury involves learning new ways to live in the world, and people with higher IQs are better at learning new things.
The point about Alzheimer's is interesting and has been known for years. The higher your IQ, the less likely you are to develop Alzheimer's. Crudely, people talk about high IQ folks having "more brain to burn" during the inevitable aging/dementing process. They are dementing, too, but they have farther to fall before becoming disabled by their brain disease and probably compensate better. They also are less likely to smoke, be drug/alcohol dependent, or to have suffered head injuries -- because they have higher IQs -- all of which are risk factors for Alzheimer's.
Education May Help Insulate The Brain Against Traumatic Injury
A little education goes a long way toward ensuring you'll recover from a serious traumatic brain injury. In fact, people with lots of education are seven times more likely than high school dropouts to have no measurable disability a year later.
"It's a very dramatic difference," says Eric Schneider, an epidemiologist at Johns Hopkins and the lead author of a new study. The finding suggests that people with more education have brains that are better able to "find ways around the damage" caused by an injury, he says.
The study looked at the medical records of 769 adults who suffered traumatic brain injuries serious enough to require an inpatient hospital stay and rehabilitation. A year after the injury, just 10 percent of people who didn't finish high school had no disability, compared with 39 percent of people with enough years of education to have received a college degree. People with advanced degrees did even better.
One reason for the difference may be something known as "cognitive reserve" in the brain, Schneider says. The concept is a bit like physical fitness, he says, which can help a person recover from a physical injury. Similarly, a person with a lot of cognitive reserve may be better equipped to recover from a brain injury.
The results were reported Tuesday in the journal Neurology.
Scientists don't fully understand what specific brain changes are responsible for cognitive reserve. But research on educational training suggests that it involves strengthening the networks of brain cells involved in learning and memory, according to a commentary by Erin Bigler that accompanies the study. A stronger network may be better at repairing itself or adapting to damage, Bigler says.
For several decades, studies have shown that people with more education, and presumably more cognitive reserve, are less likely to develop the memory and thinking problems of Alzheimer's disease. The new study suggests the benefits of education and cognitive reserve extend to brain damage caused by injury rather than disease.
There's no guaranteed way to increase your cognitive reserve, Schneider says. But there are hints that staying physically and socially active helps, and that "pursuing lifelong learning may be beneficial," he says.