Exploring the Health Gap Between Rich and Poor
Researcher suggests intelligence may explain disparity among groups
Karen Patterson, The Dallas Morning News, Mar. 14
Social scientists have long noted a broad and powerful link between wealth and health.
On its surface, the connection seems like a no-brainer: More money improves access to doctors, medicines and other advantages that keep people in the pink.
Yet when scientists look further, the issue is a brainteaser: For some unknown reason, increasing availability of medical care, which improves health overall, actually can widen the wealth-health gap.
That unknown reason, an intelligence researcher suggests, could be brainpower.
In two recent scientific papers, researcher Linda Gottfredson proposes that rather than poverty causing ill health (and, generally, lower IQ scores) among lower social classes, intelligence disparities may underlie class differences both in wealth and health.
Consider a person’s income, or job, or education — all signposts of a person’s status and wealth. The more tightly such a factor is related to intelligence, Dr. Gottfredson says, the more tightly it is also related to health.
It’s important to note, she says, that all social classes include people with all ranges of mental ability. But the lower the social class, the higher the proportion of people with limited learning, literacy and problem-solving skills.
“This is something that I could be easily misunderstood on. I’m trying to explain why social groups differ, not why individuals differ,” she emphasizes.
Regarding health, general intelligence may be a major cause of that difference, she contends. While so far it’s unproven, “I think it’s a stronger candidate than anything else that’s been produced so far.”
A host of other possibilities have been suggested: pollution, stress, lack of social support in poor areas — and people’s degree of control over their own lives.
Attributing the health gap to intelligence differences is not a new idea, notes Michael Oakes, assistant professor of epidemiology at the University of Minnesota.
But Dr. Gottfredson deserves credit for replacing vague notions of intelligence with firmer, better-defined parameters, he says.
Still, to Dr. Oakes, there’s no question that poverty is behind major disparities in health. “Ask any physician working in an inner-city hospital,” he writes in an e-mail.
Dr. Gottfredson, however, sees abundant evidence suggesting that intelligence differences may explain the puzzling gap — which exists, she notes, across different time periods, nations, health-care systems and even diseases.
For instance, she says, the higher people are on the socioeconomic ladder, the higher they tend to score on tests of general intelligence, or g — a mental agility that includes skills such as reasoning and learning in all sorts of situations. This agility comes in handy for a host of day-to-day tasks, says Dr. Gottfredson, a professor of education at the University of Delaware. In tasks that are complex — like certain jobs, typically higher-paying ones — g is a strong predictor of performance.
Dr. Gottfredson argues that taking care of one’s health can be viewed as an increasingly complex, lifelong job. Much of this job is shifting from doctor to patient, as medicine’s focus shifts from treatment of acute ills to prevention and management of chronic ones.
Even if all patients had the same medical care and resources, some would exploit them better than others to guard their health, she says. “The reason is that people differ in their ability to learn information, to understand the information that’s provided to them, and their inclination and ability to go seek out information, understand what’s relevant,” she says.
Diseases such as asthma or diabetes tax a patient’s mental resources, Dr. Gottfredson writes in January’s issue of the Journal of Personality and Social Psychology. Patients have to continually decide how to take care of themselves based upon their own day-to-day monitoring of their condition.
With the blood-sugar vigilance diabetes can require, “you have to make judgments all day,” says Dr. Gottfredson, who is also co-director of the Delaware-Johns Hopkins Project for the Study of Intelligence and Society. “It’s not a formula. Your doctor can’t tell you what to do; he or she’s not there all during the day.”
And health care isn’t like high school, where you can just skip a class like calculus if you don’t think you can handle it, she says. “If this is a heart treatment, you don’t want to say, ‘I’ll skip the complicated one.’ “ A heart patient may go home from the doctor’s with diet and exercise regimens, follow-up appointments and various other instructions to decipher.
Health literacy tests illuminate the problem’s severity. Dr. Gottfredson cites a 1995 finding that more than a quarter of some 2,600 patients struggled to understand when their next appointment was scheduled. Forty-two percent didn’t grasp directions for taking medicine on an empty stomach.
Dr. Gottfredson also enlists more general tests, of overall or “functional” literacy, to make her case. While one such test, the 1992 National Adult Literacy Survey, was not designed to measure g, it captures — for people without any language barriers — the same type of learning, problem solving and processing skills, she says. The more poorly people performed on that test, the more likely they were to have some trait associated with low socioeconomic status, like being out of work or poor.
The test measures ability to follow directions, figure out charts, grasp the gist of written passages — skills not so different from those required to maintain health, Dr. Gottfredson says.
Inability to master any given task, like reading a bus schedule, can seem inconsequential. But metaphorically speaking, a lifetime of missed buses adds up, she argues. “Even small odds in one’s favor can produce big profits in the long term when they remain consistently in one’s favor,” she writes.
New research that compares childhood intelligence and lifelong health suggests that such a cumulative process might be at work. That study, led by psychologist Ian Deary, mined data from intelligence testing broadly administered among schoolchildren in Scotland as long as seven decades ago.
Follow-up data revealed that intelligence at about age 11 could predict differences in adult sickness and death rates even after scientists accounted for socioeconomic status. The team reported the data in the same issue of the Journal of Personality and Social Psychology.
Among the findings: Higher childhood intelligence was linked to higher survival chances until about age 76. And intelligence didn’t seem to influence which of the subjects started smoking. But those with higher scores were more likely to later quit.
Childhood IQ, the researchers reported, may relate to health in several ways: It may reflect prior health insults, such as could trace even to the womb; it may reflect the body’s overall integrity; it may predict healthy behaviors; or it may predict a life lived in healthier environments, such as less risky jobs.
In a paper appearing last month in Current Directions in Psychological Science, Dr. Gottfredson and Dr. Deary, of the University of Edinburgh in Scotland, examine the issue further. Differing social opportunities can’t explain why IQ is related to health, they write — the Scottish data show that even after adjusting for poverty and social status in the 1970s, intelligence’s link to sickness and death rates held.
Differences in mental resources may influence not just self-health care, but accident prevention, the team suggests, noting a possible link between intelligence and whether someone is, perhaps, capable of “driving defensively” through life.
Overall, observers contend, research has shown only that intelligence and health disparities are linked, not that intelligence is behind the disparities.
“Correlational methods never prove a causal link,” argues intelligence expert Robert Sternberg, director of the Center for the Psychology of Abilities, Competencies, and Expertise at Yale University. “They merely demonstrate an association.
“Wellness is also associated with many other factors,” he writes in an e-mail, “such as socioeconomic well-being. However, it makes sense that there would be some correlation, in that someone with a very low IQ would be less able to take care of him or herself.”
Dr. Oakes, too, differs with Dr. Gottfredson’s interpretation and emphasis of some previous research. And a big problem, he says, is that her thesis can’t be proved with experiments. Scientists can’t just put two groups of people with differing levels of intelligence in the exact same social conditions, or assign many people of similar intelligence to different conditions.
“She might be able to get close, but she’s not going to be able to give definitive answers as one might, say, be able to for a clinical trial for a drug,” Dr. Oakes says.
He thinks g is less innate and more vulnerable to social influences than Dr. Gottfredson does. Identical twins, separated at birth into a prosperous and a poor household, he argues, would later reflect those conditions with differing levels of success and intelligence. And, presumably, health.
Yet if this were just a question of material resources, Dr. Gottfredson contends, research would show some threshold where people had enough — and more wouldn’t enhance health any further. “But what they find is that there’s no threshold; the higher the level of social status, the lower the level of mortality and morbidity,” she says. That meshes with findings about intelligence, because there’s never a point at which more g doesn’t matter, she says. “The tailwind never fades; the more you have, the just a little bit better the odds are.”
Nevertheless, Dr. Oakes maintains that the health gap is more a problem — and a responsibility — of society than of the individual. In Dr. Gottfredson’s view, he says, “people with low g aren’t succeeding because they have low g. But they’re only not succeeding because the society around them isn’t supportive of low g .”
Even if society were more supportive, he’s not sure it would matter much to public health — especially if g can’t be changed.
Viewing health care as a job could help, says Dr. Gottfredson, because lessons from the workplace could be applied. “This is where I think you have leverage. You’re not going to change people’s intelligence, but you can change tasks.”
Perhaps a simple intelligence screening test could be given to patients, so doctors could tailor their explanations and instructions. Or medical students could receive more thorough training in patient communication. “Bright people tend to greatly overestimate the abilities of the average person,” Dr. Gottfredson says, and “the person who is below average is going to hide that they don’t understand.”
Health aides, druggists and others could also make sure patients grasp what they need to know. “I think the way to make a difference is … to see the opportunities for infusing, you might say, mental assistance,” Dr. Gottfredson says.
Dr. Oakes says the challenge is to structure social systems so people ranging from genius to mentally retarded all have the best chance for good health. “Ultimately, we must ask whether we as a society are comfortable with health disparities, especially in infant mortality where the infant cannot be blamed for its decisions or level of g,” Dr. Oakes writes in his e-mail.
He suspects Dr. Gottfredson shares such concerns. “It’s just a matter of emphasis — where do you want to place your resources and your energy?”